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Author Hübers, H.-W.; Semenov, A.; Richter, H.; Birk, Manfred; Krocka, Michael; Mair, Ulrich; Smirnov, K.; Gol'tsman, G.; Voronov, B.
Title Terahertz heterodyne receiver with a hot-electron bolometer mixer Type Conference Article
Year 2002 Publication Proc. Far-IR, Sub-mm, and mm Detector Technology Workshop Abbreviated Journal Proc. Far-IR, Sub-mm, and mm Detector Technology Workshop
Volume Issue Pages
Keywords NbN HEB mixers
Abstract (up) During the past decade major advances have been made regarding low noise mixers for terahertz (THz) heterodyne receivers. State of the art hot-electron-bolometer (HEB) mixers have noise temperatures close to the quantum limit and require less than a µW power from the local oscillator (LO). The technology is now at a point where the performance of a practical receiver employing such mixer, rather than the figures of merit of the mixer itself, are of major concern. We have incorporated a phonon-cooled NbN HEB mixer in a 2.5 THz heterodyne receiver and investigated the performance of the receiver. This yields important information for the development of heterodyne receivers such as GREAT (German receiver for astronomy at THz frequencies aboard SOFIA)[1] and TELIS (Terahertz limb sounder), a balloon borne heterodyne receiver for atmospheric research [2]. Both are currently under development at DLR.
Address Monterey, CA, USA
Corporate Author Thesis
Publisher Place of Publication Editor Wold, J.; Davidson, J.
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Area Expedition Conference
Notes 4 pages; Unconfirmed but cited in https://kups.ub.uni-koeln.de/1622/1/bedorf.pdf; There is a Program of the Workshop: https://www.yumpu.com/en/document/view/7411055/far-ir-submm-mm-detector-technology-workshop-sofia-usra (there is no title of this article in the Program); There is also identical publication in Proc. ISSTT (Serial: 332, “A broadband terahertz heterodyne receiver with an NbN HEB mixer”). Approved no
Call Number Serial 1829
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Author Decin, L.; Justtanont, K.; De Beck, E.; Lombaert, R.; de Koter, A.; Waters, L. B. F. M.; Marston, A. P.; Teyssier, D.; Schöier, F. L.; Bujarrabal, V.; Alcolea, J.; Cernicharo, J.; Dominik, C.; Melnick, G.; Menten, K.; Neufeld, D. A.; Olofsson, H.; Planesas, P.; Schmidt, M.; Szczerba, R.; de Graauw, T.; Helmich, F.; Roelfsema, P.; Dieleman, P.; Morris, P.; Gallego, J. D.; Díez-González, M. C.; Caux, E.
Title Water content and wind acceleration in the envelope around the oxygen-rich AGB star IK Tauri as seen by Herschel/HIFI Type Journal Article
Year 2010 Publication Astron. Astrophys. Abbreviated Journal
Volume 521 Issue Pages L4
Keywords HEB mixer applications, HIFI, Herschel, line: profiles / radiative transfer / instrumentation: spectrographs / stars: AGB and post-AGB / circumstellar matter / submillimeter: stars
Abstract (up) During their asymptotic giant branch evolution, low-mass stars lose a significant fraction of their mass through an intense wind, enriching the interstellar medium with products of nucleosynthesis. We observed the nearby oxygen-rich asymptotic giant branch star IK Tau using the high-resolution HIFI spectrometer onboard Herschel. We report on the first detection of H216O and the rarer isotopologues H217O and H218O in both the ortho and para states. We deduce a total water content (relative to molecular hydrogen) of $6.6 \times 10^{-5}$, and an ortho-to-para ratio of 3:1. These results are consistent with the formation of H2O in thermodynamical chemical equilibrium at photospheric temperatures, and does not require pulsationally induced non-equilibrium chemistry, vaporization of icy bodies or grain surface reactions. High-excitation lines of 12CO, 13CO, 28SiO, 29SiO, 30SiO, HCN, and SO have also been detected. From the observed line widths, the acceleration region in the inner wind zone can be characterized, and we show that the wind acceleration is slower than hitherto anticipated.
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Notes Approved no
Call Number Serial 1090
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Author Maslennikov, S. N.; Morozov, D. V.; Ozhegov, R. V.; Smirnov, K. V.; Okunev, O. V.; Gol’tsman, G. N.
