Andrea Fodor ; Andreas Warburton

2017
McGill University Montreal

Abstract: The upgrade of the KEKB to the SuperKEKB accelerator is being followed by the update of the Belle detector to the Belle II detector. The design instantaneous luminosity of SuperKEKB is 8$\cdot$10$^{35}$~cm$^{-2}$s$^{-1}$, forty times higher than that at KEKB. The new high-luminosity environment will bring an increase in the beam background. Due to the 40-fold increase in luminosity, the beam backgrounds are expected to increase also by forty times compared to those encountered by the Belle experiment. The Belle II collaboration has implemented various countermeasures to combat the increase in beam background and enable a safe operation of the Belle II detector. A beam background monitoring system was needed for measuring the background levels in the vicinity of the electromagnetic calorimeter endcaps. The system will need to be sensitive to both the fast changing injection background and the more slowly changing DC-like background during regular collider operation. The focus of this thesis is the motivation of the design and technologies used for the background monitoring system. The existing background simulation for the calorimeter was analyzed in preparation for the beam background monitors' design. The monitors are to be placed in recesses located in the forward and backward endcap shields. LYSO scintillating crystals read out by Hamamatsu R7761-70 photomultipliers will be used for detection. The background monitors were included in the background simulation, which was used to estimate the energy deposition they will be receiving.

Note: Presented on 23 03 2017
Note: MSc