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| Author | Rönnung, F.; Cherednichenko, S.; Winkler, D.; Gol'tsman, G. N. | ||||
Title  |
A nanoscale YBCO mixer optically coupled with a bow tie antenna | Type | 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. | ||||
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| 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 | Tong, C.-Y. E.; Trifonov, A.; Shurakov, A.; Blundell, R.; Gol’tsman, G. | ||||
| Title |
A microwave-operated hot-electron-bolometric power detector for terahertz radiation | Type | 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 | |||
| Permanent link to this record | |||||
| Author | Shurakov, A.; Tong, Cheuk-yu E.; Grimes, P.; Blundell, R.; Golt'sman, G. | ||||
| Title |
A microwave reflection readout scheme for hot electron bolometric direct detector | Type | Journal Article | ||
| Year | 2015 | Publication | IEEE Trans. THz Sci. Technol. | Abbreviated Journal | IEEE Trans. THz Sci. Technol. |
| Volume | 5 | Issue | Pages | 81-84 | |
| Keywords | HEB detectors | ||||
| Abstract | In this paper, we propose and present data from a fast THz detector based on the repurpose of hot electron bolometer mixers (HEB) fabricated from superconducting NbN thinfilm. This detector is essentially a traditional NbN bolometer element that operates under the influence of a microwave pump. The in-jected microwave power serves the dual purpose of enhancing the detector sensitivity and reading out the impedance changes of the device in response to incidentTHz radiation. We have measured an optical Noise Equivalent Power of 4 pW/ Hz for our detector at a bath temperature of 4.2 K. The measurement frequency was 0.83 THz and the modulation frequency was 1.48 kHz. The readout scheme is versatile and facilitates both high-speed operation as well as multi-pixel applications. |
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| Notes | Approved | no | |||
| Call Number | RPLAB @ atomics90 @ | Serial | 950 | ||
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| Author | Shurakov, Alexander; Tong, Cheuk-yu E.; Blundell, Raymond; Gol’tsman, Gregory | ||||
| Title |
A microwave pumped HEB direct detector using a homodyne readout scheme | Type | Abstract | ||
| Year | 2014 | Publication | Proc. 25th Int. Symp. Space Terahertz Technol. | Abbreviated Journal | Proc. 25th Int. Symp. Space Terahertz Technol. |
| Volume | Issue | Pages | 129 | ||
| Keywords | waveguide NbN HEB detector, NEP | ||||
| Abstract | We report the results of our study on the noise performance of a fast THz detector based on the repurpose of hot electron bolometer mixer (HEB). Instead of operating with an elevated bath temperature, microwave power is injected into the HEB device, which enhances the sensitivity of the detector and at the same time provide a mechanism for reading out impedance changes of the device induced by the modulated incident THz radiation [1]. We have demonstrated an improvement of the detector’s optical noise equivalent power (NEP). Furthermore, by introducing a homodyne readout scheme based on a room temperature microwave mixer, the dynamic range of the detector is increased. The HEB devices used in this work were made of 4 nm thick NbN film. The detector chips were installed into a waveguide mixer block fitted with a corrugated horn, mounted on the cold plate of a liquid helium cryostat. The HEBs were operated at a bath temperature of 4.2 K. The signal beam was terminated on black bodies at ambient and liquid nitrogen temperatures. A chopper wheel placed in front of the cryostat window operating at a frequency of 1.48 kHz modulated the input load temperature of the detector. A cold mesh filter, centered at 830 GHz, was used to define the input signal power bandwidth. Microwave was injected through a broadband directional coupler inside the cryostat. Our experiments were mostly conducted at a pump frequency of 1.5 GHz. The reflected microwave power from the HEB device was fed into a cryogenic low noise amplifier (LNA). The output of the LNA was connected to the RF input port of a room temperature microwave mixer, which beat the reflected signal from the HEB using a copy of the original 1.5 GHz injection signal in a homodyne demodulation scheme. The amplitude of the detected power was measured by a lock-in amplifier, which was synchronized to the chopper frequency. Preliminary results yield an optical NEP of ~1 pW/ Hz 1/2 which corresponds to an improvement of a factor of 3 compared to [1], driven mainly by a lowering of the system noise floor. The dynamic range was also increased by similar amount. References 1. A. Shurakov et al. “A Microwave Pumped Hot Electron Bolometric Direct Detector,” submitted on Oct 18, 2013 to Appl. Phys. Let. | ||||
