Development and testing of an active shielding for SIDDHARTA-2

Abstract

The SIDDHARTA experiment investigated the low-energy strong interaction with strangeness, employing kaonic hydrogen and kaonic deuterium. The experimental observables are the 1s state shift and width of these atoms. The acronym SIDDHARTA stands for Silicon Drift Detector for Hadronic Atom Research by Timing Application.<br />The experiment on kaonic hydrogen was successfully performed in 2009.<br />However, the kaonic deuterium measurement suffered from low signal strength and a high background signal. To take a step further SIDDHARTA-2 should correct these insufficiencies with better shielding and other improvements. The experiment will be conducted in 2013/2014.<br />The goal of this diploma thesis is to provide a solution for the reduction of the hadronic background with an active shielding mechanism.<br />This will be located around the SDD x-ray detector ring and should be accomplished in a preferable simple and low cost apparatus. This ring-shaped detector arrangement will consist of scintillation counters providing the largest detection area possible and is read-out by solid state photo detectors (SiPMs, See 2.2 ).<br />The SIDDHARTA setup is mounted inside a vacuum chamber, therefore the shielding has to work in such an environment. Furthermore at least hundred SiPMs have to be powered and read out, so a small preamplifier with power source has to be developed. In this diploma thesis, different power source types are tested, as well as various scintillator shapes and SiPM characteristics.