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Bibliographic Details
Main Authors: King, Cesiley L., Gullet, Ian, Anderson, Adam J., Benson, Bradford A., Bihary, Rick, Fan, Haichen, Nagy, Johanna M., Nguyen, Hogan, Ruhl, John E., Simon, Sara M.
Format: Preprint
Published: 2024
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Online Access:https://arxiv.org/abs/2406.17695
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author King, Cesiley L.
Gullet, Ian
Anderson, Adam J.
Benson, Bradford A.
Bihary, Rick
Fan, Haichen
Nagy, Johanna M.
Nguyen, Hogan
Ruhl, John E.
Simon, Sara M.
author_facet King, Cesiley L.
Gullet, Ian
Anderson, Adam J.
Benson, Bradford A.
Bihary, Rick
Fan, Haichen
Nagy, Johanna M.
Nguyen, Hogan
Ruhl, John E.
Simon, Sara M.
contents We present the design and validation of a variable temperature cryogenic blackbody source, hereinafter called a cold load, that will be used to characterize detectors to be deployed by CMB-S4, the next-generation ground-based cosmic microwave background (CMB) experiment. Although cold loads have been used for detector characterization by previous CMB experiments, this cold load has three novel design features: (1) the ability to operate from the 1 K stage of a dilution refrigerator (DR), (2) a 3He gas-gap heat switch to reduce cooling time, and (3) the ability to couple small external optical signals to measure detector optical time constants under low optical loading. The efficacy of this design was validated using a 150 GHz detector array previously deployed by the Spider experiment. Thermal tests showed that the cold load can be heated to temperatures required for characterizing CMB-S4's detectors without significantly impacting the temperatures of other cryogenic stages when mounted to the DR's 1 K stage. Additionally, optical tests demonstrated that external signals can be coupled to a detector array through the cold load without imparting a significant optical load on the detectors, which will enable measurements of the CMB-S4 detectors' optical time constants.
format Preprint
id arxiv_https___arxiv_org_abs_2406_17695
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Design and Validation of a Cold Load for Characterization of CMB-S4 Detectors
King, Cesiley L.
Gullet, Ian
Anderson, Adam J.
Benson, Bradford A.
Bihary, Rick
Fan, Haichen
Nagy, Johanna M.
Nguyen, Hogan
Ruhl, John E.
Simon, Sara M.
Instrumentation and Methods for Astrophysics
We present the design and validation of a variable temperature cryogenic blackbody source, hereinafter called a cold load, that will be used to characterize detectors to be deployed by CMB-S4, the next-generation ground-based cosmic microwave background (CMB) experiment. Although cold loads have been used for detector characterization by previous CMB experiments, this cold load has three novel design features: (1) the ability to operate from the 1 K stage of a dilution refrigerator (DR), (2) a 3He gas-gap heat switch to reduce cooling time, and (3) the ability to couple small external optical signals to measure detector optical time constants under low optical loading. The efficacy of this design was validated using a 150 GHz detector array previously deployed by the Spider experiment. Thermal tests showed that the cold load can be heated to temperatures required for characterizing CMB-S4's detectors without significantly impacting the temperatures of other cryogenic stages when mounted to the DR's 1 K stage. Additionally, optical tests demonstrated that external signals can be coupled to a detector array through the cold load without imparting a significant optical load on the detectors, which will enable measurements of the CMB-S4 detectors' optical time constants.
title Design and Validation of a Cold Load for Characterization of CMB-S4 Detectors
topic Instrumentation and Methods for Astrophysics
url https://arxiv.org/abs/2406.17695