LUX detector cooling with xenon

The Large Underground Xenon dark-matter experiment entered an important testing stage at the surface lab last week?the detector?s first-ever cool-down with xenon.

The LUX team conducted a cool-down last spring using argon gas. Argon has a lower condensation temperature than xenon, which allowed the researchers to test systems without the added risks associated with liquefied gases.

That run was successful, so about a week ago the team began ?Run 2,? this time adding xenon to the detector. The detector will hold 350 kilograms of liquid xenon in a double-walled titanium cryostat. The xenon is slowly being cooled by liquid nitrogen to a target temperature of about minus 100 C (minus 148 F).  LUX researcher Monica Pangilinan, a post-doctoral fellow from Brown University, said the hottest part of the detector this afternoon was minus 81 C (minus 114 F).

Run 2 will continue until January. Then the detector will be warmed up and prepared for a trip next spring to the Davis Campus, 4,850 feet underground, where it will begin its search for dark-matter particles called WIMPs.