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Author Hartogh, P.; Jarchow, C.; Lellouch, E.; de Val-Borro, M.; Rengel, M.; Moreno, R.; Medvedev, A. S.; Sagawa, H.; Swinyard, B. M.; Cavalié, T.; Lis, D. C.; BłÄ™cka, M. I.; Banaszkiewicz, M.; Bockelée-Morvan, D.; Crovisier, J.; Encrenaz, T.; Küppers, M.; Lara, L.-M.; Szutowicz, S.; Vandenbussche, B.; Bensch, F.; Bergin, E. A.; Billebaud, F.; Biver, N.; Blake, G. A.; Blommaert, J. A. D. L.; Cernicharo, J.; Decin, L.; Encrenaz, P.; Feuchtgruber, H.; Fulton, T.; de Graauw, T.; Jehin, E.; Kidger, M.; Lorente, R.; Naylor, D. A.; Portyankina, G.; Sánchez-Portal, M.; Schieder, R.; Sidher, S.; Thomas, N.; Verdugo, E.; Waelkens, C.; Whyborn, N.; Teyssier, D.; Helmich, F.; Roelfsema, P.; Stutzki, J.; LeDuc, H. G.; Stern, J. A. doi  openurl
  Title Herschel/HIFI observations of Mars: First detection of O2 at submillimetre wavelengths and upper limits on HCl and H2O2 Type (up) Journal Article
  Year 2010 Publication Astron. Astrophys. Abbreviated Journal  
  Volume 521 Issue Pages L49  
  Keywords HEB mixer applications, HIFI, Herschel, planets and satellites: atmospheres / radiative transfer / submillimeter: general / molecular processes  
  Abstract We report on an initial analysis of Herschel/HIFI observations of hydrogen chloride (HCl), hydrogen peroxide (H2O2), and molecular oxygen (O2) in the Martian atmosphere performed on 13 and 16 April 2010 (Ls ~ 77°). We derived a constant volume mixing ratio of 1400 ± 120 ppm for O2 and determined upper limits of 200 ppt for HCl and 2 ppb for H2O2. Radiative transfer model calculations indicate that the vertical profile of O2 may not be constant. Photochemical models determine the lowest values of H2O2 to be around Ls ~ 75° but overestimate the volume mixing ratio compared to our measurements.  
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  Call Number Serial 1093  
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Author Maret, S.; Bacmann, A.; Bottinelli, S.; Parise, B.; Caux, E.; Faure, A.; Bergin, E. A.; Blake, G. A.; Castets, A.; Ceccarelli, C.; Cernicharo, J.; Coutens, A.; Crimier, N.; Demyk, K.; Dominik, C.; Gerin, M.; Hennebelle, P.; Henning, T.; Kahane, C.; Klotz, A.; Melnick, G.; Pagani, L.; Schilke, P.; Vastel, C.; Wakelam, V.; Walters, A.; Baudry, A.; Bell, T.; Benedettini, M.; Boogert, A.; Cabrit, S.; Caselli, P.; Codella, C.; Comito, C.; Encrenaz, P.; Falgarone, E.; Fuente, A.; Goldsmith, P. F.; Helmich, F.; Herbst, E.; Jacq, T.; Kama, M.; Langer, W.; Lefloch, B.; Lis, D.; Lord, S.; Lorenzani, A.; Neufeld, D.; Nisini, B.; Pacheco, S.; Phillips, T.; Salez, M.; Saraceno, P.; Schuster, K.; Tielens, X.; van der Tak, F.; van der Wiel, M. H. D.; Viti, S.; Wyrowski, F.; Yorke, H. doi  openurl
  Title Nitrogen hydrides in the cold envelope of IRAS 16293-2422 Type (up) Journal Article
  Year 2010 Publication Astron. Astrophys. Abbreviated Journal  
  Volume 521 Issue Pages L52  
  Keywords HEB mixer applications, HIFI, Herschel, ISM: abundances / ISM: general / astrochemistry  
  Abstract Nitrogen is the fifth most abundant element in the Universe, yet the gas-phase chemistry of N-bearing species remains poorly understood. Nitrogen hydrides are key molecules of nitrogen chemistry. Their abundance ratios place strong constraints on the production pathways and reaction rates of nitrogen-bearing molecules. We observed the class 0 protostar IRAS 16293-2422 with the heterodyne instrument HIFI, covering most of the frequency range from 0.48 to 1.78 THz at high spectral resolution. The hyperfine structure of the amidogen radical o-NH2 is resolved and seen in absorption against the continuum of the protostar. Several transitions of ammonia from 1.2 to 1.8 THz are also seen in absorption. These lines trace the low-density envelope of the protostar. Column densities and abundances are estimated for each hydride. We find that NH:NH2:NH3 â‰<2c6> 5:1:300. Dark clouds chemical models predict steady-state abundances of NH2 and NH3 in reasonable agreement with the present observations, whilst that of NH is underpredicted by more than one order of magnitude, even using updated kinetic rates. Additional modelling of the nitrogen gas-phase chemistry in dark-cloud conditions is necessary before having recourse to heterogen processes.  
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  Call Number Serial 1094  
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Author Joblin, C.; Pilleri, P.; Montillaud, J.; Fuente, A.; Gerin, M.; Berné, O.; Ossenkopf, V.; Le Bourlot, J.; Teyssier, D.; Goicoechea, J. R.; Le Petit, F.; Röllig, M.; Akyilmaz, M.; Benz, A. O.; Boulanger, F.; Bruderer, S.; Dedes, C.; France, K.; Güsten, R.; Harris, A.; Klein, T.; Kramer, C.; Lord, S. D.; Martin, P. G.; Martin-Pintado, J.; Mookerjea, B.; Okada, Y.; Phillips, T. G.; Rizzo, J. R.; Simon, R.; Stutzki, J.; van der Tak, F.; Yorke, H. W.; Steinmetz, E.; Jarchow, C.; Hartogh, P.; Honingh, C. E.; Siebertz, O.; Caux, E.; Colin, B. doi  openurl
  Title Gas morphology and energetics at the surface of PDRs: New insights with Herschel observations of NGC 7023 Type (up) Journal Article
  Year 2010 Publication Astron. Astrophys. Abbreviated Journal  
  Volume 521 Issue Pages L25  
  Keywords HEB mixer applications, HIFI, Herschel, ISM: structure / ISM: kinematics and dynamics / ISM: molecules / submillimeter: ISM  
  Abstract Context. We investigate the physics and chemistry of the gas and dust in dense photon-dominated regions (PDRs), along with their dependence on the illuminating UV field.

Aims. Using Herschel/HIFI observations, we study the gas energetics in NGC 7023 in relation to the morphology of this nebula. NGC 7023 is the prototype of a PDR illuminated by a B2V star and is one of the key targets of Herschel.

Methods. Our approach consists in determining the energetics of the region by combining the information carried by the mid-IR spectrum (extinction by classical grains, emission from very small dust particles) with that of the main gas coolant lines. In this letter, we discuss more specifically the intensity and line profile of the 158 μm (1901 GHz) [C ii] line measured by HIFI and provide information on the emitting gas.

Results. We show that both the [C ii] emission and the mid-IR emission from polycyclic aromatic hydrocarbons (PAHs) arise from the regions located in the transition zone between atomic and molecular gas. Using the Meudon PDR code and a simple transfer model, we find good agreement between the calculated and observed [C ii] intensities.

Conclusions. HIFI observations of NGC 7023 provide the opportunity to constrain the energetics at the surface of PDRs. Future work will include analysis of the main coolant line [O i] and use of a new PDR model that includes PAH-related species.		  
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  Call Number Serial 1095  
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Author Justtanont, K.; Decin, L.; Schöier, F. L.; Maercker, M.; Olofsson, H.; Bujarrabal, V.; Marston, A. P.; Teyssier, D.; Alcolea, J.; Cernicharo, J.; Dominik, C.; de Koter, A.; Melnick, G.; Menten, K.; Neufeld, D.; Planesas, P.; Schmidt, M.; Szczerba, R.; Waters, R.; de Graauw, Th.; Whyborn, N.; Finn, T.; Helmich, F.; Siebertz, O.; Schmülling, F.; Ossenkopf, V.; Lai, R. doi  openurl
  Title A HIFI preview of warm molecular gas around χ Cygni: first detection of H2O emission toward an S-type AGB star Type (up) Journal Article
  Year 2010 Publication Astron. Astrophys. Abbreviated Journal  
  Volume 521 Issue Pages L6  
  Keywords HEB mixer applications, HIFI, Herschel, stars: AGB and post-AGB / circumstellar matter / stars: kinematics and dynamics / stars: individual: χ Cyg / stars: late-type / stars: mass-loss  
  Abstract Aims. A set of new, sensitive, and spectrally resolved, sub-millimeter line observations are used to probe the warm circumstellar gas around the S-type AGB star χ Cyg. The observed lines involve high rotational quantum numbers, which, combined with previously obtained lower-frequency data, make it possible to study in detail the chemical and physical properties of, essentially, the entire circumstellar envelope of χ Cyg.

Methods. The data were obtained using the HIFI instrument aboard Herschel, whose high spectral resolution provides valuable information about the line profiles. Detailed, non-LTE, radiative transfer modelling, including dust radiative transfer coupled with a dynamical model, has been performed to derive the temperature, density, and velocity structure of the circumstellar envelope.

Results. We report the first detection of circumstellar H2O rotational emission lines in an S-star. Using the high-J CO lines to derive the parameters for the circumstellar envelope, we modelled both the ortho- and para-H2O lines. Our modelling results are consistent with the velocity structure expected for a dust-driven wind. The derived total H2O abundance (relative to H2) is (1.1±0.2) × 10-5, much lower than that in O-rich stars. The derived ortho-to-para ratio of 2.1±0.6 is close to the high-temperature equilibrium limit, consistent with H2O being formed in the photosphere.		  
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  Call Number Serial 1096  
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Author Loenen, A. F.; van der Werf, P. P.; Güsten, R.; Meijerink, R.; Israel, F. P.; Requena-Torres, M. A.; García-Burillo, S.; Harris, A. I.; Klein, T.; Kramer, C.; Lord, S.; Martín-Pintado, J.; Röllig, M.; Stutzki, J.; Szczerba, R.; Weiß, A.; Philipp-May, S.; Yorke, H.; Caux, E.; Delforge, B.; Helmich, F.; Lorenzani, A.; Morris, P.; Philips, T. G.; Risacher, C.; Tielens, A. G. G. M. doi  openurl
  Title Excitation of the molecular gas in the nuclear region of M 82 Type (up) Journal Article
  Year 2010 Publication Astron. Astrophys. Abbreviated Journal  
  Volume 521 Issue Pages L2  
  Keywords HEB mixer applications, HIFI, Herschel, galaxies: individual: M 82 / submillimeter: ISM / ISM: molecules / galaxies: ISM / galaxies: starburst  
  Abstract We present high-resolution HIFI spectroscopy of the nucleus of the archetypical starburst galaxy M 82. Six 12CO lines, 2 13CO lines and 4 fine-structure lines have been detected. Besides showing the effects of the overall velocity structure of the nuclear region, the line profiles also indicate the presence of multiple components with different optical depths, temperatures, and densities in the observing beam. The data have been interpreted using a grid of PDR models. It is found that the majority of the molecular gas is in low density (n = 103.5 cm-3) clouds, with column densities of NH = 1021.5 cm-2 and a relatively low UV radiation field (G0 = 102). The remaining gas is predominantly found in clouds with higher densities (n = 105 cm-3) and radiation fields (G0 = 102.75), but somewhat lower column densities (NH = 1021.2 cm-2). The highest J CO lines are dominated by a small (1% relative surface filling) component, with an even higher density (n = 106 cm-3) and UV field (G0 = 103.25). These results show the strength of multi-component modelling for interpretating the integrated properties of galaxies.  