Title Imaging system for submillimeter wave range based on AlGaAs/GaAs hot electron bolometer mixers Type Conference Article
Year 2004 Publication Proc. 5-th MSMW Abbreviated Journal Proc. 5-th MSMW
Volume 2 Issue Pages 558-560
Keywords AlGaAs/GaAs HEB mixers
Abstract (up) Electromagnetic radiation of the submillimeter (SMM) range is dispersed and absorbed significantly less than infrared (IR) radiation when passing through different objects. That is the reason for the development of an SMM imaging system. In this paper, we discuss the design of an SMM heterodyne imager, based on a matrix of AlGaAs/GaAs heterostructure hot electron bolometer mixers (HEB) with relatively high (about 77 K) operating temperature. The predicted double side band (DSB) noise temperature is about 1000 K and optimal local oscillator (LO) power is about 1 /spl mu/W for such mixers, which seems to be quite prospective for an SMM heterodyne imager.
Address Kharkov, Ukraine
Corporate Author Thesis
Publisher Place of Publication Editor
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ISSN ISBN Medium
Area Expedition Conference The Fifth International Kharkov Symposium on Physics and Engineering of Microwaves, Millimeter, and Submillimeter Waves (IEEE Cat. No.04EX828)
Notes Approved no
Call Number Serial 1487
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Author Danerud, M.; Winkler, D.; Lindgren, M.; Zorin, M.; Trifonov, V.; Karasik, B. S.; Gol’tsman, G. N.; Gershenzon, E. M.
Title Nonequilibrium and bolometric photoresponse in patterned YBa2Cu3O7−δ thin films Type Journal Article
Year 1994 Publication J. Appl. Phys. Abbreviated Journal J. Appl. Phys.
Volume 76 Issue 3 Pages 1902-1909
Keywords YBCO HTS HEB detector, nonequilibrium response
Abstract (up) Epitaxial laser deposited YBa2Cu3O7−δ films of ∼50 nm thickness were patterned into detectors consisting of ten parallel 1 μm wide strips in order to study nonequilibrium and bolometric effects. Typically, the patterned samples had critical temperatures around 86 K, transition widths around 2 K and critical current densities above 1×106A/cm2 at 77 K. Pulsed laser measurements at 0.8 μm wavelength (17 ps full width at half maximum) showed a ∼30 ps response, attributed to electron heating, followed by a slower bolometric decay. Amplitude modulation in the band fmod=100 kHz–10 GHz of a laser with wavelength λ=0.8 μm showed two different thermal relaxations in the photoresponse. Phonon escape from the film (∼3 ns) is the limiting process, followed by heat diffusion in the substrate. Similar relaxations were also seen for λ=10.6 μm. The photoresponse measurements were made with the film in the resistive state and extended into the normal state. These states were created by supercritical bias currents. Measurements between 75 and 95 K (i.e., from below to above Tc) showed that the photoresponse was proportional to dR/dT for fmod=1 MHz and 4 GHz. The fast response is limited by the electron‐phonon scattering time, estimated to 1.8 ps from experimental data. The responsivity both at 0.8 and 10.6 μm wavelength was ∼1.2 V/W at fmod=1 GHz and the noise equivalent power was calculated to 1.5×10−9 WHz−1/2 for the fast response.
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 1637
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Author Leisawitz, David T.; Danchi, William C.; Dipirro, Michael J.; Feinberg, Lee D.; Gezari, Daniel Y.; Hagopian, Mike; Langer, William D.; Mather, John C.; Moseley, Jr. Samuel H.; Shao, Michael; Silverberg, Robert F.; Staguhn, Johannes G.; Swain, Mark R.; Yorke, Harold W.; Zhang, Xiaolei
Title Scientific motivation and technology requirements for the SPIRIT and SPECS far-infrared/submillimeter space interferometers Type Conference Article
Year 2000 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 4013 Issue Pages 36-46
Keywords HEB applications
Abstract (up) Far infrared interferometers in space would enable extraordinary measurements of the early universe, the formation of galaxies, stars, and planets, and would have great discovery potential. Since half the luminosity of the universe and 98% of the photons released since the Big Bang are now observable at far IR wavelengths (40 – 500 micrometers ), and the Earth's atmosphere prevents sensitive observations from the ground, this is one of the last unexplored frontiers of space astronomy. We present the engineering and technology requirements that stem from a set of compelling scientific goals and discuss possible configurations for two proposed NASA missions, the Space Infrared Interferometric Telescope and the Submillimeter Probe of the Evolution of Cosmic Structure.
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Publisher Place of Publication Editor
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Area Expedition Conference
Notes Approved no
Call Number Serial 909
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Author Voronov, B. M.; Gershenzon, E. M.; Gol'tsman, G. N.; Gogidze, I. G.; Gusev, Yu. P.; Zorin, M. A.; Sejdman, L. A.; Semenov, A. D.
