Cryogen-free dilution refrigerator for ACTPOL polarization- sensitive receiver

[摘要] We present a new cryogenic receiver for the Atacama Cosmology Telescope (ACT), a six-meter diameter off-axis Gregorian telescope located at an altitude of 5,200 meters (17,000 ft.) on Cerro Toco, in Northern Chile. The focal plane contains 3000 polarization-sensitive transition edge sensor (TES) bolometers, and is cooled to below 100 mK with a removable pulse-tube based customised JDry-100 dilution refrigerator insert. The optical tubes and the rest of the receiver are cooled with a dedicated pulse tube to below 3 K. Details of the receiver- to-telescope integration and first season on-site operation are described, including detector base temperature stability in vertical and tilted position as well as remote operation via Ethernet link.

[发布机构] Janis Research Company, LLC, 225 Wildwood Ave., Wobum; MA; 01801, United States^1;Department of Physics and Astronomy, University of Pennsylvania, 209 S 33rd St., Philadelphia; PA; 19104, United States^2;Department of Physics, West Chester University of Pennsylvania, 720 South Church St., West Chester; PA; 19383, United States^3

[关键词] Base temperature;Dilution refrigerator;Ethernet link;Northern Chile;Polarization sensitive;Remote operation;Site operations;Transition-edge sensors