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  Call Number Serial 1097  
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Author Melnick, G. J.; Tolls, V.; Neufeld, D. A.; Bergin, E. A.; Phillips, T. G.; Wang, S.; Crockett, N. R.; Bell, T. A.; Blake, G. A.; Cabrit, S.; Caux, E.; Ceccarelli, C.; Cernicharo, J.; Comito, C.; Daniel, F.; Dubernet, M.-L.; Emprechtinger, M.; Encrenaz, P.; Falgarone, E.; Gerin, M.; Giesen, T. F.; Goicoechea, J. R.; Goldsmith, P. F.; Herbst, E.; Joblin, C.; Johnstone, D.; Langer, W. D.; Latter, W. D.; Lis, D. C.; Lord, S. D.; Maret, S.; Martin, P. G.; Menten, K. M.; Morris, P.; Müller, H. S. P.; Murphy, J. A.; Ossenkopf, V.; Pagani, L.; Pearson, J. C.; Pérault, M.; Plume, R.; Qin, S.-L.; Salez, M.; Schilke, P.; Schlemmer, S.; Stutzki, J.; Trappe, N.; van der Tak, F. F. S.; Vastel, C.; Yorke, H. W.; Yu, S.; Zmuidzinas, J. doi  openurl
  Title Herschel observations of EXtra-Ordinary Sources (HEXOS): Observations of H2O and its isotopologues towards Orion KL Type (up) Journal Article
  Year 2010 Publication Astron. Astrophys. Abbreviated Journal  
  Volume 521 Issue Pages L27  
  Keywords HEB mixer applications, HIFI, Herschel, ISM: abundances / ISM: molecules  
  Abstract We report the detection of more than 48 velocity-resolved ground rotational state transitions of H216O, H218O, and H217O – most for the first time – in both emission and absorption toward Orion KL using Herschel/HIFI. We show that a simple fit, constrained to match the known emission and absorption components along the line of sight, is in excellent agreement with the spectral profiles of all the water lines. Using the measured H218O line fluxes, which are less affected by line opacity than their H216O counterparts, and an escape probability method, the column densities of H218O associated with each emission component are derived. We infer total water abundances of 7.4 × 10-5, 1.0 × 10-5, and 1.6 × 10-5 for the plateau, hot core, and extended warm gas, respectively. In the case of the plateau, this value is consistent with previous measures of the Orion-KL water abundance as well as those of other molecular outflows. In the case of the hot core and extended warm gas, these values are somewhat higher than water abundances derived for other quiescent clouds, suggesting that these regions are likely experiencing enhanced water-ice sublimation from (and reduced freeze-out onto) grain surfaces due to the warmer dust in these sources.  
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  Call Number Serial 1098  
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Author Mookerjea, B.; Giesen, T.; Stutzki, J.; Cernicharo, J.; Goicoechea, J. R.; De Luca, M.; Bell, T. A.; Gupta, H.; Gerin, M.; Persson, C. M.; Sonnentrucker, P.; Makai, Z.; Black, J.; Boulanger, F.; Coutens, A.; Dartois, E.; Encrenaz, P.; Falgarone, E.; Geballe, T.; Godard, B.; Goldsmith, P. F.; Gry, C.; Hennebelle, P.; Herbst, E.; Hily-Blant, P.; Joblin, C.; Ka<c5><ba>mierczak, M.; Kołos, R.; Krełowski, J.; Lis, D. C.; Martin-Pintado, J.; Menten, K. M.; Monje, R.; Pearson, J. C.; Perault, M.; Phillips, T. G.; Plume, R.; Salez, M.; Schlemmer, S.; Schmidt, M.; Teyssier, D.; Vastel, C.; Yu, S.; Dieleman, P.; Güsten, R.; Honingh, C. E.; Morris, P.; Roelfsema, P.; Schieder, R.; Tielens, A. G. G. M.; Zmuidzinas, J. doi  openurl
  Title Excitation and abundance of C3 in star forming cores. Herschel/HIFI observations of the sight-lines to W31C and W49N Type (up) Journal Article
  Year 2010 Publication Astron. Astrophys. Abbreviated Journal  
  Volume 521 Issue Pages L13  
  Keywords HEB mixer applications, HIFI, Herschel, ISM: lines and bands / ISM: molecules / radiative transfer / ISM: individual objects: W49N / ISM: individual objects: W31C  
  Abstract We present spectrally resolved observations of triatomic carbon (C3) in several ro-vibrational transitions between the vibrational ground state and the low-energy ν2 bending mode at frequencies between 1654–1897 GHz along the sight-lines to the submillimeter continuum sources W31C and W49N, using Herschel's HIFI instrument. We detect C3 in absorption arising from the warm envelope surrounding the hot core, as indicated by the velocity peak position and shape of the line profile. The sensitivity does not allow to detect C3 absorption due to diffuse foreground clouds. From the column densities of the rotational levels in the vibrational ground state probed by the absorption we derive a rotation temperature (Trot) of ~50-70 K, which is a good measure of the kinetic temperature of the absorbing gas, as radiative transitions within the vibrational ground state are forbidden. It is also in good agreement with the dust temperatures for W31C and W49N. Applying the partition function correction based on the derived Trot, we get column densities N(C3) ~ 7–9 × 1014 cm-2 and abundance x(C3) ~ 10-8 with respect to H2. For W31C, using a radiative transfer model including far-infrared pumping by the dust continuum and a temperature gradient within the source along the line of sight we find that a model with x(C3) = 10-8, Tkin = 30–50 K, N(C3) = 1.5 × 1015 cm-2 fits the observations reasonably well and provides parameters in very good agreement with the simple excitation analysis.  
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  Call Number Serial 1099  
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Author Pineda, J. L.; Langer, W. D.; Velusamy, T.; Goldsmith, P. F. doi  openurl
  Title A Herschel [C ii] Galactic plane survey. I. The global distribution of ISM gas components Type (up) Journal Article
  Year 2013 Publication Astron. Astrophys. Abbreviated Journal  
  Volume 554 Issue Pages A103  
  Keywords HEB mixer applications, HIFI, Herschel, ISM: general / stars: formation / evolution / ISM: clouds / ISM: structure / submillimeter: ISM  
  Abstract Context. The [C ii] 158 μm line is an important tool for understanding the life cycle of interstellar matter. Ionized carbon is present in a variety of phases of the interstellar medium (ISM), including the diffuse ionized medium, warm and cold atomic clouds, clouds in transition from atomic to molecular, and dense and warm photon dominated regions.

Aims. Velocity-resolved observations of [C ii] are the most powerful technique available to disentangle the emission produced by these components. These observations can also be used to trace CO-dark H2 gas and determine the total mass of the ISM.

Methods. The Galactic Observations of Terahertz C+ (GOT C+) project surveys the [C ii] 158 μm line over the entire Galactic disk with velocity-resolved observations using the Herschel/HIFI instrument. We present the first longitude-velocity maps of the [C ii] emission for Galactic latitudes b = 0°, ±0.5°, and ±1.0°. We combine these maps with those of H i, 12CO, and 13CO to separate the different phases of the ISM and study their properties and distribution in the Galactic plane.

Results. [C ii] emission is mostly associated with spiral arms, mainly emerging from Galactocentric distances between 4 and 10 kpc. It traces the envelopes of evolved clouds as well as clouds that are in the transition between atomic and molecular. We estimate that most of the observed [C ii] emission is produced by dense photon dominated regions (~47%), with smaller contributions from CO-dark H2 gas (~28%), cold atomic gas (~21%), and ionized gas (~4%). Atomic gas inside the Solar radius is mostly in the form of cold neutral medium (CNM), while the warm neutral medium gas dominates the outer galaxy. The average fraction of CNM relative to total atomic gas is ~43%. We find that the warm and diffuse CO-dark H2 is distributed over a larger range of Galactocentric distances (4–11 kpc) than the cold and dense H2 gas traced by 12CO and 13CO (4–8 kpc). The fraction of CO-dark H2 to total H2 increases with Galactocentric distance, ranging from ~20% at 4 kpc to ~80% at 10 kpc. On average, CO-dark H2 accounts for ~30% of the molecular mass of the Milky Way. When the CO-dark H2 component is included, the radial distribution of the CO-to-H2 conversion factor is steeper than that when only molecular gas traced by CO is considered. Most of the observed [C ii] emission emerging from dense photon dominated regions is associated with modest far-ultraviolet fields in the range χ0 â‰<192> 1 – 30.		  
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  Call Number Serial 1100  
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Author Pineda, J. L.; Velusamy, T.; Langer, W. D.; Goldsmith, P. F.; Li, D.; Yorke, H. W. doi  openurl
  Title A sample of [C II] clouds tracing dense clouds in weak FUV fields observed by Herschel Type (up) Journal Article
  Year 2010 Publication Astron. Astrophys. Abbreviated Journal  
  Volume 521 Issue Pages L19  
  Keywords HEB mixer applications, HIFI, Herschel, ISM: structure / photon-dominated region / ISM: supernova remnants / evolution  
  Abstract The [C ii] fine-structure line at 158 μm is an excellent tracer of the warm diffuse gas in the ISM and the interfaces between molecular clouds and their surrounding atomic and ionized envelopes. Here we present the initial results from Galactic observations of terahertz C+ (GOT C+), a Herschel key project devoted to studying the [C ii] emission in the Galactic plane using the HIFI instrument. We used the [C ii] emission, together with observations of CO, as a probe to understand the effects of newly formed stars on their interstellar environment and characterize the physical and chemical state of the star-forming gas. We collected data along 16 lines-of-sight passing near star-forming regions in the inner Galaxy near longitudes 330° and 20°. We identified fifty-eight [C ii] components that are associated with high-column density molecular clouds as traced by 13CO emission. We combined [C ii], 12CO, and 13CO observations to derive the physical conditions of the [C ii]-emitting regions in our sample of high-column density clouds based on comparing results from a grid of photon dominated region (PDR) models. From this unbiased sample, our results suggest that most of the [C ii] emission originates in clouds with H2 volume densities between 103.5 and 105.5 cm-3 and weak FUV strength (χ0 = 1–10). We find two regions where our analysis suggest high densities >105 cm-3 and strong FUV fields (χ0 = 104–106), likely associated with massive star formation. We suggest that [C ii] emission in conjunction with CO isotopes is a good tool for differentiating regions of massive star formation (high densities/strong FUV fields) and regions that are distant from massive stars (lower densities/weaker FUV fields) along the line-of-sight.  
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  Call Number Serial 1101  
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Author Velusamy, T.; Langer, W. D.; Pineda, J. L.; Goldsmith, P. F.; Li, D.; Yorke, H. W. doi  openurl
  Title [CII] observations of H2 molecular layers in transition clouds Type (up) Journal Article
  Year 2010 Publication Astron. Astrophys. Abbreviated Journal  
  Volume 521 Issue Pages L18  
  Keywords HEB mixer applications, HIFI, Herschel, ISM: structure / ISM: molecules / ISM: atoms / submillimeter: ISM  
  Abstract We present the first results on the diffuse transition clouds observed in [CII] line emission at 158 μm (1.9 THz) towards Galactic longitudes near 340° (5 LOSs) & 20° (11 LOSs) as part of the HIFI tests and GOT C+ survey. Out of the total 146 [CII] velocity components detected by profile fitting we identify 53 as diffuse molecular clouds with associated 12CO emission but without 13CO emission and characterized by AV < 5 mag. We estimate the fraction of the [CII] emission in the diffuse HI layer in each cloud and then determine the [CII] emitted from the molecular layers in the cloud. We show that the excess [CII] intensities detected in a few clouds is indicative of a thick H2 layer around the CO core. The wide range of clouds in our sample with thin to thick H2 layers suggests that these are at various evolutionary states characterized by the formation of H2 and CO layers from HI and C+, respectively. In about 30% of the clouds the H2 column densities (“dark gas”) traced by the [CII] is 50% or more than that traced by 12CO emission. On the average ~25% of the total H2 in these clouds is in an H2 layer which is not traced by CO. We use the HI, [CII], and 12CO intensities in each cloud along with simple chemical models to obtain constraints on the FUV fields and cosmic ray ionization rates.  