Title Picosecond range detector base on superconducting niobium nitride film sensitive to radiation in spectral range from millimeter waves up to visible light Type Journal Article
Year 1992 Publication Sverkhprovodimost': Fizika, Khimiya, Tekhnika Abbreviated Journal Sverkhprovodimost': Fizika, Khimiya, Tekhnika
Volume 5 Issue 5 Pages 955-960
Keywords NbN HEB detectors
Abstract (up) Fast-operating picosecond detector of electromagnetical radiation is developed on the basis of fine superconducting film of niobium nitride with high sensitivity within spectral range from millimetric waves up to visible light. Detector sensitive element represents structure covering narrow parallel strips with micron sizes included in the rupture of microstrip line. Detecting ability of the detector and time constant measured using amplitude-simulated radiation of reverse wave tubes and pulse radiation of picosecond gas and solid-body lasers, constitute D*≅1010 W-1·cm·Hz-1/2 and τ≤5 ps respectively, at 10 K temperature. The expected value of time constant of the detector at 10 K obtained via extrapolation of directly measured dependence that is, τ ∝ τ-1, constitutes 20 ps. Experimental data demonstrate that detection mechanism is linked with electron heating effect.
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 0131-5366 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1670
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Author Gershenzon, E. M.; Gershenzon, M. E.; Gol'tsman, G. N.; Karasik, B. S.; Semenov, A. D.; Sergeev, A. V.
Title Light-induced heating of electrons and the time of the inelastic electron-phonon scattering in the YBaCuO compound Type Journal Article
Year 1987 Publication JETP Lett. Abbreviated Journal JETP Lett.
Volume 46 Issue 6 Pages 285-287
Keywords YBCO HTS HEB
Abstract (up) For the first time, measurements have been made on the electron energy relaxation time due to the electron--phonon interaction in films of the YBaCuO superconductor. The results indicate a significant intensification of the electron--phonon interaction in this compound as compared with normal superconducting metals.
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Notes Approved no
Call Number Serial 1706
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Author Karasik, Boris S.; Cantor, Robin
Title Optical NEP in hot-electron nanobolometers Type Journal Article
Year 2010 Publication Abbreviated Journal
Volume Issue Pages 1-7
Keywords HEB, Ti, NEP, femtowatt, SAFARI, SPICA, 650 GHz, 0.65 THz, 460 um, twin slot antenna, SQUID readout
Abstract (up) For the first time, we have measured the optical noise equivalent power (NEP) in titanium (Ti) superconducting hot-electron nanobolometers (nano-HEBs). The bolometers were 2{\mu}mx1{\mu}mx20nm and 1{\mu}mx1{\mu}mx20nm planar antenna-coupled devices. The measurements were done at {\lambda} = 460 {\mu}m using a cryogenic black body radiation source delivering optical power from a fraction of a femtowatt to a few 100s of femtowatts. A record low NEP = 3x10^{-19} W/Hz^{1/2} at 50 mK has been achieved. This sensitivity meets the requirements for SAFARI instrument on the SPICA telescope. The ways for further improvement of the nano-HEB detector sensitivity are discussed.
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Publisher Place of Publication Editor
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Series Editor Series Title Abbreviated Series Title
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Area Expedition Conference
Notes To appear in Proc. 21st Int. Symp. on Spc. THz Technol., Oxford, UK, 23-25 March, 2010 Approved no
Call Number Serial 623
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Author Hubers, H.-W.; Semenov, A.; Richter, H.; Schwarz, M.; Gunther, B.; Smirnov, K.; Gol’tsman, G.; Voronov, B.
Title Heterodyne receiver for 3-5 THz with hot-electron bolometer mixer Type Conference Article
Year 2004 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 5498 Issue Pages 579-586
Keywords NbN HEB mixers
Abstract (up) Heterodyne receivers for applications in astronomy and planetary research need quantum limited sensitivity. In instruments which are currently build for SOFIA and Herschel superconducting hot electron bolometers (HEB) will be used to achieve this goal at frequencies above 1.4 THz. The local oscillator and the mixer are the most critical components for a heterodyne receiver operating at 3-5 THz. The design and performance of an optically pumped THz gas laser optimized for this frequency band will be presented. In order to optimize the performance for this frequency hot electron bolometer mixers with different in-plane dimensions and logarithmic-spiral feed antennas have been investigated. Their noise temperatures and beam patterns were measured. Above 3 THz the best performance was achieved with a superconducting bridge of 2.0 x 0.2 μm2 incorporated in a logarithmic spiral antenna. The DSB noise temperatures were 2700 K, 4700 K and 6400 K at 3.1 THz, 4.3 THz and 5.2 THz, respectively. The results demonstrate that the NbN HEB is very well suited as a mixer for THz heterodyne receivers up to at least 5 THz.
