High Energy Physics Lab

Why is there a high energy physics lab at Soudan Underground Mine State Park?
By constructing the lab at the bottom of the mine, scientists use the nearly half-mile depth as a shield to filter out cosmic rays. Without these rays, scientists can conduct sensitive experiments they are unable to do aboveground. The lab is run by the University of Minnesota. This link leads to an external site.

How did they build the lab?
The lab was built using modern underground mining methods. All materials used in construction, or removed from the lab, were lowered or raised in the shaft using the same system the mine did when active.

What experiments are conducted in the lab?
There are two major experiments in the lab now: CDMS and MINOS. A third experiment, Proton Decay, has been put on hold.

Soudan 2 Proton Decay experiment logo.

What is CDMS?
CDMS stands for Cryogenic Dark Matter Search. This experiment's purpose is to directly detect dark matter particles other than neutrinos.

MINOS experiment logo

What is MINOS?
MINOS stands for Main Injector Neutrino Oscillation Search. The experiment's purpose is to measure the mass of particles called neutrinos, which are smaller than the nuclei of atoms.

What is Soudan 2 (Proton Decay)?
The Soudan 2 Proton Decay experiment operated from 1989-2001. The goal of the experiment was to observe the decay of a proton. While this was not observed, much valuable data was collected, leading to the MINOS experiment.

MINOS crew in front of a detector plate.

MINOS crew in front of first installed detector plate.


Completed cavern before installation of MINOS experiment.

Completed cavern before installation of MINOS experiment.

Installed MINOS experiment equipment.

Installed MINOS experiment equipment.