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  Call Number Serial 1102  
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Author Wampfler, S. F.; Herczeg, G. J.; Bruderer, S.; Benz, A. O.; van Dishoeck, E. F.; Kristensen, L. E.; Visser, R.; Doty, S. D.; Melchior, M.; van Kempen, T. A.; Yıldız, U. A.; Dedes, C.; Goicoechea, J. R.; Baudry, A.; Melnick, G.; Bachiller, R.; Benedettini, M.; Bergin, E.; Bjerkeli, P.; Blake, G. A.; Bontemps, S.; Braine, J.; Caselli, P.; Cernicharo, J.; Codella, C.; Daniel, F.; di Giorgio, A. M.; Dominik, C.; Encrenaz, P.; Fich, M.; Fuente, A.; Giannini, T.; de Graauw, Th.; Helmich, F.; Herpin, F.; Hogerheijde, M. R.; Jacq, T.; Johnstone, D.; Jørgensen, J. K.; Larsson, B.; Lis, D.; Liseau, R.; Marseille, M.; Mc Coey, C.; Neufeld, D.; Nisini, B.; Olberg, M.; Parise, B.; Pearson, J. C.; Plume, R.; Risacher, C.; Santiago-García, J.; Saraceno, P.; Shipman, R.; Tafalla, M.; van der Tak, F. F. S.; Wyrowski, F.; Roelfsema, P.; Jellema, W.; Dieleman, P.; Caux, E.; Stutzki, J. doi  openurl
  Title Herschel observations of the hydroxyl radical (OH) in young stellar objects Type (up) Journal Article
  Year 2010 Publication Astron. Astrophys. Abbreviated Journal  
  Volume 521 Issue Pages L36  
  Keywords HEB mixer applications, HIFI, Herschel, astrochemistry / stars: formation / ISM: molecules / ISM: jets and outflows / ISM: individual objects: HH 46  
  Abstract Aims. “Water In Star-forming regions with Herschel” (WISH) is a Herschel key program investigating the water chemistry in young stellar objects (YSOs) during protostellar evolution. Hydroxyl (OH) is one of the reactants in the chemical network most closely linked to the formation and destruction of H2O. High-temperature (T 250 K) chemistry connects OH and H2O through the OH + H2 H2O + H reactions. Formation of H2O from OH is efficient in the high-temperature regime found in shocks and the innermost part of protostellar envelopes. Moreover, in the presence of UV photons, OH can be produced from the photo-dissociation of H2O through H2O + γUV OH + H.

Methods. High-resolution spectroscopy of the 163.12 μm triplet of OH towards HH 46 and NGC 1333 IRAS 2A was carried out with the Heterodyne Instrument for the Far Infrared (HIFI) on board the Herschel Space Observatory. The low- and intermediate-mass protostars HH 46, TMR 1, IRAS 15398-3359, DK Cha, NGC 7129 FIRS 2, and NGC 1333 IRAS 2A were observed with the Photodetector Array Camera and Spectrometer (PACS) on Herschel in four transitions of OH and two [O i] lines.

Results. The OH transitions at 79, 84, 119, and 163 μm and [O i] emission at 63 and 145μm were detected with PACS towards the class I low-mass YSOs as well as the intermediate-mass and class I Herbig Ae sources. No OH emission was detected from the class 0 YSO NGC 1333 IRAS 2A, though the 119 μm was detected in absorption. With HIFI, the 163.12 μm was not detected from HH 46 and only tentatively detected from NGC 1333 IRAS 2A. The combination of the PACS and HIFI results for HH 46 constrains the line width (FWHM 11 km s-1) and indicates that the OH emission likely originates from shocked gas. This scenario is supported by trends of the OH flux increasing with the [O i] flux and the bolometric luminosity, as found in our sample. Similar OH line ratios for most sources suggest that OH has comparable excitation temperatures despite the different physical properties of the sources.		  
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  Call Number Serial 1103  
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Author Shcherbatenko, M.; Tretyakov, I.; Lobanov, Yu.; Maslennikov, S. N.; Kaurova, N.; Finkel, M.; Voronov, B.; Goltsman, G.; Klapwijk, T. M. doi  openurl
  Title Nonequilibrium interpretation of DC properties of NbN superconducting hot electron bolometers Type (up) Journal Article
  Year 2016 Publication Appl. Phys. Lett. Abbreviated Journal  
  Volume 109 Issue 13 Pages 132602  
  Keywords HEB mixer, contacts  
  Abstract We present a physically consistent interpretation of the dc electrical properties of niobiumnitride (NbN)-based superconducting hot-electron bolometer mixers, using concepts of nonequilibrium superconductivity. Through this, we clarify what physical information can be extracted from the resistive transition and the dc current-voltage characteristics, measured at suitably chosen temperatures, and relevant for device characterization and optimization. We point out that the intrinsic spatial variation of the electronic properties of disordered superconductors, such as NbN, leads to a variation from device to device.  
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  Notes Approved no  
  Call Number Serial 1107  
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Author Klapwijk, T. M.; Semenov, A. V. url  doi
openurl 
  Title Engineering physics of superconducting hot-electron bolometer mixers Type (up) Journal Article
  Year 2017 Publication IEEE Trans. THz Sci. Technol. Abbreviated Journal IEEE Trans. THz Sci. Technol.  
  Volume 7 Issue 6 Pages 627-648  
  Keywords HEB mixers  
  Abstract Superconducting hot-electron bolometers are presently the best performing mixing devices for the frequency range beyond 1.2 THz, where good-quality superconductor-insulator-superconductor devices do not exist. Their physical appearance is very simple: an antenna consisting of a normal metal, sometimes a normal-metal-superconductor bilayer, connected to a thin film of a narrow short superconductor with a high resistivity in the normal state. The device is brought into an optimal operating regime by applying a dc current and a certain amount of local-oscillator power. Despite this technological simplicity, its operation has found to be controlled by many different aspects of superconductivity, all occurring simultaneously. A core ingredient is the understanding that there are two sources of resistance in a superconductor: a charge-conversion resistance occurring at a normal-metal-superconductor interface and a resistance due to time-dependent changes of the superconducting phase. The latter is responsible for the actual mixing process in a nonuniform superconducting environment set up by the bias conditions and the geometry. The present understanding indicates that further improvement needs to be found in the use of other materials with a faster energy relaxation rate. Meanwhile, several empirical parameters have become physically meaningful indicators of the devices, which will facilitate the technological developments.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2156-342X ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1292  
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Author Hajenius, M.; Yang, Z. Q.; Gao, J. R.; Baselmans, J. J. A.; Klapwijk, T. M.; Voronov, B.; Gol'tsman, G. url  doi
openurl 
  Title Optimized sensitivity of NbN hot electron bolometer mixers by annealing Type (up) Journal Article
  Year 2007 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 17 Issue 2 Pages 399-402  
  Keywords NbN HEB mixers  
  Abstract We report that the heterodyne sensitivity of superconducting hot-electron bolometers (HEBs) increases by 25-30% after annealing at 85degC in high vacuum. The devices studied are twin-slot antenna coupled mixers with a small area NbN bridge of 1 mum times 0.15 mum, above which there is a SiO 2 passivation layer. The mixer noise temperature, gain, and resistance versus temperature curve of a HEB before and after annealing are compared and analysed. We show that the annealing reduces the intrinsic noise of the mixer by 37% and makes the superconducting transition of the bridge and the contacts sharper. We argue that the reduction ofthe noise is mainly due to the improvement of the transparency of the contact/film interface. The lowest receiver noise temperature of 700 K is measured at a local oscillator frequency of 1.63 THz and at a bath temperature of 4.2 K.  
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  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1426  
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Author Tretyakov, I. V.; Finkel, M. I.; Ryabchun, S. A.; Kardakova, A. I.; Seliverstov, S. V.; Petrenko, D. V.; Goltsman, G. N. url  doi
openurl 
  Title Hot-electron bolometer mixers with in situ contacts Type (up) Journal Article
  Year 2014 Publication Radiophys. Quant. Electron. Abbreviated Journal Radiophys. Quant. Electron.  
  Volume 56 Issue 8-9 Pages 591-598  
  Keywords HEB mixers  
  Abstract We report on the latest achievements in the development of superconducting hot-electron bolometer (HEB) mixers for terahertz superheterodyne receivers. We consider application ranges of such receivers and requirements for the basic characteristics of the mixers. Main features of the mixers, such as noise temperature, gain bandwidth, noise bandwidth, and required local-oscillator power, have been improved significantly over the past few years due to intense research work, both in terms of the element fabrication quality and in terms of understanding of the physics of the processes occurring in the HEB mixers. Contacts between the superconducting bridge and the planar antenna play a key role in the mixer operation. Improvement of the quality of the contacts leads simultaneously to a decrease in the noise temperature and an increase in the gain bandwidth of a mixer.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0033-8443 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1170  
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Author Antipov, S.; Trifonov, A.; Krause, S.; Meledin, D.; Kaurova, N.; Rudzinski, M.; Desmaris, V.; Belitsky, V.; Goltsman, G. url  doi
openurl 
  Title Improved bandwidth of a 2 THz hot-electron bolometer heterodyne mixer fabricated on sapphire with a GaN buffer layer Type (up) Journal Article
  Year 2019 Publication Supercond. Sci. Technol. Abbreviated Journal Supercond. Sci. Technol.  
  Volume 32 Issue 7 Pages 075003  
  Keywords NbN HEB mixer, GaN buffer layer, sapphire substrate  
  Abstract We report on the signal-to-noise and gain bandwidth of a niobium nitride (NbN) hot-electron bolometer (HEB) mixer at 2 THz fabricated on a sapphire substrate with a GaN buffer layer. Two mixers with different DC properties and geometrical dimensions were studied and they demonstrated very close bandwidth performance. The signal-to-noise bandwidth is increased to 8 GHz in comparison to the previous results, obtained without a buffer-layer. The data were taken in a quasi-optical system with the use of the signal-to-noise method, which is close to the signal levels used in actual astrophysical observations. We find an increase of the gain bandwidth to 5 GHz. The results indicate that prior results obtained on a substrate of crystalline GaN can also be obtained on a conventional sapphire substrate with a few micron MOCVD-deposited GaN buffer-layer.  
  Address  
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  Publisher IOP Publishing Place of Publication Editor  
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  Area Expedition Conference  
  Notes Approved no  
  Call Number Antipov_2019 Serial 1277  
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Author Ren, Y.; Zhang, D. X.; Zhou, K. M.; Miao, W.; Zhang, W.; Shi, S. C.; Seleznev, V.; Pentin, I.; Vakhtomin, Y.; Smirnov, K. url  doi
openurl 
  Title 10.6 μm heterodyne receiver based on a superconducting hot-electron bolometer mixer and a quantum cascade laser Type (up) Journal Article
  Year 2019 Publication AIP Advances Abbreviated Journal AIP Advances  
  Volume 9 Issue 7 Pages 075307  
  Keywords NbN HEB mixers, QCL, IR  
  Abstract We report on the development of a heterodyne receiver at mid-infrared wavelength for high-resolution spectroscopy applications. The receiver employs a superconducting NbN hot electron bolometer as a mixer and a room temperature distributed feedback quantum cascade laser operating at 10.6 μm (28.2 THz) as a local oscillator. The stabilization of the heterodyne receiver has been achieved using a feedback loop controlling the output power of the laser. Improved Allan variance times as well as a double sideband receiver noise temperature of 5000 K and a noise bandwidth of 2.8 GHz of the receiver system are demonstrated.