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| Notes | Approved | no | |||
| Call Number | Serial | 1365 | |||
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| Author | Phillips, T. G.; Jefferts, K. B. | ||||
| Title |
A low temperature bolometer heterodyne receiver for Millimeter wave astronomy | Type | Journal Article | ||
| Year | 1973 | Publication | Rev. Sci. Instrum. | Abbreviated Journal | Rev. Sci. Instrum. |
| Volume | 44 | Issue | 8 | Pages | 1009-1014 |
| Keywords | InSb HEB mixer | ||||
| Abstract | Liquid helium cooled InSb hot electronbolometers are used in a balanced mixer configuration as detectors for an imagelessmicrowave receiver. The system is designed for mounting at the prime focus of the National Radio Astronomy Observatory (NRAO) 11 m antenna at Kitt Peak, Arizona, and is suitable for the study of rotational line spectra of interstellar gas molecules. Currently the operating frequency is in the 90–140 GHz band where the double sideband system noise temperature is 250 K. | ||||
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| Notes | Recommended by Klapwijk | Approved | no | ||
| Call Number | Serial | 927 | |||
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| Author | Blundell, R.; Kawamura, J. H.; Tong, C. E.; Papa, D. C.; Hunter, T. R.; Gol’tsman, G. N.; Cherednichenko, S. I.; Voronov, B. M.; Gershenzon, E. M. | ||||
| Title |
A hot-electron bolometer mixer receiver for the 680-830 GHz frequency range | Type | Conference Article | ||
| Year | 1998 | Publication | Proc. 6-th Int. Conf. Terahertz Electron. | Abbreviated Journal | Proc. 6-th Int. Conf. Terahertz Electron. |
| Volume | Issue | Pages | 18-20 | ||
| Keywords | NbN HEB mixers | ||||
| Abstract | We describe a heterodyne receiver designed to operate in the partially transparent atmospheric windows centered on 680 and 830 GHz. The receiver incorporates a niobium nitride thin film, cooled to 4.2 K, as the phonon-cooled hot-electron mixer element. The double sideband receiver noise, measured over the frequency range 680-830 GHz, is typically 700-1300 K. The instantaneous output bandwidth of the receiver is 600 MHz. This receiver has recently been used at the SubMillimeter Telescope, jointly operated by the Steward Observatory and the Max Planck Institute for Radioastronomy, for observations of the neutral carbon and CO spectral lines at 810 GHz and at 806 and 691 GHz respectively. Laboratory measurements on a second mixer in the same test receiver have yielded extended high frequency performance to 1 THz. | ||||
| Address | Leeds, UK | ||||
| Corporate Author | Thesis | ||||
| Publisher | IEEE | Place of Publication | Editor | ||
| Language | Summary Language | Original Title | |||
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| ISSN | ISBN | 0-7803-4903-2 | Medium | ||
| Area | Expedition | Conference | IEEE Sixth International Conference on Terahertz Electronics Proceedings. THZ 98. (Cat. No.98EX171) | ||
| Notes | Approved | no | |||
| Call Number | Serial | 1581 | |||
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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. | ||||
| Title |
A HIFI preview of warm molecular gas around χ Cygni: first detection of H2O emission toward an S-type AGB star | Type | 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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| Notes | Approved | no | |||
| Call Number | Serial | 1096 | |||
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| Author | Pineda, J. L.; Langer, W. D.; Velusamy, T.; Goldsmith, P. F. | ||||
| Title |
A Herschel [C ii] Galactic plane survey. I. The global distribution of ISM gas components | Type | 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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| Notes | Approved | no | |||
| Call Number | Serial | 1100 | |||
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| Author | Khosropanah, P.; Merkel, H.; Yngvesson, S.; Adam, A.; Cherednichenko, S.; Kollberg, E. | ||||
| Title |
A distributed device model for phonon-cooled HEB mixers predicting IV characteristics, gain, noise and IF bandwidth | Type | Conference Article | ||
