论文信息 - A Continuous 100-mK Helium-Light Cooling System for MUSCAT on the LMT

A Continuous 100-mK Helium-Light Cooling System for MUSCAT on the LMT

The MUSCAT instrument is a large-format camera planned for installation on the Large Millimeter Telescope in 2018. MUSCAT requires continuous cooling of several large-volume stages to sub-Kelvin temperatures, with the focal plane cooled to 100 mK. Through the use of continuous sorption coolers and a miniature dilution refrigerator, the MUSCAT project can fulfil its cryogenic requirements at a fraction of the cost and space required for conventional dilution systems. Our design is a helium-light system, using a total of only 9 L of helium-3 across several continuous cooling systems, cooling from 4 K to 100 mK. Here we describe the operation of both the continuous sorption and the miniature dilution refrigerator systems used in this system, along with the overall thermal design and budgeting of MUSCAT. MUSCAT will represent the first deployment of these new technologies in a science-grade instrument and will prove the concept as a viable option for future large-scale experiments such as CMB-S4.

[1] A. Woodcraft,et al. Millikelvin thermal conductance measurements of compact rigid thermal isolation joints using sapphire–sapphire contacts, and of copper and beryllium–copper demountable thermal contacts , 2007 .

[2] E. Pascale,et al. Mexico-UK Sub-millimeter Camera for Astronomy , 2018 .

[3] R. Ouboter,et al. A Realization of a London-Clarke-Mendoza Type Refrigerator , 1965 .

[4] G M Klemencic,et al. A continuous dry 300 mK cooler for THz sensing applications. , 2016, The Review of scientific instruments.

[5] H. London,et al. OSMOTIC PRESSURE OF He$sup 3$ IN LIQUID He$sup 4$, WITH PROPOSALS FOR A REFRIGERATOR TO WORK BELOW 1 K , 1962 .