The work is supported in part by the National Key R&D Program of China under Grant 2018YFA0404701, by the CAS program under Grant QYZDJ-SSW-SLH043 and GJJSTD20180003, by the National Natural Science Foundation of China (NSFC) under Grant 11773083, by the “Hundred Talents Program” of the “Pioneer Initiative”, and in part by the CAS Key Lab for Radio Astronomy.		  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2158-3226 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1293  
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Author Tretyakov, I. V.; Anfertyev, V. A.; Revin, L. S.; Kaurova, N. S.; Voronov, B. M.; Vaks, V. L.; Goltsman, G. N. url  doi
openurl 
  Title Sensitivity and resolution of a heterodyne receiver based on the NbN HEB mixer with a quantum-cascade laser as a local oscillator Type (up) Journal Article
  Year 2018 Publication Radiophys. Quant. Electron. Abbreviated Journal Radiophys. Quant. Electron.  
  Volume 60 Issue 12 Pages 988-992  
  Keywords NbN HEB mixer  
  Abstract We present the results of experimental studies of the basic characteristics and operation features of a terahertz heterodyne detector based on the superconducting NbN HEB mixer and a quantum cascade laser as a local oscillator operating at a frequency of 2.02 THz. The measured noise temperature of such a mixer amounted to 1500 K. The spectral resolution of the detector is determined by the width of the local-oscillator spectral line whose measured value does not exceed 1 MHz. The quantum-cascade laser could be linearly tuned with respect to frequency with the coefficient 7.2 MHz/mA within the limits of the current oscillation bandwidth.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0033-8443 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1307  
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Author Seliverstov, S. V.; Anfertyev, V. A.; Tretyakov, I. V.; Ozheredov, I. A.; Solyankin, P. M.; Revin, L. S.; Vaks, V. L.; Rusova, A. A.; Goltsman, G. N.; Shkurinov, A. P. url  doi
openurl 
  Title Terahertz heterodyne receiver with an electron-heating mixer and a heterodyne based on the quantum-cascade laser Type (up) Journal Article
  Year 2017 Publication Radiophys. Quant. Electron. Abbreviated Journal Radiophys. Quant. Electron.  
  Volume 60 Issue 7 Pages 518-524  
  Keywords NbN HEB mixer, QCL  
  Abstract We study characteristics of the laboratory prototype of a terahertz heterodyne receiver with an electron-heating mixer and a heterodyne based on the quantum-cascade laser. The results obtained demonstrate the possibility to use this receiver as a basis for creation of a high-sensitivity terahertz spectrometer, which can be used in many basic and practical applications. A significant advantage of this receiver will be the possibility of placing the mixer and heterodyne in the same cryostat, which will reduce the device dimensions considerably. The obtained experimental results are analyzed, and methods of optimizing the parameters of the receiver are proposed.  
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  ISSN 0033-8443 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1322  
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Author Krause, S.; Mityashkin, V.; Antipov, S.; Gol’tsman, G.; Meledin, D.; Desmaris, V.; Belitsky, V.; Rudziński, M. url  doi
openurl 
  Title Reduction of phonon escape time for nbn hot electron bolometers by using gan buffer layers Type (up) Journal Article
  Year 2017 Publication IEEE Trans. Terahertz Sci. Technol. Abbreviated Journal IEEE Trans. Terahertz Sci. Technol.  
  Volume 7 Issue 1 Pages 53-59  
  Keywords NbN HEB mixer  
  Abstract In this paper, we investigated the influence of the GaN buffer layer on the phonon escape time of phonon-cooled hot electron bolometers (HEBs) based on NbN material and compared our findings to conventionally employed Si substrate. The presented experimental setup and operation of the HEB close to the critical temperature of the NbN film allowed for the extraction of phonon escape time in a simplified manner. Two independent experiments were performed at GARD/Chalmers and MSPU on a similar experimental setup at frequencies of approximately 180 and 140 GHz, respectively, and have shown reproducible and consistent results. By fitting the normalized IF measurement data to the heat balance equations, the escape time as a fitting parameter has been deduced and amounts to 45 ps for the HEB based on Si substrate as in contrast to a significantly reduced escape time of 18 ps for the HEB utilizing the GaN buffer layer under the assumption that no additional electron diffusion has taken place. This study indicates a high phonon transmissivity of the NbN-to-GaN interface and a prospective increase of IF bandwidth for HEB made of NbN on GaN buffer layers, which is desirable for future THz HEB heterodyne receivers.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 2156-3446 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1330  
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Author Trifonov, A.; Tong, C.-Y. E.; Lobanov, Y.; Kaurova, N.; Blundell, R.; Goltsman, G. url  doi
openurl 
  Title Photon absorption near the gap frequency in a hot electron bolometer Type (up) Journal Article
  Year 2017 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 27 Issue 4 Pages 1-4  
  Keywords NBN HEB mixer  
  Abstract The superconducting energy gap is a fundamental characteristic of a superconducting film, which, together with the applied pump power and the biasing setup, defines the instantaneous resistive state of the Hot Electron Bolometer (HEB) mixer at any given bias point on the I-V curve. In this paper we report on a series of experiments, in which we subjected the HEB to radiation over a wide frequency range along with parallel microwave injection. We have observed three distinct regimes of operation of the HEB, depending on whether the radiation is above the gap frequency, far below it or close to it. These regimes are driven by the different patterns of photon absorption. The experiments have allowed us to derive the approximate gap frequency of the device under test as about 585 GHz. Microwave injection was used to probe the HEB impedance. Spontaneous switching between the superconducting (low resistive) state and a quasi-normal (high resistive) state was observed. The switching pattern depends on the particular regime of HEB operation and can assume a random pattern at pump frequencies below the gap to a regular relaxation oscillation running at a few MHz when pumped above the gap.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1558-2515 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1331  
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Author Tong, C.-Y. E.; Trifonov, A.; Shurakov, A.; Blundell, R.; Gol’tsman, G. url  doi
openurl 
  Title A microwave-operated hot-electron-bolometric power detector for terahertz radiation Type (up) Journal Article
  Year 2015 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 25 Issue 3 Pages 2300604 (1 to 4)  
  Keywords NbN HEB mixer  
  Abstract A new class of microwave-operated THz power detectors based on the NbN hot-electron-bolometer (HEB) mixer is proposed. The injected microwave signal ( 1 GHz) serves the dual purpose of pumping the HEB element and enabling the read-out of the internal state of the device. A cryogenic amplifier amplifies the reflected microwave signal from the device and a homodyne scheme recovers the effects of the incident THz radiation. Two modes of operation have been identified, depending on the level of incident radiation. For weak signals, we use a chopper to chop the incident radiation against a black body reference and a lock-in amplifier to perform synchronous detection of the homodyne readout. The voltage measured is proportional to the incident power, and we estimate an optical noise equivalent power of  5pW/ √Hz at 0.83 THz. At higher signal levels, the homodyne circuit recovers the stream of steady relaxation oscillation pulses from the HEB device. The frequency of these pulses is in the MHz frequency range and bears a linear relationship with the incident THz radiation over an input power range of  15 dB. A digital frequency counter is used to measure THz power. The applicable power range is between 1 nW and 1 μW.  
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  Series Volume Series Issue Edition  
  ISSN 1558-2515 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1354  
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Author Shurakov, A.; Tong, C.-Y. E.; Blundell, R.; Kaurova, N.; Voronov, B.; Gol'tsman, G. url  doi
openurl 
  Title Microwave stabilization of a HEB mixer in a pulse-tube cryocooler Type (up) Journal Article
  Year 2013 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 23 Issue 3 Pages 1501504-1501504  
  Keywords NbN HEB mixers  
  Abstract We report the results of our study of the stability of an 800 GHz hot electron bolometer (HEB) mixer cooled with a pulse-tube cryocooler. Pulse-tube cryocoolers introduce temperature fluctuations as well as mechanical vibrations at a frequency of ~1 Hz, both of which can cause receiver gain fluctuations at that frequency. In our system, the motor of the cryocooler was separated from the cryostat to minimize mechanical vibrations, leaving thermal effects as the dominant source of the receiver gain fluctuations. We measured root mean square temperature variations of the 4 K stage of ~7 mK. The HEB mixer was pumped by a solid state local oscillator at 810 GHz. The root mean square current fluctuations at the low noise operating point (1.50 mV, 56.5 μA) were ~0.12 μA, and were predominantly due to thermal fluctuations. To stabilize the bias current, microwave radiation was injected to the HEB mixer. The injected power level was set by a proportional-integral-derivative controller, which completely compensates for the bias current oscillations induced by the pulse-tube cryocooler. Significant improvement in the Allan variance of the receiver output power was obtained, and an Allan time of 5 s was measured.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1372  
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Author Chen, J.; Kang, L.; Jin, B. B.; Xu, W. W.; Wu, P. H.; Zhang, W.; Jiang, L.; Li, N.; Shi, S. C.; Gol'tsman, G. N. url  doi
openurl 
  Title Properties of terahertz superconducting hot electron bolometer mixers Type (up) Journal Article
  Year 2008 Publication Int. J. Terahertz Sci. Technol. Abbreviated Journal Int. J. Terahertz Sci. Technol.  
  Volume 1 Issue 1 Pages 37-41  
  Keywords NbN HEB mixers, noise temperature  
  Abstract A quasi-optical superconducting niobium nitride (NbN) hot electron bolometer (HEB) mixer has been fabricated and measured in the terahertz (THz) frequency range of 0.5~2.52 THz. A receiver noise temperature of 2000 K at 2.52 THz has been obtained for the mixer without corrections. Also, the effect of a Parylene C anti-reflection (AR) coating on the silicon (Si) lens has been studied.  
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  Notes Approved no  
  Call Number Serial 1417  
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Author Ryabchun, S.; Tong, C.-Y. E.; Blundell, R.; Kimberk, R.; Gol'tsman, G. url  doi
openurl 
  Title Study of the effect of microwave radiation on the operation of HEB mixers in the terahertz frequency range Type (up) Journal Article
  Year 2007 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 17 Issue 2 Pages 391-394  
  Keywords NbN HEB mixers  
  Abstract We have investigated the effect of injecting microwave radiation, with a frequency much lower than that corresponding to the energy gap of the superconductor, on the performance of the hot-electron bolometer mixer incorporated into a THz heterodyne receiver. More specifically, we show that exposing the mixer to microwave radiation does not cause a significant rise of the receiver noise temperature and fall of the mixer conversion gain so long as the microwave power is a small fraction of local oscillator power. The injection of a small, but controlled amount of microwave power therefore enables active compensation of local oscillator power and coupling fluctuations which can significantly degrade the gain stability of hot electron bolometer mixer receivers.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1427  
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Author Jiang, L.; Antipov, S. V.; Voronov, B. M.; Gol'tsman, G. N.; Zhang, W.; Li, N.; Lin, Z. H.; Yao, Q. J.; Miao, W.; Shi, S. C.; Svechnikov, S. I.; Vakhtomin, Y. B. url  doi
openurl 
  Title Characterization of the performance of a quasi-optical NbN superconducting HEB mixer Type (up) Journal Article
  Year 2007 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 17 Issue 2 Pages 395-398  
  Keywords NbN HEB mixers, noise temperature  
  Abstract In this paper we focus mainly on the investigation of the performance of a quasi-optical (planar log-spiral antenna) phonon-cooled NbN superconducting hot electron bolometer (HEB) mixer, which is cryogenically cooled by a close-cycled 4-K cryocooler, at 500 and 850 GHz frequency bands. The mixer's noise performance, stability of IF output power, and local oscillator (LO) power requirement are characterized for three NbN superconducting HEB devices of different sizes. The transmission characteristics of Mylar and Zitex films with incidence waves of an elliptical polarization are also examined by measuring the mixer's noise temperature. The lowest receiver noise temperatures (with no corrections) of 750 and 1100 K are measured at 500 and 850 GHz, respectively. Experimental results also demonstrate that the bigger the HEB device is, the higher the stability of IF output power becomes.  
