A technician adds finishing touches to a tunnel leading to the Majorana Demonstrator experiment 4,850 feet underground in the Sanford Underground Research Facility. Image: Matt Kapust/Sanford Underground Research Facility
This article appeared in Deep Thoughts [PDF], a Sanford Laboratory publication, on March 26.
Majorana Demonstrator spokesperson Steve Elliott has been waiting for today for 12 years. “It’s certainly a big milestone for our collaboration,” Elliott said this morning, before going underground. The Majorana Demonstrator collaboration began moving their experiment into the Davis Campus on the 4850 Level this afternoon.
Elliott and other founding members of the Majorana collaboration began planning their experiment back in 2000, the same year scientists first publicly proposed converting Homestake into an underground laboratory. Majorana’s ultimate goal is to detect a rare form of radioactive decay called “neutrinoless double-beta decay,” a discovery would help determine whether neutrinos are their own anti-particles. That discovery, in turn, could help scientists understand how matter evolved. In other words, Majorana could help explain why we exist.
The experiment, now being installed in the Transition Cavern of Davis Campus, is called a “demonstrator” because its purpose is to demonstrate that this technology—using ultra-pure crystals of a germanium isotope in a detector deep underground—can achieve background radiation levels low enough to justify building a larger detector. The GERmanium Detector Array (GERDA), a similar experiment at Gran Sasso National Laboratory in Italy, already is testing the same technology.
Majorana will run through 2017. Results from Majorana and GERDA will be evaluated to determine how to build a larger detector.
Elliott, who is a physicist at Los Alamos National Laboratory, said one of the first steps this week will be the installation of a “soft-wall clean room” that will consist of wide plastic strips hanging from the ceiling of the Majorana assembly room. That’s where the detector itself will operate. Extra HEPA filters inside the soft walls will keep the laboratory’s already clean air even cleaner.
