Gießen 2024 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

HK: Fachverband Physik der Hadronen und Kerne

HK 27: Instrumentation VI

HK 27.2: Talk

Tuesday, March 12, 2024, 18:00–18:15, HBR 19: C 1

Simulation and analysis of pixel cluster shapes in the ALPIDE monolithic active pixel sensor — •Fabian Königstein for the ALICE Germany collaboration — Physikalisches Institut Heidelberg, Germany

The ALPIDE chip, a CMOS Monolithic Active Pixel Sensor (MAPS), is the key component of the currently operating ALICE inner tracking system (ITS2). The ITS2 features good spatial resolution and detection efficiency, excelling at reconstruction of primary and secondary vertices, as well as detection of low momentum particles. ALPIDE is a digital sensor, meaning that only binary information is recorded about the passing of a particle: either a pixel records sufficient ionization charge or not. No information about the mass or energy or velocity of the particle is available. The possibility of involving the ITS2 deeper in particle identification, improving the overall performance is investigated. In this work I explore the possibility of using groups of pixels which recorded a hit, a so called pixel cluster, for rudimentary particle identification. For this, I utilize a simple theoretical model to simulate the charge diffusion and drift in ALPIDE sensors and to understand how they affect the pixel cluster properties. The model is tuned to data recorded during ALPIDE beam test campaigns. Additionally, data for different particle species is compared to the corresponding simulation result to verify the simple model.

Keywords: simulation; pixel; diffusion; beam; particle