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  ISSN 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1429  
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Author Zhang, Wen; Li, Ning; Jiang, Ling; Miao, Wei; Lin, Zhen-Hui; Yao, Qi-Jun; Shi, Sheng-Cai; Chen, Jian; Wu, Pei-Heng; Svechnikov, S. I.; Vachtomin, Y. B.; Antipov, S. V.; Voronov, B. M.; Gol'tsman, G. N. url  doi
openurl 
  Title Noise behaviour of a THz superconducting hot-electron bolometer mixer Type (up) Journal Article
  Year 2007 Publication Chinese Phys. Lett. Abbreviated Journal Chinese Phys. Lett.  
  Volume 24 Issue 6 Pages 1778-1781  
  Keywords NbN HEB mixers  
  Abstract A quasi-optical superconducting NbN hot-electron bolometer (HEB) mixer is measured in the frequency range of 0.5–2.5 THz for understanding of the frequency dependence of noise temperature of THz coherent detectors. It has been found that noise temperature increasing with frequency is mainly due to the coupling loss between the quasi-optical planar antenna and the superconducting HEB bridge when taking account of non-uniform distribution of high-frequency current. With the coupling loss corrected, the superconducting HEB mixer demonstrates a noise temperature nearly independent of frequency.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0256-307X ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1430  
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Author Baselmans, J. J. A.; Baryshev, A.; Reker, S. F.; Hajenius, M.; Gao, J. R.; Klapwijk, T. M.; Voronov, B.; Gol’tsman, G. url  doi
openurl 
  Title Influence of the direct response on the heterodyne sensitivity of hot electron bolometer mixers Type (up) Journal Article
  Year 2006 Publication J. Appl. Phys. Abbreviated Journal J. Appl. Phys.  
  Volume 100 Issue 8 Pages 084510 (1 to 7)  
  Keywords NbN HEB mixers  
  Abstract We present a detailed experimental study of the direct detection effect in a small volume (0.15μm×1μm×3.5nm) quasioptical NbN phonon cooled hot electron bolometer mixer at 673GHz. We find that the small signal noise temperature, relevant for an astronomical observation, is 20% lower than the noise temperature obtained using 300 and 77K calibration loads. In a separate set of experiments we show that the direct detection effect is caused by a combination of bias current reduction when switching from the 77 to the 300K

load in combination with the bias current dependence of the receiver gain. The bias current dependence of the receiver gain is shown to be mainly caused by the current dependence of the mixer gain.		  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1442  
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Author Kooi, J. W.; Baselmans, J. J. A.; Baryshev, A.; Schieder, R.; Hajenius, M.; Gao, J.R.; Klapwijk, T. M.; Voronov, B.; Gol’tsman, G. url  doi
openurl 
  Title Stability of heterodyne terahertz receivers Type (up) Journal Article
  Year 2006 Publication J. Appl. Phys. Abbreviated Journal J. Appl. Phys.  
  Volume 100 Issue 6 Pages 064904 (1 to 9)  
  Keywords NbN HEB mixers  
  Abstract In this paper we discuss the stability of heterodyne terahertz receivers based on small volume NbN phonon cooled hot electron bolometers (HEBs). The stability of these receivers can be broken down in two parts: the intrinsic stability of the HEB mixer and the stability of the local oscillator (LO) signal injection scheme. Measurements show that the HEB mixer stability is limited by gain fluctuations with a 1∕f spectral distribution. In a 60MHz noise bandwidth this results in an Allan variance stability time of ∼0.3s. Measurement of the spectroscopic Allan variance between two intermediate frequency (IF) channels results in a much longer Allan variance stability time, i.e., 3s between a 2.5 and a 4.7GHz channel, and even longer for more closely spaced channels. This implies that the HEB mixer 1∕f noise is strongly correlated across the IF band and that the correlation gets stronger the closer the IF channels are spaced. In the second part of the paper we discuss atmospheric and mechanical system stability requirements on the LO-mixer cavity path length. We calculate the mixer output noise fluctuations as a result of small perturbations of the LO-mixer standing wave, and find very stringent mechanical and atmospheric tolerance requirements for receivers operating at terahertz frequencies.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1444  
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Author Jiang, Ling; Miao, Wei; Zhang, Wen; Li, Ning; Lin, Zhen Hui; Yao, Qi Jun; Shi, Sheng-Cai; Svechnikov, S. I.; Vakhtomin, Y. B.; Antipov, S. V.; Voronov, B. M.; Kaurova, N. S.; Gol'tsman, G. N. url  doi
openurl 
  Title Characterization of a quasi-optical NbN superconducting HEB mixer Type (up) Journal Article
  Year 2006 Publication IEEE Trans. Microwave Theory Techn. Abbreviated Journal IEEE Trans. Microwave Theory Techn.  
  Volume 54 Issue 7 Pages 2944-2948  
  Keywords NbN HEB mixers  
  Abstract In this paper, the performance of a quasi-optical NbN superconducting hot-electron bolometer (HEB) mixer, cryogenically cooled by a close-cycled 4-K refrigerator, is thoroughly investigated at 300, 500, and 850 GHz. The lowest receiver noise temperatures measured at the respective three frequencies are 1400, 900, and 1350 K, which can go down to 659, 413, and 529 K, respectively, after correcting the loss and associated noise contribution of the quasi-optical system before the measured superconducting HEB mixer. The stability of the quasi-optical superconducting HEB mixer is also investigated here. The Allan variance time measured with a local oscillator pumping at 500 GHz and an IF bandwidth of 110 MHz is 1.5 s at the dc-bias voltage exhibiting the lowest noise temperature and increases to 2.5 s at a dc bias twice that voltage.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0018-9480 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1448  
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Author Yang, Z. Q.; Hajenius, M.; Baselmans, J. J. A.; Gao, J. R.; Voronov, B.; Gol’tsman, G. N. url  doi
openurl 
  Title Reduced noise in NbN hot-electron bolometer mixers by annealing Type (up) Journal Article
  Year 2006 Publication Supercond. Sci. Technol. Abbreviated Journal Supercond. Sci. Technol.  
  Volume 19 Issue 4 Pages L (9 to 12)  
  Keywords NbN HEB mixers  
  Abstract We find that the sensitivity of heterodyne receivers based on superconducting hot-electron bolometers (HEBs) increases by 25–30% after annealing at 85 °C in vacuum. The devices studied are twin-slot antenna coupled mixers with a small NbN bridge of 1 × 0.15 µm2. We show that annealing changes the device properties as reflected in sharper resistive transitions of the complete device, apparently reducing the device-related noise. The lowest receiver noise temperature of 700 K is measured at a local oscillator frequency of 1.63 THz and a bath temperature of 4.3 K.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0953-2048 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1456  
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Author Hübers, H.-W.; Semenov, A.; Holldack, K.; Schade, U.; Wüstefeld, G.; Gol’tsman, G. url  doi
openurl 
  Title Time domain analysis of coherent terahertz synchrotron radiation Type (up) Journal Article
  Year 2005 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.  
  Volume 87 Issue 18 Pages 184103 (1 to 3)  
  Keywords NbN HEB mixers, applications  
  Abstract The time structure of coherent terahertz synchrotron radiation at the electron storage ring of the Berliner Elektronensynchrotron und Speicherring Gesellschaft has been analyzed with a fast superconducting hot-electron bolometer. The emission from a single bunch of electrons was found to last ∼1500ps at frequencies around 0.4THz, which is much longer than the length of an electron bunch in the time domain (∼5ps). It is suggested that this is caused by multiple reflections at the walls of the beam line. The quadratic increase of the power with the number of electrons in the bunch as predicted for coherent synchrotron radiation and the transition from stable to bursting radiation were determined from a single storage ring fill pattern of bunches with different populations.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-6951 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1457  
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Author Loudkov, D.; Tong, C.-Y. E.; Blundell, R.; Kaurova, N.; Grishina, E.; Voronov, B.; Gol’tsman, G. url  doi
openurl 
  Title An investigation of the performance of the superconducting HEB mixer as a function of its RF embedding impedance Type (up) Journal Article
  Year 2005 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 15 Issue 2 Pages 472-475  
  Keywords waveguide NbN HEB mixers  
  Abstract We have conducted an investigation of the optimal embedding impedance for a waveguide superconducting hot-electron bolometric (HEB) mixer. Three mixer chip designs for 800 GHz, offering nominal embedding resistances of 70 /spl Omega/, 35 /spl Omega/, and 15 /spl Omega/, have been developed. We used both High Frequency Structure Simulator (HFSS) software and scale model impedance measurements in the design process. We subsequently fabricated HEB mixers to these designs using 3-4 nm thick NbN thin film. Receiver noise temperature measurements and Fourier Transform Spectrometer (FTS) scans were performed to determine the optimal combination of embedding impedance and normal-state resistance for a 50 Ohm IF load impedance. A receiver noise temperature of 440 K was measured at a local oscillator frequency 850 GHz for a mixer with normal state resistance of 62 /spl Omega/ incorporated into a circuit offering a nominal embedding impedance of 70 /spl Omega/. We conclude from our data that, for low noise operation, the normal state resistance of the HEB mixer element should be close to the embedding impedance of the mixer mount.  
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  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number 1439677 Serial 1464  
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Author Baubert, J.; Salez, M.; Merkel, H.; Pons, P.; Cherednichenko, S.; Lecomte, B.; Drakinsky, V.; Goltsman, G.; Leone, B. url  doi
openurl 
  Title IF gain bandwidth of membrane-based NbN hot electron bolometers for SHAHIRA Type (up) Journal Article
  Year 2005 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 15 Issue 2 Pages 507-510  
  Keywords NbN HEB mixers, applications  
  Abstract SHAHIRA (Submm Heterodyne Array for HIgh-speed Radio Astronomy) is a project supported by the European Space Agency (ESA) and is designed to fly on the SOFIA observatory. A quasi-optic design has been chosen for 2.5/2.7 THz and 4.7 THz, for hydroxyde radical OH, deuterated hydrogen HD and neutral atomic oxygen OI lines observations. Hot electron bolometers (HEBs) have been processed on 1 /spl mu/m thick SiO/sub 2//Si/sub 3/N/sub 4/ stress-less membranes. In this paper we analyse the intermediate frequency (IF) gain bandwidth from the theoretical point of view, and compare it to measurements.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1558-2515 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1468  
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Author Jiang, L.; Li, J.; Zhang, W.; Yao, Q. J.; Lin, Z. L.; Shi, S. C.; Vachtomin, Y. B.; Antipov, S. V.; Svechnikov, S. I.; Voronov, B. M.; Goltsman, G. N. url  doi
openurl 
  Title Characterization of NbN HEB mixers cooled by a close-cycled 4 Kelvin refrigerator Type (up) Journal Article
  Year 2005 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 15 Issue 2 Pages 511-513  
  Keywords NbN HEB mixers  
  Abstract It is quite beneficial to operate superconducting hot-electron-bolometer (HEB) mixers with a close-cycled 4 Kelvin refrigerator for real applications such as astronomy and atmospheric research. In this paper, a phononcooled NbN HEB mixer (quasioptical type) is thoroughly characterized under such a cooling circumstance. The effects of mechanical vibration, electrical interference, and temperature fluctuation of a two-stage Gifford-McMahon 4 Kelvin refrigerator upon the characteristics of the phononcooled NbN HEB mixer are investigated in particular. Detailed measurement results are presented.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1558-2515 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1469  
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Author Meledin, D. V.; Marrone, D. P.; Tong, C.-Y. E.; Gibson, H.; Blundell, R.; Paine, S. N.; Papa, D.C.; Smith, M.; Hunter, T. R.; Battat, J.; Voronov, B.; Gol'tsman, G. url  doi
openurl 
  Title A 1-THz superconducting hot-electron-bolometer receiver for astronomical observations Type (up) Journal Article
  Year 2004 Publication IEEE Trans. Microwave Theory Techn. Abbreviated Journal IEEE Trans. Microwave Theory Techn.  
