Authors:	Zimmermann, Marco
Title:	Particle Rate Studies and Technical Design Development for the P2 Silicon Pixel Tracking Detector
Online publication date:	21-Oct-2019
Year of first publication:	2019
Language:	english
Abstract:	The P2 Experiment intends to determine the weak mixing angle at low momentum transfer Q^2 by measuring the parity violating asymmetry in elastic electron-proton scattering. The targeted relative uncertainty on the weak mixing angle is 0.15 %. The experiment is at the same time a precision test of the Standard Model of particle physics and a search for New Physics at the intensity frontier. It will be carried out at the Mainz Energy Recovery Superconducting Accelerator (MESA), which will provide a 150 µA beam of alternatingly polarized 150 MeV electrons with excellent beam stability. While the parity violating asymmetry will be measured with integrating Cherenkov detectors, the tracking detector is developed to determine the four momentum transfer Q^2 of the electrons in the liquid hydrogen target, and to reconstruct individual electron tracks for systematic studies. The novel technology of High Voltage Monolithic Active Pixel Sensors (HV-MAPS) will be used in order to minimize the material budget and thus reduce multiple scattering. One main difficulty for the tracking detector design is the demand to minimize the material of the infrastructure needed for mechanical support, powering, readout and cooling of the sensors. Moreover, the rate of about 0.1 THz of electrons being scattered into the acceptance of the tracking detector is challenging for the data acquisition system and the radiation hardness of all used components. This work presents feasibility studies on the tracking detector of the P2 experiment. In the first part, the signal and background particle rates as well as the overall radiation load are estimated based on a detailed Geant4 Monte Carlo simulation. Photons represent the most abundant background type. The detection probability of photons is therefore further investigated in experimental tests. In the second part of this work, the technical design of a tracker module is worked out. The full tracking detector will consist of eight identical modules, each containing around 630 sensors of dimensions 2 cm x 2 cm that are arranged in two planes. A thermo-mechanical detector prototype has been constructed based on this design, demonstrating its feasibility. In this prototype, a flexprint with heatable copper traces is implemented as a mock-up of the actual sensors mounted on polyimide foil. The sensor cooling concept based on gaseous helium was integrated into the mechanical design and investigated in computational fluid dynamics simulations. The assembled prototype will allow to compare these simulations to experimental cooling tests.
DDC:	530 Physik 530 Physics
Institution:	Johannes Gutenberg-Universität Mainz
Department:	FB 08 Physik, Mathematik u. Informatik
Place:	Mainz
ROR:	https://ror.org/023b0x485
DOI:	http://doi.org/10.25358/openscience-2344
URN:	urn:nbn:de:hebis:77-diss-1000031258
Version:	Original work
Publication type:	Dissertation
License:	In Copyright
Information on rights of use:	https://rightsstatements.org/vocab/InC/1.0/
Extent:	xii, 258 Seiten
Appears in collections:	JGU-Publikationen