Ultra-low Temperature Polarization-sensitive Receiver For Atacama Cosmology Telescope
Cool science below 100 mK at 5140 meters elevation! Dilution refrigerator for Atacama Cosmology Telescope
The Receiver temperature-
The dilution refrigerator (DR), installed inside of the receiver, is remotely operated via Ethernet link and can move with acceleration of 1 G both vertically in the scan range of +/- 35 degree from neutral position, as well as horizontally. The air cooling system for electronics and pumps allows continuous operation at low atmospheric pressure of 500 mbar.
The receiver schematic is designed as a vacuum chamber with 50 K and 4 K shields on G-10 isolating supports, cooled by a dedicated Cryomech pulse-tube (PT) cryo-cooler PT-415 seen in the left lower corner.
The PT as well as dilution core are installed tilted to the optical central axis to allow DR operation in full scan range.
The test results both as is and integrated with the receiver have shown that it is fully compliant with technical specification set up by the ACTPol collaboration. Employing the highly-customized remotely controlled liquid-cryogen-
In Spring 2013, the first 150 GHz kilo-TES polarimeters array package (PA1) was deployed for operation in the ACTPol receiver on the ACT site. In early 2014, a second 150 GHz array package (PA2), and a multichroic 90/150 GHz array package (PA3) will be deployed for a complete focal plane across three optics tubes.
As of June 2013, the ACTPol receiver has been successfully shipped to and integrated on the ACT site in Chile. First light and commencement of season one operations (PA1) was in July 2013.
Operations with full focal-plane deployment are projected for Spring 2014.
Janis Research Company, LLC