Particle Physics Underground
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| Students and staff at the Soudan Underground Laboratory make final preparations for installing one of nearly 500 detector planes of the MINOS experiment. The University of Minnesota manages the laboratory and is responsible for many components of the MINOS detector. The cavern wall on the right-hand side of the picture is the "canvas" of artist Joseph Giannetti, whose now-finished mural depicts some of the history of neutrino physics and the ongoing work of the laboratory. |
| Photo by Jerry Meier |
The largest Minnesota elementary particle physics project is the Main Injector Neutrino Oscillation Search (MINOS). Professors Heller, Marshak, Peterson, Ruddick, and Urheim contribute to the experiment. MINOS is currently being installed a half mile below ground at the Soudan Underground Mine State Park near Tower, Minnesota. The objective of MINOS is to make precise measurements of neutrino flavor oscillations, the spontaneous transformation of one type of neutrino into another. This will be accomplished by comparing the composition of a neutrino beam produced with the Fermilab main injector at two locations: one near the production point and the other in the Soudan mine, 734 kilometers away. After oscillations are confirmed, there will be many details to sort out that could provide insight into CP violation (matter/antimatter asymmetry) and the mystery of flavors (why there are three generations of quarks and leptons).
Also located in the underground laboratory is CDMSII, the Cryogenic Dark Matter Search. Professor Cushman's group participated in the design of CDMSII to search for WIMPs or Weakly Interacting Massive Particles. These so-far-unobserved objects could explain the nature of "dark matter," the roughly nine tenths of the matter in the universe that we infer from the motion of stars and galaxies, but which cannot be accounted for by the luminous objects we can observe. As the name implies, the WIMPs deposit very little energy in passing through matter. Thus the detectors must be low-noise and low-temperature, and the low-background environment of the underground laboratory is crucial.
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