Münster 2017 – scientific programme
Parts | Days | Selection | Search | Updates | Downloads | Help
T: Fachverband Teilchenphysik
T 30: Elektroschwache Wechselwirkung 2
T 30.6: Talk
Tuesday, March 28, 2017, 12:15–12:30, JUR 372
Building a Tracking Detector for the P2 Experiment — •Marco Zimmermann for the P2 collaboration — Institute for Nuclear Physics, Johannes Gutenberg University, Mainz — PRISMA Cluster of Excellence
The P2 Experiment aims to measure the weak mixing angle at low Q2 via the parity violating assymetry in elastic electron-proton scattering. It will be located at the new Mainz Energy Recovery Superconducting Accelerator (MESA), which will provide a 150 µA beam of alternatingly polarized 150 MeV electrons.
While the main asymmetry measurement is performed with integrating Cherenkov detectors, the tracking system is developed in order to determine the average momentum transfer of the electron and to reconstruct individual electron tracks for systematic studies. It will be built using the new technology of High Voltage Monolithic Active Pixel Sensors (HV-MAPS) made of silicon thinned to 50 µm. Each of the tracking layers is envisaged to have a disc-like geometry. They are arranged as two double layers.
The high signal and background particle rates are the main challenge for the tracking system. The expected rate of electrons that are scattered in the liquid hydrogen target and hit the tracking system is of the order 105mm−2s−1 and is overwhelmed by partly more than 107 mm−2s−1 bremsstrahlung photons. Background particle rates of photons and other secondary particles are analysed in a Geant4-based Monte-Carlo simulation. In addition, measurements of the sensor response to photons are presented and compared to the simulation.