Magnetic Shielding for the NNbar Experiment at DUSEL

The NNbar Experiment hopes to study neutron/antineutron oscillations at DUSEL. Cold Neutrons will be dropped from a reactor and fall approximately 1.5 km within a vacuum tube before anitneutrons are detected at the bottom. The possible long flight time of the neutrons is what makes DUSEL an excellent facility to house the experiment. This experiment will increase the sensitivity of detecting the neutron oscillations by a factor greater than 1000 compared to previous experiments, and will test a number of theories important to theoretical and particle physicists.

Learn more about the proposed experiment by clicking the attachment below:

In order for the neutrons to oscillate into antineutrons, a number of physical conditions need to be met. One of these conditions is that during the neutron’s descent, it cannot encounter magnetic fields. Therefore, a magnetic compensating apparatus needs to be constructed that would minimize magnetic fields inside the flight tube to less than 10 nT.

The 3 components of the magnetic field are offset independently. The component of the field that runs parallel to the flight path of the neutron (vertical) is counterbalanced by wrapping a series of loops around the vacuum tube, essentially creating a huge solenoid. (figure 1). The two horizontal components are compromised using a series of 4 current conducting cables for each component. (figure 2)

Preliminary local magnetic field measurements were taken in both the Ross and Yates shafts at Sanford Lab to investigate the feasibility of creating this experimental device at DUSEL. The attachment below shows the data taken.

Report of Findings

George and Mark setting up the Magnetometer in the Ross Cage

BHSU Quarknet Home