  Volume 52 Issue 10 Pages 2338-2343  
  Keywords NbN HEB mixer, applications  
  Abstract In this paper, we describe a superconducting hot-electron-bolometer mixer receiver developed to operate in atmospheric windows between 800-1300 GHz. The receiver uses a waveguide mixer element made of 3-4-nm-thick NbN film deposited over crystalline quartz. This mixer yields double-sideband receiver noise temperatures of 1000 K at around 1.0 THz, and 1600 K at 1.26 THz, at an IF of 3.0 GHz. The receiver was successfully tested in the laboratory using a gas cell as a spectral line test source. It is now in use on the Smithsonian Astrophysical Observatory terahertz test telescope in northern Chile.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0018-9480 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1484  
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Author Meledin, D.; Tong, C.-Y. E.; Blundell, R.; Goltsman, G. url  doi
openurl 
  Title Measurement of intermediate frequency bandwidth of hot electron bolometer mixers at terahertz frequency range Type (up) Journal Article
  Year 2003 Publication IEEE Microw. Wireless Compon. Lett. Abbreviated Journal IEEE Microw. Wireless Compon. Lett.  
  Volume 13 Issue 11 Pages 493-495  
  Keywords waveguide NbN HEB mixers  
  Abstract We have developed a new experimental setup for measuring the IF bandwidth of superconducting hot electron bolometer mixers. In our measurement system we use a chopped hot filament as a broadband signal source, and can perform a high-speed IF scan with no loss of accuracy when compared to coherent methods. Using this technique we have measured the 3 dB IF bandwidth of hot electron bolometer mixers, designed for THz frequency operation, and made from 3-4 nm thick NbN film deposited on an MgO buffer layer over crystalline quartz.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1531-1309 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1509  
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Author Vakhtomin, Y. B.; Finkel, M. I.; Antipov, S. V.; Smirnov, K. V.; Kaurova, N. S.; Drakinskii, V. N.; Voronov, B. M.; Gol’tsman, G. N. url  openurl
  Title The gain bandwidth of mixers based on the electron heating effect in an ultrathin NbN film on a Si substrate with a buffer MgO layer Type (up) Journal Article
  Year 2003 Publication J. of communications technol. & electronics Abbreviated Journal J. of communications technol. & electronics  
  Volume 48 Issue 6 Pages 671-675  
  Keywords NbN HEB mixers  
  Abstract Measurements of the intermediate frequency band 900 GHz of mixers based on the electron heating effect (EHE) in 2-nm- and 3.5-nm-thick superconducting NbN films sputtered on MgO and Si substrates with buffer MgO layers are presented. A 2-nm-thick superconducting NbN film with a critical temperature of 9.2 K has been obtained for the first time using a buffer MgO layer.  
  Address  
  Corporate Author Thesis  
  Publisher MAIK Nauka/Interperiodica, Birmingham, AL Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1064-2269 ISBN Medium  
  Area Expedition Conference  
  Notes https://elibrary.ru/item.asp?id=17302119 (Полоса преобразования смесителей на эффекте разогрева электронов в ультратонких пленках NbN на подложках из Si с подслоем MgO) Approved no  
  Call Number Vakhtomin2003 Serial 1522  
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Author Semenov, A. D.; Hübers, H.-W.; Richter, H.; Birk, M.; Krocka, M.; Mair, U.; Smirnov, K.; Gol'tsman, G. N.; Voronov, B. M. url  doi
openurl 
  Title 2.5 THz heterodyne receiver with NbN hot-electron-bolometer mixer Type (up) Journal Article
  Year 2002 Publication Phys. C: Supercond. Abbreviated Journal Phys. C: Supercond.  
  Volume 372-376 Issue Pages 448-453  
  Keywords NbN HEB mixers, applications  
  Abstract We describe a 2.5 THz heterodyne receiver for applications in astronomy and atmospheric research. The receiver employs a superconducting NbN phonon-cooled hot-electron-bolometer mixer and an optically pumped far-infrared gas laser as local oscillator. 2200 K double sideband mixer noise temperature was measured at 2.5 THz across a 1 GHz intermediate frequency bandwidth centred at 1.5 GHz. The total conversion losses were 17 dB. The mixer response was linear at load temperatures smaller than 400 K. The receiver was tested in the laboratory environment by measuring the methanol line in emission. Observed pressure broadening confirms the true heterodyne detection regime of the mixer.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0921-4534 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1526  
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Author Cherednichenko, S.; Kroug, M.; Merkel, H.; Khosropanah, P.; Adam, A.; Kollberg, E.; Loudkov, D.; Gol'tsman, G.; Voronov, B.; Richter, H.; Huebers, H.-W. url  doi
openurl 
  Title 1.6 THz heterodyne receiver for the far infrared space telescope Type (up) Journal Article
  Year 2002 Publication Phys. C: Supercond. Abbreviated Journal Phys. C: Supercond.  
  Volume 372-376 Issue Pages 427-431  
  Keywords NbN HEB mixers, applications  
  Abstract A low noise heterodyne receiver is being developed for the terahertz range using a phonon-cooled hot-electron bolometric mixer based on 3.5 nm thick superconducting NbN film. In the 1–2 GHz intermediate frequency band the double-sideband receiver noise temperature was 450 K at 0.6 THz, 700 K at 1.6 THz and 1100 K at 2.5 THz. In the 3–8 GHz IF band the lowest receiver noise temperature was 700 K at 0.6 THz, 1500 K at 1.6 THz and 3000 K at 2.5 THz while it increased by a factor of 3 towards 8 GHz.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0921-4534 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1527  
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Author Kawamura, J.; Tong, C.-Y. E.; Blundell, R.; Papa, D. C.; Hunter, T. R.; Patt, F.; Gol’tsman, G.; Gershenzon, E. url  doi
openurl 
  Title Terahertz-frequency waveguide NbN hot-electron bolometer mixer Type (up) Journal Article
  Year 2001 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 11 Issue 1 Pages 952-954  
  Keywords NbN HEB mixers  
  Abstract We have developed a low-noise waveguide heterodyne receiver for operation near 1 THz using phonon-cooled NbN hot-electron bolometers. The mixer elements are submicron-sized microbridges of 4 nm-thick NbN film fabricated on a quartz substrate. Operating at a bath temperature of 4.2 K, the double-sideband receiver noise temperature is 760 K at 1.02 THz and 1100 K at 1.26 THz. The local oscillator is provided by solid-state sources, and power measured at the source is less than 1 /spl mu/W. The intermediate frequency bandwidth exceeds 2 GHz. The receiver was used to make the first ground-based heterodyne detection of a celestial spectroscopic line above 1 THz.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1558-2515 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1546  
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Author Hübers, H.-W.; Schubert, J.; Krabbe, A.; Birk, M.; Wagner, G.; Semenov, A.; Gol’tsman, G.; Voronov, B.; Gershenzon, E. url  doi
openurl 
  Title Parylene anti-reflection coating of a quasi-optical hot-electron-bolometric mixer at terahertz frequencies Type (up) Journal Article
  Year 2001 Publication Infrared Physics & Technology Abbreviated Journal Infrared Physics & Technology  
  Volume 42 Issue 1 Pages 41-47  
  Keywords NbN HEB mixers, anti-reflection coating  
  Abstract Parylene C was investigated as anti-reflection coating for silicon at terahertz frequencies. Measurements with a Fourier-transform spectrometer show that the transmittance of pure silicon can be improved by about 30% when applying a layer of Parylene C with a quarter wavelength optical thickness. The 10% bandwidth of this coating extends from 1.5 to 3 THz for a center frequency of 2.3–2.5 THz, where the transmittance is constant. Heterodyne measurements demonstrate that the noise temperature of a hot-electron-bolometric mixer can be reduced significantly by coating the silicon lens of the hybrid antenna with a quarter wavelength Parylene C layer. Compared to the same mixer with an uncoated lens the improvement is about 30% at a frequency of 2.5 THz.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1350-4495 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1548  
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Author Antipov, S. V.; Svechnikov, S. I.; Smirnov, K. V.; Vakhtomin, Y. B.; Finkel, M. I.; Goltsman, G. N.; Gershenzon, E. M. url  openurl
  Title Noise temperature of quasioptical NbN hot electron bolometer mixers at 900 GHz Type (up) Journal Article
  Year 2001 Publication Physics of Vibrations Abbreviated Journal Physics of Vibrations  
  Volume 9 Issue 4 Pages 242-245  
  Keywords NbN HEB mixers  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1069-1227 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1550  
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Author Svechnikov, S. I.; Antipov, S. V.; Vakhtomin, Y. B.; Goltsman, G. N.; Gershenzon, E. M.; Cherednichenko, S. I.; Kroug, M.; Kollberg, E. url  openurl
  Title Conversion and noise bandwidths of terahertz NbN hot-electron bolometer mixers Type (up) Journal Article
  Year 2001 Publication Physics of Vibrations Abbreviated Journal Physics of Vibrations  
  Volume 9 Issue 3 Pages 205-210  
  Keywords NbN HEB mixers  
  Abstract  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1069-1227 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1551  
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Author Cherednichenko, S.; Rönnung, F.; Gol'tsman, G.; Kollberg, E.; Winkler, D. url  doi
openurl 
  Title YBa2Cu3O7−δ hot-electron bolometer mixer Type (up) Journal Article
  Year 2000 Publication Phys. C: Supercond. Abbreviated Journal Phys. C: Supercond.  
  Volume 341-348 Issue Pages 2653-2654  
  Keywords YBCO HTS HEB mixers  
  Abstract We present an investigation of hot-electron bolometric mixer based on YBa2Cu3O7−δ (YBCO) superconducting thin film. Mixer conversion loss, absorbed local oscillator power and intermediate frequency bandwidth was measured at the local oscillator frequency 600 GHz. The fabrication technique for nanoscale YBCO hot-electron bolometer (HEB) mixer integrated into planar antenna structure is described.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0921-4534 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1552  
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Author Semenov, A. D.; Gol’tsman, G. N. url  doi
openurl 
  Title Nonthermal mixing mechanism in a diffusion-cooled hot-electron detector Type (up) Journal Article
  Year 2000 Publication J. Appl. Phys. Abbreviated Journal J. Appl. Phys.  