Address
Corporate Author Thesis
Publisher SPIE Place of Publication Editor Zmuidzinas, J.; Holland, W.S.; Withington, S.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference Millimeter and Submillimeter Detectors for Astronomy II
Notes Approved no
Call Number Serial 1483
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Author Richter, H.; Semenov, A.; Hubers, H.-W.; Smirnov, K.; Gol’tsman, G.; Voronov, B.
Title Phonon cooled hot-electron bolometric mixer for 1-5 THz Type Conference Article
Year 2004 Publication Proc. 29th IRMMW / 12th THz Abbreviated Journal Proc. 29th IRMMW / 12th THz
Volume Issue Pages 241-242
Keywords NbN HEB mixers
Abstract (up) Heterodyne receivers for applications in astronomy and planetary research need quantum limited sensitivity. In instruments which are currently built for SOFIA and Herschel, superconducting hot electron bolometers (HEB) are used to achieve this goal at frequencies above 1.4 THz. In order to optimize the performance for this frequency of hot electron bolometer mixers with different in-plane dimensions and logarithmic-spiral feed antennas have been investigated. Their noise temperatures and beam patterns were measured. Above 3 THz the best performance was achieved with a superconducting bridge of 2.0/spl times/0.2 /spl mu/m/sup 2/ incorporated in a logarithmic spiral antenna. The DSB noise temperatures were 2700 K, 4700 and 6400 K at 3.1 THz, 4.3 THz and 5.2 THz, respectively. The results demonstrate that the NbN HEB is very well suited as a mixer for THz heterodyne receivers up to at least 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 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1506
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Author Huebers, H.-W.; Semenov, A.; Richter, H.; Birk, M.; Krocka, M.; Mair, U.; Smirnov, K.; Gol’tsman, G. N.; Voronov, B. M.
Title Superconducting hot electron bolometer as mixer for far-infrared heterodyne receivers Type Conference Article
Year 2003 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 4855 Issue Pages 395-401
Keywords NbN HEB mixers
Abstract (up) Heterodyne receivers for applications in astronomy need quantum limited sensitivity. In instruments which are currently under development for SOFIA or Herschel superconducting hot electron bolometers (HEB) will be used to achieve this goal at frequencies above 1.4 THz. We present results of the development of a phonon-cooled NbN HEB mixer for GREAT, the German Receiver for Astronomy at Terahertz Frequencies, which will be flown aboard SOFIA. The mixer is a small superconducting bridge incorporated in a planar feed antenna and a hyperhemispherical lens. Mixers with logarithmic-spiral and double-slot feed antennas have been investigated with respect to their noise temperature, conversion loss, linearity and beam pattern. At 2.5 THz a double sideband noise temperature of 2200 K was achieved. The conversion loss was 17 dB. The response of the mixer was linear up to 400 K load temperature. The performance was verified by measuring an emission line of methanol at 2.5 THz. The measured linewidth is in good agreement with the linewidth deduced from pressure broadening measurements at millimeter wavelength. The results demonstrate that the NbN HEB is very well suited as a mixer for far-infrared heterodyne receivers.
Address
Corporate Author Thesis
Publisher SPIE Place of Publication Tucson, USA Editor Phillips, T. G.; Zmuidzinas, J.
Language Summary Language Original Title
Series Editor Series Title Presented at the Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Abbreviated Series Title
Series Volume 4855 Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference Millimeter and Submillimeter Detectors for Astronomy
Notes Approved no
Call Number Serial 335
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Author Huebers, H.-W.; Semenov, A.; Schubert, J.; Gol’tsman, G. N.; Voronov, B. M.; Gershenzon, E. M.; Krabbe, A.; Roeser, H.-P.
Title NbN hot-electron bolometer as THz mixer for SOFIA Type Conference Article
Year 2000 Publication Proc. SPIE Abbreviated Journal Proc. SPIE
Volume 4014 Issue Pages 195-202
Keywords NbN HEB mixers, airborne, stratospheric observatory, SOFIA
Abstract (up) Heterodyne receivers for applications in astronomy need quantum limited sensitivity. We have investigated phonon- cooled NbN hot electron bolometric mixers in the frequency range from 0.7 THz to 5.2 THz. The devices were 3.5 nm thin films with an in-plane dimension of 1.7 X 0.2 micrometers 2 integrated in a complementary logarithmic spiral antenna. The best measured DSB receiver noise temperatures are 1300 K (0.7 THz), 2000 K (1.4 THz), 2100 K (1.6 THz), 2600 K (2.5 THz), 4000 K (3.1 THz), 5600 K (4.3 THz), and 8800 K (5.2 THz). The sensitivity fluctuation, the long term stability, and the antenna pattern were measured. The results demonstrate that this mixer is very well suited for GREAT, the German heterodyne receiver for SOFIA.