| Year | 2000 | Publication | Proc. 11th Int. Symp. Space Terahertz Technol. | Abbreviated Journal | |
| Volume | Issue | Pages | 474-488 | ||
| Keywords | HEB mixer numerical model, diffusion cooling channel, diffusion channel, distributed HEB model, distributed model | ||||
| Abstract | A distributed model for phonon-cooled superconductor hot electron bolometer (HEB) mixers is given, which is based on solving the one-dimensional heat balance equation for the electron temperature profile along the superconductor strip. In this model it is assumed that the LO power is absorbed uniformly along the bridge but the DC power absorption depends on the local resistivity and is thus not uniform. The electron temperature dependence of the resistivity is assumed to be continuous and has a Fermi form. These assumptions are used in setting up the non-linear heat balance equation, which is solved numerically for the electron temperature profile along the bolometer strip. Based on this profile the resistance of the device and the IV curves are calculated. The IV curves are in excellent agreement with measurement results. Using a small signal model the conversion gain of the mixer is obtained. The expressions for Johnson noise and thermal fluctuation noise are derived. The calculated results are in close agreement with measurements, provided that one of the parameters used is adjusted. | ||||
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| Publisher | Place of Publication | University of Michigan, Ann Arbor, MI USA | Editor | ||
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| Notes | Approved | no | |||
| Call Number | Serial | 893 | |||
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| Author | Tong, C. Edward; Trifonov, Andrey; Blundell, Raymond; Shurakov, Alexander; Gol’tsman, Gregory | ||||
| Title |
A digital terahertz power meter based on an NbN thin film | Type | Abstract | ||
| Year | 2014 | Publication | Proc. 25th Int. Symp. Space Terahertz Technol. | Abbreviated Journal | Proc. 25th Int. Symp. Space Terahertz Technol. |
| Volume | Issue | Pages | 170 | ||
| Keywords | waveguide NbN HEB mixers | ||||
| Abstract | We have further studied the effect of subjecting a superconducting Hot Electron Bolometer (HEB) element made from an NbN thin film to microwave radiation. Since the photon energy is weak, the microwave radiation does not simply heat the film, but generates a bi-static state, switching between the superconducting and normal states, upon the application of a small voltage bias. Indeed, a relaxation oscillation of a few MHz has previously been reported in this regime [1]. Switching between the superconducting and normal states modulates the reflected microwave pump power from the device. A simple homodyne setup readily recovers the spontaneous switching waveform in the time domain. The switching frequency is a function of both the bias voltage (DC heating) and the applied microwave power. In this work, we use a 0.8 THz HEB waveguide mixer for the purpose of demonstration. The applied microwave pump, coupled through a directional coupler, is at 1 GHz. Since the pump power is of the order of a few μW, a room temperature amplifier is sufficient to amplify the reflected pump power from the HEB mixer, which beats with the microwave source in a homodyne set-up. After further amplification, the switching waveform is passed onto a frequency counter. The typical frequency of the switching pulses is 3-5 MHz. It is found that the digital frequency count increases with higher microwave pump power. When the HEB mixer is subjected to additional optical power at 0.8 THz, the frequency count also increases. When we vary the incident optical power by using a wire grid attenuator, a linear relationship is observed between the frequency count and the applied optical power, over at least an order of magnitude of power. This phenomenon can be exploited to develop a digital power meter, using a very simple electronics setup. Further experiments are under way to determine the range of linearity and the accuracy of calibration transfer from the microwave to the THz regime. References 1. Y. Zhuang, and S. Yngvesson, “Detection and interpretation of bistatic effects in NbN HEB devices,” Proc. 13 th Int. Symp. Space THz Tech., 2002, pp. 463–472. | ||||
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| Notes | Approved | no | |||
| Call Number | Serial | 1366 | |||
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