Stray light suppression in the Goddard IRAM 2-Millimeter Observer (GISMO)

The Goddard-IRAM Superconducting 2 Millimeter Observer (GISMO) is an 8x16 Transition Edge Sensor (TES) array of bolometers built as a pathfinder for TES detector development efforts at NASA Goddard Space Flight Center. GISMO has been used annually at the Institut de Radioastronomie Millimétrique (IRAM) 30 meter telescope since 2007 under engineering time and was opened in the spring of 2012 to the general astronomical community. The spring deployment provided an opportunity to modify elements of the room temperature optics before moving the instrument to its new permanent position in the telescope receiver cabin. This allowed for the possibility to extend the cryostat, introduce improved cold baffling and thus further optimize the stray light performance for final astronomical use of the instrument, which has been completed and validated. We will demonstrate and discuss several of the methods used to quantify and limit the influence of stray light in the GISMO camera.

[1]  Edward J. Wollack,et al.  Electromagnetic and Thermal Properties of a Conductively Loaded Epoxy , 2008 .

[2]  L. Kauder,et al.  Spacecraft Thermal Control Coatings References , 2005 .

[3]  M. J. Persky.  Review of black surfaces for space-borne infrared systems , 1999 .

[4]  Nathan Marcuvitz.  Waveguide Handbook , 1951 .

[5]  Edward J. Wollack,et al.  Mirror illumination and spillover measurements of the Atacama Cosmology Telescope , 2012, Other Conferences.

[6]  Dominic J. Benford,et al.  Backshort-Under-Grid arrays for infrared astronomy , 2006 .

[7]  Edward J. Wollack,et al.  Millimeter-wave antireflection coating for cryogenic silicon lenses. , 2006, Applied optics.

[8]  Peter A. R. Ade,et al.  Thermal filtering for large aperture cryogenic detector arrays , 2006, SPIE Astronomical Telescopes + Instrumentation.

[9]  Ieee Microwave Theory,et al.  Quasioptical systems : Gaussian beam quasioptical propagation and applications , 1998 .

[10]  Paul Mirel,et al.  Radiometric-Waveguide Calibrators , 2007, IEEE Transactions on Instrumentation and Measurement.

[11]  Dominic J. Benford,et al.  A 2 mm Bolometer Camera for the IRAM 30 m Telescope , 2007 .

[12]  Dominic J. Benford,et al.  Design and performance of a high-throughput cryogenic detector system , 2008, Astronomical Telescopes + Instrumentation.

[13]  Giampaolo Pisano,et al.  A review of metal mesh filters , 2006, SPIE Astronomical Telescopes + Instrumentation.

[14]  H. Macleod,et al.  Thin-Film Optical Filters , 1969 .

[15]  Hiroshige Yoshida,et al.  SHARC II: a Caltech submillimeter observatory facility camera with 384 pixels , 2003, SPIE Astronomical Telescopes + Instrumentation.