Paper 13094-188
Cryoscope Pathfinder: testing a new approach to low background, diffraction limited, NIR imaging with exceptionally large field of view
On demand | Presented live 18 June 2024
Abstract
Cryoscope will be a diffraction limited 1.2m telescope with 50 deg2 field of view contributing less thermal background than the dark K band sky at the Concordia Base in Antarctica. Cryoscope Pathfinder is 26cm version which has been built and is soon to be deployed at Dome C to retire technical risks. This paper reviews key design choices that make the substantial increase in field of view and reduction in thermal background possible. We address the technical challenges associated with the new approach and with operation over the > 100 C temperature difference between laboratory and winter at Dome C. The athermal window support and bonding are described. The baffling and thermal models are presented along with strategies for preventing condensation on the large vacuum window which radiates significant heat into the cryogenically cooled telescope. We conclude with a vision for a modular prefabricated tower to raise the telescope above the 25-30 m inversion layer, and an approach to image stabilization, so that diffraction limited imaging can be achieved over the full field of view.
Presenter
Caltech (United States)
Roger has being building cryogenically cooled detector systems for 44 years. He led the development of 3 infrared cameras and 6 CCD cameras on the Palomar or Keck telescopes. He was lead engineer for the Zwicki Transient facility and instrument architect for a new high-throughput spectrograph for Palomar. He is conducting CMOS test program in support of space missions after working with JPL for many years to develop a high Strehl projection system for emulation of high precision astronomy experiments (e.g. Euclid, WFIRST), characterizing sub-pixel effects in NIR and optical sensors. He has been a frequent consultant to JPL for widefield imaging missions (Kepler and Euclid) and has served on NSF/DOE reviews of DECam, DESI, and LSST camera. He is PI on several grants to develop quantizing CCDs with readout times appropriate for astronomical observing.