Conveners
C2Or2A: Non-Aerospace Coolers III: 4K and Sub Kelvin
- Franklin Keith Miller (University of Wisconsin-Madison)
- Amir Jahromi (NASA)
Cryomech has developed a small capacity, low vibration helium reliquefier for use with commercial NMR cryostats. NMR systems are highly sensitive to vibration and thus utilize liquid helium to cool the magnet. Due to the helium shortage and rising cost of helium, many small labs cannot operate their NMR systems. Large facilities with multiple NMR systems can utilize a large-scale liquid helium...
Quantum detection of single photon achieves its highest sensitivity for temperatures below 2 K. The cooling requirements for such applications are very low, a few milliwatts for current harness heat intercept and radiation shielding. For that purpose, we are developing a compact cryocooler based on a 4He JT cooler. A Stirling-type pulse tube will provide the pre-cooling of two intermediate...
CMB-S4 is a ground-based experiment that will use large-format bolometer arrays to map Cosmic Microwave Background (CMB) polarization with unprecedented sensitivity, including the search for a B-mode polarization pattern associated with cosmic inflation. The focal planes on which the superconducting detectors are mounted each weigh about 20 kg and must be cooled at 100 mK. To reach this...
ABSTRACT:Small-scale helium liquefiers with typical liquid-helium production of the order of tens of liters per day are required for cryogenic applications, such as cryogenic research experiments and operation of superconducting magnets in hospitals. These liquefiers are typically based on 4 K regenerative cryocoolers, including Gifford-McMahon (GM) or pulse-tube (PT) cryocooler. However, due...
Adsorption refrigeration is a significant method for achieving temperatures below 1 K. The process involves pumping a helium tank to a high vacuum by adsorbents, resulting in the liquid helium reaching sub-Kelvin temperatures. The adsorbents are then heated to desorb 4He, which condenses in the region below the critical temperature, and the adsorption refrigeration cycle is repeated. This...