  Volume 87 Issue 1 Pages 502-510  
  Keywords NbN HEB mixers, nonthermal  
  Abstract We present an analysis of a diffusion-cooled hot-electron detector fabricated from clean superconducting material with low transition temperature. The distinctive feature of a clean material, i.e., material with large electron mean free path, is a relatively weak inelastic electron scattering that is not sufficient for the establishment of an elevated thermodynamic electron temperature when the detector is subjected to irradiation. We propose an athermal model of a diffusion-cooled detector that relies on suppression of the superconducting energy gap by the actual dynamic distribution of excess quasiparticles. The resistive state of the device is caused by the electric field penetrating into the superconducting bridge from metal contacts. The dependence of the penetration length on the energy gap delivers the detection mechanism. The sources of the electric noise are equilibrium fluctuations of the number of thermal quasiparticles and frequency dependent shot noise. Using material parameters typical for A1, we evaluate performance of the device in the heterodyne regime at terahertz frequencies. Estimates show that the mixer may have a noise temperature of a few quantum limits and a bandwidth of a few tens of GHz, while the required local oscillator power is in the μW range due to ineffective suppression of the energy gap by quasiparticles with high energies.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1558  
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Author Gerecht, E.; Musante, C. F.; Zhuang, Y.; Yngvesson, K. S.; Gol’tsman, G. N.; Voronov, B. M.; Gershenzon, E. M. url  doi
openurl 
  Title NbN hot electron bolometric mixerss—a new technology for low-noise THz receivers Type (up) Journal Article
  Year 1999 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 47 Issue 12 Pages 2519-2527  
  Keywords NbN HEB mixers  
  Abstract New advances in hot electron bolometer (HEB) mixers have recently resulted in record-low receiver noise temperatures at terahertz frequencies. We have developed quasi-optically coupled NbN HEB mixers and measured noise temperatures up to 2.24 THz, as described in this paper. We project the anticipated future performance of such receivers to have even lower noise temperature and local-oscillator power requirement as well as wider gain and noise bandwidths. We introduce a proposal for integrated focal plane arrays of HEB mixers that will further increase the detection speed of terahertz systems.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1557-9670 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1560  
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Author Rönnung, F.; Cherednichenko, S.; Winkler, D.; Gol'tsman, G. N. url  doi
openurl 
  Title A nanoscale YBCO mixer optically coupled with a bow tie antenna Type (up) Journal Article
  Year 1999 Publication Supercond. Sci. Technol. Abbreviated Journal Supercond. Sci. Technol.  
  Volume 12 Issue 11 Pages 853-855  
  Keywords YBCO HTS HEB mixers  
  Abstract The bolometric response of YBa2Cu3O7-δ(YBCO) hot-electron bolometers (HEBs) to near-infrared radiation was studied. Devices were fabricated from a 50 nm thick film and had in-plane areas of 10 × 10 µm2, 2 × 0.2 µm2, 1 × 0.2µm2 and 0.5 × 0.2 µm2. We found that nonequilibrium phonons cool down more effectively for the bolometers with smaller area. For the smallest bolometer the bolometric component in the response is 10 dB less than for the largest one.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0953-2048 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1563  
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Author Gol’tsman, G. N.; Gershenzon, E. M. url  doi
openurl 
  Title Phonon-cooled hot-electron bolometric mixer: overview of recent results Type (up) Journal Article
  Year 1999 Publication Appl. Supercond. Abbreviated Journal Appl. Supercond.  
  Volume 6 Issue 10-12 Pages 649-655  
  Keywords NbN HEB mixers  
  Abstract The paper presents an overview of recent results for NbN phonon-cooled hot electron bolometric (HEB) mixers. The noise temperature of the receivers based on both quasioptical and waveguide versions of HEB mixer has crossed the level of 1 K·GHz−1 at 430 GHz (410 K) and 600–650 GHz (480 K) and is close to this level at 820 GHz (1100 K) and 900 GHz (980 K). The gain bandwidth measured for quasioptical HEB mixer at 620 GHz reached 4 GHz and the noise temperature bandwidth was almost 8 GHz. Local oscillator power requirements are about 1 μW for mixers made by photolithography and are about 100 nW for mixers made by e-beam lithography. The studies in terahertz receivers based on HEB superconducting mixers now present a dynamic, rapidly developing field.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0964-1807 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1564  
Permanent link to this record
 
 
Author Tong, C. E.; Blundell, R.; Papa, D. C.; Smith, M.; Kawamura, J.; Gol'tsman, G.; Gershenzon, E.; Voronov, B. url  doi
openurl 
  Title An all solid-state superconducting heterodyne receiver at terahertz frequencies Type (up) Journal Article
  Year 1999 Publication IEEE Microw. Guid. Wave Lett. Abbreviated Journal IEEE Microw. Guid. Wave Lett.  
  Volume 9 Issue 9 Pages 366-368  
  Keywords waveguide NbN HEB mixers  
  Abstract A superconducting hot-electron bolometer mixer-receiver operating from 1 to 1.26 THz has been developed. This heterodyne receiver employs two solid-state local oscillators each consisting of a Gunn oscillator followed by two stages of varactor frequency multiplication. The measured receiver noise temperature is 1350 K at 1.035 THz and 2700 K at 1.26 THz. This receiver demonstrates that tunable solid-state local oscillators, supplying only a few micro-watts of output power, can be used in terahertz receiver applications.  
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  Corporate Author Thesis  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8207 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1565  
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Author Semenov, A. D.; Gol'tsman, G. N. url  doi
openurl 
  Title Non-thermal response of a diffusion-cooled hot-electron bolometer Type (up) Journal Article
  Year 1999 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 9 Issue 2 Pages 4491-4494  
  Keywords HEB mixers, non-thermal  
  Abstract We present an analysis of a diffusion-cooled hot-electron bolometer in the limiting case of a weak thermalization of non-equilibrium quasiparticles. We propose a new model relying on the non-thermal suppression of the superconducting energy gap by excess quasiparticles. Using material parameters typical for Al, we evaluate performance of the bolometer in the heterodyne regime at terahertz frequencies. Estimates show that the mixer may have quantum limited noise temperature and a few tens of GHz bandwidth, while the required local oscillator power is in the /spl mu/W range due to in-effective suppression of the energy gap by quasiparticles with high energies.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1567  
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Author Gerecht, E.; Musante, C. F.; Jian, H.; Yngvesson, K. S.; Dickinson, J.; Waldman, J.; Yagoubov, P. A.; Gol'tsman, G. N.; Voronov, B. M.; Gershenzon, E. M. url  doi
openurl 
  Title New results for NbN phonon-cooled hot electron bolometric mixers above 1 THz Type (up) Journal Article
  Year 1999 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 9 Issue 2 Pages 4217-4220  
  Keywords NbN HEB mixers  
  Abstract NbN Hot Electron Bolometric (HEB) mixers have produced promising results in terms of DSB receiver noise temperature (2800 K at 1.56 THz). The LO source for these mixers is a gas laser pumped by a CO/sub 2/ laser and the device is quasi-optically coupled through an extended hemispherical lens and a self-complementary log-periodic toothed antenna. NbN HEBs do not require submicron dimensions, can be operated comfortably at 4.2 K or higher, and require LO power of about 100-500 nW. IF noise bandwidths of 5 GHz or greater have been demonstrated. The DC bias point is also not affected by thermal radiation at 300 K. Receiver noise temperatures below 1 THz are typically 450-600 K and are expected to gradually approach these levels above 1 THz as well. NbN HEB mixers thus are rapidly approaching the type of performance required of a rugged practical receiver for astronomy and remote sensing in the THz region.  
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  Corporate Author Thesis  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1568  
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Author Yagoubov, P.; Kroug, M.; Merkel, H.; Kollberg, E.; Schubert, J.; Hubers, H.-W.; Schwaab, G.; Gol'tsman, G.; Gershenzon, E. url  doi
openurl 
  Title Heterodyne measurements of a NbN superconducting hot electron mixer at terahertz frequencies Type (up) Journal Article
  Year 1999 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 9 Issue 2 Pages 3757-3760  
  Keywords NbN HEB mixers  
  Abstract The performance of a NbN based phonon-cooled Hot Electron Bolometric (HEB) quasioptical mixer is investigated in the 0.65-3.12 THz frequency range. The device is made from a 3 nm thick NbN film on high resistivity Si and integrated with a planar spiral antenna on the same substrate. The in-plane dimensions of the bolometer strip are 0.2/spl times/2 /spl mu/m. The best results of the DSB noise temperature at 1.5 GHz IF frequency obtained with one device are: 1300 K at 650 GHz, 4700 K at 2.5 THz and 10000 K at 3.12 THz. The measurements were performed at 4.5 K ambient temperature. The amount of local oscillator (LO) power absorbed in the bolometer is about 100 nW. The mixer is linear to within 1 dB compression up to the signal level 10 dB below that of the LO. The intrinsic single sideband conversion gain measured at 650 GHz is -9 dB, the total conversion gain is -14 dB.  
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  Corporate Author Thesis  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1569  
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Author Gol'tsman, G. N. url  doi
openurl 
  Title Hot electron bolometric mixers: new terahertz technology Type (up) Journal Article
  Year 1999 Publication Infrared Physics & Technology Abbreviated Journal Infrared Physics & Technology  
  Volume 40 Issue 3 Pages 199-206  
  Keywords NbN HEB mixers  
  Abstract This paper presents an overview of recent results for NbN phonon-cooled hot electron bolometric (HEB) mixers. The noise temperature of the receivers based on both quasioptical and waveguide versions of HEB mixers has crossed the level of 1 K GHz−1 at 430 GHz (410 K), 600–650 GHz (480 K), 750 GHz (600 K), 810 GHz (780 K) and is close to that level at 1.1 THz (1250 K) and 2.5 THz (4500 K). The gain bandwidth measured for quasioptical HEB mixer at 620 GHz reached 4 GHz and the noise temperature bandwidth was almost 8 GHz. Local oscillator power requirements are about 1 μW for mixers made by photolithography and about 100 nW for mixers made by e-beam lithography. A waveguide version of 800 GHz receiver was installed at the Submillimeter Telescope Observatory on Mt. Graham, AZ, to conduct astronomical observations of known submillimeter lines (CO, J=7→6, CI, J=2→1). It was proved that the receiver works as a practical instrument.  
  Address  
  Corporate Author Thesis  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1350-4495 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1570  
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Author Gousev, Y. P.; Semenov, A. D.; Goghidze, I. G.; Pechen, E. V.; Varlashkin, A. V.; Gol'tsman, G. N.; Gershenzon, E. M.; Renk, K. F. url  doi
openurl 
  Title Current dependent noise in a YBa2Cu3O7-δ hot-electron bolometer Type (up) Journal Article
  Year 1997 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 7 Issue 2 Pages 3556-3559  
  Keywords YBCO HTS HEB mixers  
  Abstract We investigated the output noise of a YBa2Cu3O7-δ (YBCO) superconducting hot-electron bolometer (HEB) in a large frequency range (10 kHz to 8 GHz); the bolometer either consisted of a structured 50 nm thick YBCO film on LaAlO/sub 3/ or a 30 nm thick film on a MgO substrate. We found that flicker noise dominated at low frequencies (below 1 MHz), while at higher frequencies Johnson noise and a current dependent noise were the main noise sources.  
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  Corporate Author Thesis  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1592  
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Author Semenov, A. D.; Gousev, Y. P.; Renk, K. F.; Voronov, B. M.; Gol'tsman, G. N.; Gershenzon, E. M.; Schwaab, G.W.; Feinaugle, R. url  doi
openurl 
  Title Noise characteristics of a NbN hot-electron mixer at 2.5 THz Type (up) Journal Article
  Year 1997 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 7 Issue 2 Pages 3572-3575  
  Keywords NbN HEB mixers  
  Abstract The noise temperature of a NbN phonon cooled hot-electron mixer has been measured at a frequency of 2.5 THz for various operating conditions. We obtained for optimal operation a double sideband mixer noise temperature of /spl ap/14000 K and a system conversion loss of /spl ap/23 dB at intermediate frequencies up to 1 GHz. The dependences of the mixer noise temperature on the bias voltage, local oscillator power, and intermediate frequency were consistent with the phenomenological description based on the effective temperature approximation.  
