Simulation and Detection of Cherenkov Light in Water Neutrino Detectors

• Author / Creator

  Minchenko, Dmytro

• Cherenkov light plays a crucial role in particle physics and is used in a wide variety of neutrino experiments to observe the secondary charged particles created after neutrino interaction. In this thesis, we consider two ways to improve both the simulation of Cherenkov light and the design of devices for its detection.

  First, we examine the approximation of the Cherenkov light coherent emission along the whole track of a charged particle used by the MC simulation tools, Geant4 in particular. We use a more physically accurate scattering model to precisely simulate particle propagation in a medium and calculate the Cherenkov light profile as the interference of the electromagnetic waves. We conclude that the Cherenkov radiation is coherent when electrons with energies down to 0.3 MeV travel in water, but a choice of a scattering model used for the simulation significantly changes the angular distribution of the emitted Cherenkov light. As a result, we develop a new Cherenkov radiation model for MC simulations and tune it in the 2.2 - 6.1 MeV energy range using SNO+ calibration data obtained from AmBe and $^{16}$N radioactive sources. With this model we resolve a previously observed tension in the isotropy of the Cherenkov light in SNO+, significantly improving how the simulation describes the data.

  With future Cherenkov detectors in mind, we also develop a simulation to assist in the design of silicon photomultipliers (SiPMs). The specific goal is to reduce the level of optical crosstalk (OCT) in the devices. The code is verified by comparing the obtained crosstalk levels to data from two SiPMs Hamamatsu VUV4 and FBK HD3 SiPMs. The code will be used to find the optimal geometry parameters to minimize OCT levels of possible future SiPM designs that will be capable of better light detection.

• Subjects / Keywords

  • Cherenkov light
  • SiPM
  • Scattering

• Graduation date

  Fall 2022

• Type of Item

  Thesis

• Degree

  Master of Science

• DOI

  https://doi.org/10.7939/r3-aprz-7k60

• License

  This thesis is made available by the University of Alberta Library with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.