Simulation studies for a high resolution time projection chamber at the international linear collider

The International Linear Collider (ILC) is planned to be the next large accelerator. The ILC will be able to perform high precision measurements only possible at the clean environment of electron positron collisions. In order to reach this high accuracy, the requirements for the detector performance are challenging. Several detector concepts are currently under study. The understanding of the detector and its performance will be crucial to extract the desired physics results from the data. To optimise the detector design, simulation studies are needed. Simulation packages like GEANT4 allow to model the detector geometry and simulate the energy deposit in the different materials. However, the detector response taking into account the transportation of the produced charge to the readout devices and the effects ofthe readout electronics cannot be described in detail. These processes in the detector will change the measured position of the energy deposit relative to the point of origin. The determination of this detector response is the task of detailed simulation studies, which have to be carried out for each subdetector. A high resolution Time Projection Chamber (TPC) with gas amplification based on micro pattern gas detectors, is one of the options for the main tracking system at the ILC. In the present thesis a detailed simulation tool to study the performance of a TPC was developed. Its goal is to find the optimal settings to reach an excellent momentum and spatial resolution. After an introduction to the present status of particle physics and the ILC project with special focus on the TPC as central tracker, the simulation framework is presented. The basic simulation methods and implemented processes are introduced. Within this stand-alone simulation framework each electron produced by primary ionisation is transferred through the gas volume and amplified using Gas Electron Multipliers (GEMs). The output format of the simulation is identical to the raw data from a real TPC including readout electronics. Not only detector effects, but also consequences of the reconstruction algorithms can be tested. The results achieved with the simulation are compared to data acquired with a TPC prototype. Good agreement can be reached between simulated and measured data. The framework is then used to carry out some exemplary studies to test the performance of a TPC at the ILC. This includes spatial, momentum and energy resolution. The detailed simulation of the amplification structure using GEMs allows to also address the issue of ion backdrift. The results are compared to the design goals of the TESLA TDR. In future developments, the simulation framework presented here could be used to obtain a parametrisation of the detector response, which can then be incorporated into full detector simulations. A realistic detector response for the simulated energy deposit in the active volume could be achieved