Construction of a time projection chamber as focal plane detector for MAGIX and preparation of the hoyle state measurement at MAGIX

Abstract

As part of the PRISMA++ Cluster of Excellence, a new electron accelerator is currently being constructed at the Institute for Nuclear Physics at the Johannes Gutenberg University. This Mainz Energy-recovering Superconducting Accelerator (MESA) will host three experiments, whose goal it is to further our understanding of several areas of modern particle, nuclear, hadron, and astrophysics. The innovative part of MESA is its capability to recapture part of the energy of the beam once it has passed an experiment. To fully utilise this capability, any experiment has to be designed with consideration of the requirements for the recapture. This has been done for the Mainz Gas Injection Target Experiment(MAGIX), which has been designed to be operated in an energy recovery mode to support beam recapture. MAGIX is in line to be the first experiment in the world to have a measurement run using this breakthrough technology. To achieve this MAGIX employs a gas-jet target and will be run with no additional material in the beam or path of the scattering electron, minimising energy and precision loss by avoiding multiple scattering. Utilising the 105 MeV beam at 1 mA beam current MAGIX aims to reach a luminosity of up to 1 × 1035 cm−2 s−1. The detectors for MAGIX consist of two magnetic spectrometers which can rotate around the interaction point and which host two detector systems each: a focal plane trackingTime Projection Chamber(TPC), and a scintillator based Trigger Veto System. With this setup, the focus is on areas that require very high precision high luminosity low energy data, one of which is the first planned experiment to be run at MAGIX, a measurement dedicated to the Hoyle State. The aim of this thesis is to show that MAGIX will soon be ready to take this data, with a specific focus on two major components, the simulation software and the focal plane detectors. As such, it is split into three parts. The first part will deal with MESA and MAGIX, and the varied physics programs that will be run at them. The second part deals with the focal plane TPCs of MAGIX by explaining the theory behind its construction, its major components and what has already been achieved with those components. The third part deals with the preparation for the first measurement to be done at MAGIX. These preparations consisted of acquiring and characterising the target, preparing the theory, and writing simulation and analysis software.