Cordless Power Supply for Encased Photo Multiplier Tubes
Open Access
- Author:
- Hug, Samantha
- Area of Honors:
- Physics
- Degree:
- Bachelor of Science
- Document Type:
- Thesis
- Thesis Supervisors:
- Douglas Cowen, Thesis Supervisor
Richard Wallace Robinett, Thesis Honors Advisor - Keywords:
- PMT
Photo-Multiplier Tubes
Water Cherenkov Detector
WATCHMAN
Solenoids
Cordless Power Supply - Abstract:
- Neutrinos are produced by a variety of sources, such as supernovae, solar fission, and nuclear reactors, and can be measured using Cherenkov radiation. WATCHMAN is a water Cherenkov detector that is being built to detect whether or not a nearby reactor is on. Cherenkov radiation can be measured by Photo-Multiplier Tubes (PMTs) to determine a neutrino’s energy, direction,and flavor. However, these PMTs may be encased in acrylic shells to make them more pressure resistant. Having a cordless power supply will make the shells more pressure resistant. The basis of the design for the cordless power supply is two solenoids, with one inside of the other; the inner with a set AC current running through it which induces a current in the outer coil due to the changing magnetic field, which was simulated in COMSOL Multiphysics. PMTs are extremely sensitive to magnetic fields, so the power supply needs to be shielded. Introducing an iron core increases the magnetic field, as well as the current, voltage, and power for the outer coil, and the voltage and power for the inner coil. Increasing the amount of turns for the inner coil, as well as increasing the radius of the inner coil’s wire, increases the current, voltage, and power for the outer coil, and the voltage and power for the inner coil. Conversely, increasing the amount of turns for the outer coil, as well as increasing the radius of the outer coil’s wire, decreases the current,voltage, and power for the outer coil, and the voltage and power for the inner coil. The Mu-Metal shielding works as expected for small thicknesses, but as the thickness increases, the shielding works less. The final design has an iron core, with the inner coil with a wire radius of 1 mm, and twenty turns, and an outer coil with a wire radius of 1.25 mm, and twenty turns. The mu-metal works best with a thickness of 0.5 mm. The inner coil has an AC current with a peak value of 1.65 Amps, and the outer coil has a resistor attached to it of 5 Ω.