LN bulk tank ready at the Yates Shaft

Facilities Technician Kevin Ehnes, in the basket, operates a lift to reach the straps used to hoist the new liquid nitrogen bulk tank into place. Pipes will deliver the nitrogen to a station inside the headframe. Nitrogen will be loaded into Dewar tanks for transport underground.
Credit: 
Matt Kapust

A ready supply of icy cold liquid nitrogen is essential to operate both the experiments at the Davis Campus, so last week a new 3,000-gallon bulk tank was installed near the top of the Yates Shaft, just outside the headframe.

Science Liaison Director Jaret Heise points out that the Large Underground Xenon (LUX) dark matter detector will require delivery of liquid nitrogen “almost daily.” The Majorana Demonstrator experiment depends on liquid nitrogen to keep its germanium crystals cold. Majorana also uses nitrogen as the “cover gas” inside its super-clean glove boxes.

Experiment Safety Manager Chuck Lichtenwalner says a system is being designed to pipe liquid nitrogen from the bulk tank outside into the headframe building itself, where it can be transferred to containers called Dewar flasks for transport to the Davis Campus 4,850 feet underground. That system will come in handy with the snow flies.

Technical Support Lead Jim Hanhardt helped develop safe transport procedures for nitrogen. Lichtenwalner is deputy chairman of the Cryogen Safety Committee, which includes members from Fermilab and Berkeley Lab. The committee reviewed calculations and analyses for “oxygen deficiency hazards” to insure safe use of nitrogen underground.