39th Int. Conf. on Infrared, Millimeter, and THz Waves
September 14-19, 2014
The University of Arizona, Tucson, AZ
M4/B - 4. Astronomy and Planetary Science II - 5. Atmospheric and Earth Sciences
Monday, September 15, 2014 4:00 pm to 5:30 pm
Room: Catalina Room
Chairperson: Christopher Groppi
4:00 pm 4:00 pm : Heterodyne Receivers For High Frequency THz Astrophysics
Presenter: Heinz-Wilhelm Huebers

The performance of heterodyne receivers for frequencies beyond 1.4 THz will be reviewed. Emphasis will be on the development of the 4.7-THz frequency channel for the GREAT heterodyne spectrometer on SOFIA. This receiver is based on a phonon-cooled hot-electron bolometric mixer and a quantum-cascade laser as local oscillator.

Author(s):
Heinz-Wilhelm Huebers - German Aerospace Center (DLR)
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4:30 pm 4:30 pm : SAFARI: A Far-Infrared Imaging Spectrometer For SPICA
Presenter: Willem Jellema

The next great leap forward in far-infrared astronomy will be the JAXA-led mission SPICA [1] which is anticipated to be launched around 2025. Filling the gap between Herschel, ALMA and JWST this observatory will feature a cryogenic 3m class telescope opening up the scientific window of zodiacal background limited observations in the far-infrared. Making full advantage of a deeply cooled telescope (<6K) the Safari instrument [2] on SPICA is a highly sensitive wide-field imaging photometer and spectrometer operating in the 34-210 µm wavelength range. Utilizing Nyquist-sampled filled arrays of very sensitive Transition Edge Sensors (TES) [3], Safari offers a photometric imaging (R ò 2), and a low (R = 100) and medium resolution (R = 2000 at 100 µm) imaging spectroscopy mode in three photometric bands within a 2'x2' instantaneous field of view. In this paper we briefly present the key scientific themes that SPICA-Safari will address. We furthermore present the system concepts currently being studied for the Safari instrument. We will discuss the overall instrument layout [4] (see Fig. 2) designed around a compact Mach-Zehnder interferometer [5] and large-format TES arrays and provide a general overview of the system architecture, its components and functions. The conceptual design status of the Focal Plane Instrument is described in a bit more detail with special emphasis on the main challenges and critical technologies of Safari. The paper is concluded by a summary and discussion of the expected instrument performance and astronomical sensitivities.

Author(s):
Willem Jellema - SRON Netherlands Institute for Space Research
Peter Roelfsema - SRON Netherlands Institute for Space Research
Bruce Sibthorpe - SRON Netherlands Institute for Space Research
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4:45 pm 4:45 pm : Engineering And Science Data From SuperCam: A 64-Pixel Heterodyne Receiver For CO J=3-2 At 345 GHz
Presenter: Jenna Kloosterman

SuperCam is a 64-pixel heterodyne imaging array designed for use on ground-based submillimeter telescopes to observe the astrophysically important CO J=3-2 emission line at 345 GHz. Each pixel in the array has its own integrated superconductor-insulator-superconductor (SIS) mixer and low noise amplifier. In spring 2012, SuperCam was installed on the University of Arizona Submillimeter Telescope (SMT) for its first engineering run. SuperCam completed two additional science runs in May 2013 and March 2014. During these science runs, over 80% of the pixels were in operation with a median double sideband receiver temperature of 104 K and an Allan time of ~100 s.

Author(s):
Jenna Kloosterman - University of Arizona
Brandon Swift - University of Arizona
William Peters - University of Arizona
David Lesser - University of Arizona
Craig Kulesa - University of Arizona
Casey Honniball - University of Arizona
Christian Villegas - University of Arizona
Paul Schickling - University of Arizona
Christopher Walker - University of Arizona
Christopher Groppi - Arizona State University
Hamdi Mani - Arizona State University
Kristina Davis - Arizona State University
Caleb Wheeler - Arizona State University
Todd Veach - NASA Goddard
Sander Weinreb - Caltech
Jacob Kooi - Caltech
Arthur Lichtenberger - University of Virginia
Patrick Puetz - University of Cologne
Gopal Narayanan - University of Massachusetts
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5:00 pm 5:00 pm : Spatial/Spectral Interferometry Development For Far-Infrared Space Applications
Presenter: Locke Spencer

The laboratory development of spatial/spectral interferometry for use in Far-IR space-based applications is discussed in the context of recent Far-Infrared Space Interferometer Critical Assessment (FISICA) efforts. Far-infrared spatial/spectral interferometry techniques will provide the combined spatial and spectral resolution required by the next generation of astronomical Far-IR instruments.

Author(s):
Locke Spencer - University of Lethbridge
David Naylor - University of Lethbridge
Giorgio Savini - University College London
Peter Ade - Cardiff University
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5:15 pm 5:15 pm : Determination Of Water Vapor Continuum Absorption, Using Long-Path THz-TDS Without The Cross-Term
Presenter: Yihong Yang

We report the latest experimental determination of the water vapor continuum absorption within the atmospheric THz windows, using the long-path THz-TDS system. The continuum absorption was determined, based on the total water vapor absorption for a density of 11.2 g/m3 and the calculated Molecular Response Theory (MRT) resonant line absorption. The experimentally determined RH 0% reference signal eliminated the undesirable cross-term and thereby, increased the accuracy of the measurements.

Author(s):
Daniel Grischkowsky - Oklahoma State University
Yihong Yang - Oklahoma State University
Mahboubeh Mandehgar - Oklahoma State University
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