My UROP Experience:
Diagnostics and Hardware Upgrades at the Low Background Counting Facility
John Greavu
Sponsor: Professor Priscilla Cushman
June 4, 2014
My project this past spring involved the Soudan Underground Laboratory’s Low Background Counting Facility. The Low Background Counting Facility, or LBCF, is housed next to the Super Cryogenic Dark Matter Search (SuperCDMS) half-a-mile underground in an old northern Minnesota iron mine which has now been converted into a fully-equipped modern physics lab. The LBCF is a 40 x 35 x 100 ft. hall with an active muon veto shield—left over from the Soudan 2 proton decay experiment— lining nearly all of the facility, save for the floor. Also inside the LBCF is a neutron multiplicity meter, capable of fast neutron searches. This and the muon veto shield provide for interesting studies of environments with an ultra low flux of particles, studies crucial for understanding and developing the field underground physics. Such studies have applications in many exciting areas of contemporary physics, such as SuperCDMS and other dark matter searches (for one, neutrons can be virtually indistinguishable from WIMPs in the data), as well as searches for neutrino-less double beta decay, or any rare event searches, really.
The goals this semester were to understand the veto shield and its tendencies as well as implement upgrades to the Soudan shield while using the partial local shield setup as a test bed for possible hardware changes. Myself, alongside another UROP undergraduate research assistant, Joe Jeffers, worked with Professor Cushman and post-doctoral students Anthony Villano and Matthew Fritts in this endeavor.
In January, we moved the local shield setup from the old Tate Laboratory of Physics to Lab 450 in the new Physics and Nanotechnology building. The shield is made up of daisy-chained hexagonal aluminum gas proportional tubes, each with a gold wire strung down the middle to relay information about ionizing