Superfluid-tight cryogenic receiver with continuous sub-Kelvin cooling for EXCLAIM

Abstract

The EXperiment for Cryogenic Large-Aperture Intensity Mapping (EXCLAIM) is a balloon-borne telescope designed to survey star formation over cosmological time scales using intensity mapping in the 420 - 540 GHz frequency range. EXCLAIM uses a fully cryogenic telescope coupled to six on-chip spectrometers featuring kinetic inductance detectors (KIDs) to achieve high sensitivity, allowing for fast integration in dark atmospheric windows. The telescope receiver is cooled to $\approx$ 1.7 K by immersion in a superfluid helium bath and enclosed in a superfluid-tight shell with a meta-material anti-reflection coated silicon window. In addition to the optics and the spectrometer package, the receiver contains the magnetic shielding, the cryogenic segment of the spectrometer readout, and the sub-Kelvin cooling system. A three-stage continuous adiabatic demagnetization refrigerator (CADR) keeps the detectors at 100 mK while a ${}^4$He sorption cooler provides a 900 mK thermal intercept for mechanical suspensions and coaxial cables. We present the design of the EXCLAIM receiver and report on the flight-like testing of major receiver components, including the superfluid-tight receiver window and the sub-Kelvin coolers.

13 pages, 7 figures, 1 table

References in corpus (10)

• The Completed SDSS-IV extended Baryon Oscillation Spectroscopic Survey: Cosmological Implications from two Decades of Spectroscopic Surveys at the Apache Point observatory
• Line-Intensity Mapping: Theory Review
• Large-aperture wide-bandwidth antireflection-coated silicon lenses for millimeter wavelengths
• A User's Guide to Extracting Cosmological Information from Line-Intensity Maps
• A Compact Cryogenic Thermal Source for Detector Array Characterization
• Extragalactic Science with the Experiment for Cryogenic Large-aperture Intensity Mapping
• Sub-Kelvin cooling for two kilopixel bolometer arrays in the PIPER receiver
• Anti-reflection Coated Vacuum Window for the Primordial Inflation Polarization ExploreR (PIPER) balloon-borne instrument
• Superfluid Liquid Helium Control for the Primordial Inflation Polarization Explorer Balloon Payload
• Optimization of an Optical Testbed for Characterization of EXCLAIM u-Spec Integrated Spectrometers

Cited by in corpus (1)

• Silicon-based vacuum window for millimeter and submillimeter-wave astrophysics