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  Corporate Author Thesis  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1594  
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Author Svechnikov, S. I.; Okunev, O. V.; Yagoubov, P. A.; Gol'tsman, G. N.; Voronov, B. M.; Cherednichenko, S. I.; Gershenzon, E. M.; Gerecht, E.; Musante, C. F.; Wang, Z.; Yngvesson, K. S. url  doi
openurl 
  Title 2.5 THz NbN hot electron mixer with integrated tapered slot antenna Type (up) Journal Article
  Year 1997 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 7 Issue 2 Pages 3548-3551  
  Keywords NbN HEB mixers  
  Abstract A Hot Electron Bolometer (HEB) mixer for 2.5 THz utilizing a NbN thin film device, integrated with a Broken Linearly Tapered Slot Antenna (BLTSA), has been fabricated and is presently being tested. The NbN HEB device and the antenna were fabricated on a SiO2membrane. A 0.5 micrometer thick SiO2layer was grown by rf magnetron reactive sputtering on a GaAs wafer. The HEB device (phonon-cooled type) was produced as several parallel strips, 1 micrometer wide, from an ultrathin NbN film 4-7 nm thick, that was deposited onto the SiO2layer by dc magnetron reactive sputtering. The BLTSA was photoetched in a multilayer Ti-Au metallization. In order to strengthen the membrane, the front-side of the wafer was coated with a 5 micrometer thick polyimide layer just before the membrane formation. The last operation was anisotropic etching of the GaAs in a mixture of HNO3and H2O2.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1595  
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Author Svechnikov, S.; Gol'tsman, G.; Voronov, B.; Yagoubov, P.; Cherednichenko, S.; Gershenzon, E.; Belitsky, V.; Ekstrom, H.; Kollberg, E.; Semenov, A.; Gousev, Y.; Renk, K. url  doi
openurl 
  Title Spiral antenna NbN hot-electron bolometer mixer at submm frequencies Type (up) Journal Article
  Year 1997 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 7 Issue 2 Pages 3395-3398  
  Keywords NbN HEB mixers  
  Abstract We have studied the phonon-cooled hot-electron bolometer (HEB) as a quasioptical mixer based on a spiral antenna designed for the 0.3-1 THz frequency band and fabricated on sapphire and high resistivity silicon substrates. HEB devices were produced from superconducting 3.5-5 nm thick NbN films with a critical temperature 10-12 K and a critical current density of approximately 10/sup 7/ A/cm/sup 2/ at 4.2 K. For these devices we reached a DSB receiver noise temperature below 1500 K, a total conversion loss of L/sub t/=16 dB in the 500-700 GHz frequency range, an IF bandwidth of 3-4 GHz and an optimal LO absorbed power of /spl sime/4 /spl mu/W. We experimentally analyzed various contributions to the conversion loss and obtained an RF coupling factor of about 5 dB, internal mixer loss of 10 dB and IF mismatch of 1 dB.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1597  
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Author Kawamura, J.; Blundell, R.; Tong, C.-yu E.; Gol’tsman, G.; Gershenzon, E.; Voronov, B.; Cherednichenko, S. url  doi
openurl 
  Title Low noise NbN lattice-cooled superconducting hot-electron bolometric mixers at submillimeter wavelengths Type (up) Journal Article
  Year 1997 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.  
  Volume 70 Issue 12 Pages 1619-1621  
  Keywords NbN HEB mixers  
  Abstract Lattice-cooled superconducting hot-electron bolometric mixers are used in a submillimeter-wave waveguide heterodyne receiver. The mixer elements are niobium nitride film with 3.5 nm thickness and ∼10 μm2 area. The local oscillator power for optimal performance is estimated to be 0.5 μW, and the instantaneous bandwidth is 2.2 GHz. At an intermediate frequency centered at 1.4 GHz with 200 MHz bandwidth, the double sideband receiver noise temperature is 410 K at 430 GHz. The receiver has been used to detect molecular line emission in a laboratory gas cell.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-6951 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1599  
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Author Kawamura, J.; Blundell, R.; Tong, C.‐yu E.; Gol’tsman, G.; Gershenzon, E.; Voronov, B. url  doi
openurl 
  Title Performance of NbN lattice‐cooled hot‐electron bolometric mixers Type (up) Journal Article
  Year 1996 Publication J. Appl. Phys. Abbreviated Journal J. Appl. Phys.  
  Volume 80 Issue 7 Pages 4232-4234  
  Keywords NbN HEB mixers  
  Abstract The heterodyne performance of lattice‐cooled hot‐electron bolometric mixers is measured at 200 GHz. Superconducting thin‐film niobium nitride strips with ∼5 nm thickness are used as waveguide mixer elements. A double‐sideband receiver noise temperature of 750 K at 244 GHz is measured at an intermediate frequency centered at 1.5 GHz with 500 MHz bandwidth and with 4.2 K device temperature. The instantaneous bandwidth for this mixer is 1.6 GHz. The local oscillator power required by the mixer is about 0.5 μW. The mixer is linear to within 1 dB up to an input power level 6 dB below the local oscillator power. A receiver incorporating a hot‐electron bolometric mixer was used to detect molecular line emission in a laboratory gascell. This experiment unambiguously confirms that the receiver noise temperature determined from Y‐factor measurements reflects the true heterodyne sensitivity.  
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  Corporate Author Thesis  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0021-8979 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1607  
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Author Semenov, A. D.; Gousev, Y. P.; Nebosis, R. S.; Renk, K. F.; Yagoubov, P.; Voronov, B. M.; Gol’tsman, G. N.; Syomash, V. D.; Gershenzon, E. M. url  doi
openurl 
  Title Heterodyne detection of THz radiation with a superconducting hot‐electron bolometer mixer Type (up) Journal Article
  Year 1996 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.  
  Volume 69 Issue 2 Pages 260-262  
  Keywords NbN HEB mixers  
  Abstract We report on the use of a superconducting hot‐electron bolometer mixer for heterodyne detection of terahertz radiation. Radiation with a wavelength of 119 μm was coupled to the mixer, a NbN microbridge, by a hybrid quasioptical antenna consisting of an extended hyperhemispherical lens and a planar logarithmic spiral antenna. We found, at an intermediate frequency of 1.5 GHz, a system double side band noise temperature of ≊40 000 K and conversion losses of 25 dB. We also discuss the possibilities of further improvement of the mixer performance.  
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  Corporate Author Thesis  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-6951 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1610  
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Author Trifonov, V. A.; Karasik, B. S.; Zorin, M. A.; Gol’tsman, G. N.; Gershenzon, E. M.; Lindgren, M.; Danerud, M.; Winkler, D. url  doi
openurl 
  Title 9.6 μm wavelength mixing in a patterned YBa2Cu3O7‐δ thin film Type (up) Journal Article
  Year 1996 Publication Appl. Phys. Lett. Abbreviated Journal Appl. Phys. Lett.  
  Volume 68 Issue 10 Pages 1418-1420  
  Keywords YBCO HTS HEB mixers  
  Abstract Hot‐electron bolometric (HEB) mixing of 9.6 μm infrared radiation from two lasers in high‐quality YBa2Cu3O7−δ (YBCO) patterned thin film has been demonstrated. A heterodyne measurement showed an intermediate frequency (IF) bandwidth of 18 GHz, limited by our measurement system. An intrinsic limit of 100 GHz is predicted. Between 0.1 and 1 GHz intermediate frequency, temperature fluctuations with an equivalent output noise temperature Tfl up to ∼150 K, contributed to the mixer noise while Johnson noise dominated above 1 GHz. The overall conversion loss at 77 K at low intermediate frequencies was measured to be ∼25 dB, of which 13 dB was due to the coupling loss. The HEB mixer is very promising for use in heterodyne receivers within the whole infrared range.  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0003-6951 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1613  
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Author Zorin, M.; Gol'tsman, G.N.; Karasik, B.S.; Elantev, A.I.; Gershenzon, E.M.; Lindgren, M.; Danerud, M.; Winkler, D. url  doi
openurl 
  Title Optical mixing in thin YBa2Cu3O7-x films Type (up) Journal Article
  Year 1995 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 5 Issue 2 Pages 2431-2434  
  Keywords YBCO HTS HEB mixers  
  Abstract High quality, j/sub c/ (77 K)>10/sup 6/ A/cm/sup 2/, epitaxial YBa2Cu3O7-x films of 50 nm thickness were patterned into ten parallel 1 /spl mu/m wide strips. The film structure was coupled to a single-mode fiber. Mixer response was obtained at 0.78 /spl mu/m using laser frequency modulation and an optical delay line. Using two semiconductor lasers at 1.55 /spl mu/m wavelength the beating signal was used to measure the photoresponse up to 18 GHz. Nonequilibrium photoresponse in the resistive state of the superconductor was observed. Bolometric response dominates up to 3 GHz, after which the nonequilibrium response is constant up to the frequency limit of our registration system. Using an electron heating model the influence of different thermal processes on the conversion loss has been analyzed. Ways of increasing the sensitivity are also discussed.  
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  Corporate Author Thesis  
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  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1619  
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Author Karasik, B. S.; Gol'tsman, G. N.; Voronov, B. M.; Svechnikov, S. I.; Gershenzon, E. M.; Ekstrom, H.; Jacobsson, S.; Kollberg, E.; Yngvesson, K. S. url  doi
openurl 
  Title Hot electron quasioptical NbN superconducting mixer Type (up) Journal Article
  Year 1995 Publication IEEE Trans. Appl. Supercond. Abbreviated Journal IEEE Trans. Appl. Supercond.  
  Volume 5 Issue 2 Pages 2232-2235  
  Keywords NbN HEB mixers  
  Abstract Hot electron superconductor mixer devices made of thin NbN films on SiO/sub 2/-Si/sub 3/N/sub 4/-Si membrane have been fabricated for 300-350 GHz operation. The device consists of 5-10 parallel strips each 5 /spl mu/m long by 1 /spl mu/m wide which are coupled to a tapered slot-line antenna. The I-V characteristics and position of optimum bias point were studied in the temperature range 4.5-8 K. The performance of the mixer at higher temperatures is closer to that predicted by theory for uniform electron heating. The intermediate frequency bandwidth versus bias has also been investigated. At the operating temperature 4.2 K a bandwidth as wide as 0.8 GHz has been measured for a mixer made of 6 nm thick film. The bandwidth tends to increase with operating temperature. The performance of the NbN mixer is expected to be better for higher frequencies where the absorption of radiation should be more uniform.  
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  Corporate Author Thesis  
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  Language Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1051-8223 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number Serial 1622  
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Author Pentin, Ivan; Finkel, Matvey; Maslennikov, Sergey; Vakhtomin, Yuri; Smirnov, Konstantin; Kaurova, Nataliya; Goltsman, Gregory url  openurl
  Title Superconducting hot-electron-bolometer mixers for the mid-IR Type (up) Journal Article
  Year 2017 Publication Rus. J. Radio Electron. Abbreviated Journal Rus. J. Radio Electron.  
  Volume Issue 10 Pages  
  Keywords IR NbN HEB mixers  
  Abstract The work presents the result of development of the NbN superconducting hot-electron-bolometer (HEB) mixer. The sensitive element of the mixer is directly coupled to mid-IR radiation, and doesn’t have planar metallic antenna. Investigations of noise characteristics of NbN HEB mixer were performed at the frequency 28.4 THz (λ = 10.6 µm) by using gas-discharge CW CO2-laser without consideration of optical and electrical losses in the heterodyne receiver. The noise temperature of NbN HEB mixer with the size of the sensitive element 10 µm × 10 µm was 2320 K (~ 1.5hν/kB) at the heterodyne frequency of 28.4 THz. The noise temperature was determined by measuring the Y-factor taking into account the term which describes fluctuations of zero-point oscillations in accordance with the fluctuation-dissipation theorem of Calle-Welton. Isothermal method was used to estimate the absorbed heterodyne radiation power which was 9 µW at the optimal operating point for the minimum noise temperature of NbN HEB mixer.  
  Address  
  Corporate Author Thesis  
  Publisher Place of Publication Editor  
  Language Russian Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1684-1719 ISBN Medium  
  Area Expedition Conference  
  Notes http://jre.cplire.ru/jre/oct17/9/abstract.html (Russian) Гетеродинный приемник со сверхпроводниковым смесителем на эффекте электронного разогрева для среднего инфракрасного диапазона Approved no  
  Call Number Serial 1747  
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