Simulation and Reconstruction of Muon Tracks with the "multi-PMT Digital Optical Module" in Comparison to the "PINGU Digital Optical Module" for the IceCube-Gen2 High-Energy Array

• Main Author: Kittler, Thomas
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: 2020
• Subjects: ddc:530; Pingu; antartic*
• Online Access: https://opus4.kobv.de/opus4-fau/frontdoor/index/index/docId/14233; https://nbn-resolving.org/urn:nbn:de:bvb:29-opus4-142332; https://opus4.kobv.de/opus4-fau/files/14233/ThomasKittlerDissertation.pdf

The IceCube neutrino observatory is the largest operating neutrino telescope at the moment. It consists of 5160 Digital Optical Modules (DOMs) on 86 vertical strings buried in a depth of 1.5km to 2.5km within the Antartic ice instrumenting a volume of approximately 1 cubic km . An upgrade of the in-ice array to a volume of almost 10 cubic km, called IceCube Gen2 high- energy array, is the subject of current research. The multi photomultiplier (PMT) Digital Optical Module (mDOM), which consists of 24 symmetrically distributed 3-inch PMTs, is considered as detection unit for the Gen2 high-energy array. Alternatively, an upgraded version of the IceCube DOM, called PINGU Digital Optical Module (PDOM), containing only one 10-inch PMT facing downwards, is also considered as detection unit. This work analyzes the effect of the sensor segmentation of the mDOM on the angular resolution of through-going muon tracks in comparison to the angular resolution obtained with the PDOM within the context of a Gen2 high-energy array geometry. In order to eliminate the effect of different photon detection efficiencies of the two sensor designs, the quantum efficiencies of the respective PMTs are scaled in the simulation to ensure an equalized effective photocathode area per module. For down-going and horizontal through-going muons with an energy between 3TeV and 70PeV a detector equipped with mDOMs yields between 10% and 40% better angular resolution in almost all energy regimes after sensor-independent quality cuts (based on Monte Carlo information) have been applied. For up-going muons with energies below 1PeV the upscaled PDOM yields between 7% and 13% lower angular errors. Finally, estimations of the 90% exclusion limits and the 5σ discovery fluxes of neutrino point sources are conducted for both sensors in a Gen2 high-energy array. For sources with a declination below 5° the upper limits and discovery fluxes obtained with the mDOM are 8 − 11% lower. The upscaled PDOM leads to 4 − 12% lower exclusion limits and discovery fluxes ...