Address
Corporate Author Thesis
Publisher SPIE Place of Publication Editor Melugin, R.K.; Roeser, H.-P.
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference Airborne Telescope Systems
Notes Approved no
Call Number Serial 1554
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Author Hübers, Heinz-Wilhelm; Semenov, A.; Richter, H.; Smirnov, K.; Gol'tsman, G.; Voronov, B.
Title Phonon cooled far-infrared hot electron bolometer mixer Type Abstract
Year 2002 Publication NASA/ADS Abbreviated Journal NASA/ADS
Volume Issue Pages
Keywords NbN HEB mixers
Abstract (up) Heterodyne receivers for applications in astronomy need quantum-limited sensitivity. At frequencies above 1.4 THz superconducting hot electron bolometers (HEB) can be used to achieve this goal. We present results of the development of a quasi-optical phonon-cooled NbN HEB mixer for GREAT, the German heterodyne receiver for SOFIA. Different mixers with logarithmic spiral and double slot feed antennas have been investigated with respect to their noise temperature, conversion loss, linearity and beam pattern at several frequencies between 0.7 THz and 5.2 THz. At 2.5 THz a double sideband noise temperature of 2200 K was achieved. The conversion loss was 16 dB. The response of the mixer was linear up to 400 K load temperature. This performance was verified by measuring an emission line of methanol at 2.5 THz. The results demonstrate that the NbN HEB is very well suited as a mixer for FIR heterodyne receivers.
Address Monterey, CA
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 Far-IR, Sub-mm & MM Detector Technology Workshop, 1-3 April 2002
Notes id.37 Approved no
Call Number Serial 1534
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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.
Title Optical mixing in thin YBa2Cu3O7-x films Type 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 (up) 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.
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 1619
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Author Hartogh, P.; Crovisier, J.; de Val-Borro, M.; Bockelée-Morvan, D.; Biver, N.; Lis, D. C.; Moreno, R.; Jarchow, C.; Rengel, M.; Emprechtinger, M.; Szutowicz, S.; Banaszkiewicz, M.; Bensch, F.; Blecka, M. I.; Cavalié, T.; Encrenaz, T.; Jehin, E.; Küppers, M.; Lara, L.-M.; Lellouch, E.; Swinyard, B. M.; Vandenbussche, B.; Bergin, E. A.; Blake, G. A.; Blommaert, J. A. D. L.; Cernicharo, J.; Decin, L.; Encrenaz, P.; de Graauw, T.; Hutsemekers, D.; Kidger, M.; Manfroid, J.; Medvedev, A. S.; Naylor, D. A.; Schieder, R.; Thomas, N.; Waelkens, C.; Roelfsema, P. R.; Dieleman, P.; Güsten, R.; Klein, T.; Kasemann, C.; Caris, M.; Olberg, M.; Benz, A. O.
Title HIFI observations of water in the atmosphere of comet C/2008 Q3 (Garradd) Type Journal Article
Year 2010 Publication Astron. Astrophys. Abbreviated Journal
Volume 518 Issue Pages L150 (1 to 5)
Keywords HEB mixer applications, HIFI, Herschel, comets: individual: C/2008 Q3 / radio lines: general / submillimeter: general / techniques: spectroscopic
Abstract (up) High-resolution far-infrared and sub-millimetre spectroscopy of water lines is an important tool to understand the physical and chemical properties of cometary atmospheres. We present observations of several rotational ortho- and para-water transitions in comet C/2008 Q3 (Garradd) performed with HIFI on Herschel. These observations have provided the first detection of the 212–101 (1669 GHz) ortho and 111–000 (1113 GHz) para transitions of water in a cometary spectrum. In addition, the ground-state transition 110–101 at 557 GHz is detected and mapped. By detecting several water lines quasi-simultaneously and mapping their emission we can constrain the excitation parameters in the coma. Synthetic line profiles are computed using excitation models which include excitation by collisions, solar infrared radiation, and radiation trapping. We obtain the gas kinetic temperature, constrain the electron density profile, and estimate the coma expansion velocity by analyzing the map and line shapes. We derive water production rates of 1.7–2.8 × 1028 s-1 over the range rh = 1.83–1.85 AU.
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 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 1088
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