Bereiche | Tage | Auswahl | Suche | Aktualisierungen | Downloads | Hilfe

T: Fachverband Teilchenphysik

T 61: Methods in Particle Physics III (Tracking)

T 61.2: Vortrag

Mittwoch, 2. April 2025, 16:30–16:45, VG 4.101

SciFi Threshold Calibration — •Dhruvanshu Parmar¹, Xiaoxue Han², and Mikhail Mikhasenko¹ — ¹Ruhr-Universität Bochum, Bochum, Germany — ²Ruprecht-Karls-Universität, Heidelberg, Germany

The Scintillating Fiber tracker (SciFi) at LHCb, operational since 2022, is the main tracker positioned downstream of the dipole magnet. Aided by upstream trackers, SciFi detects charged particles and precisely measures their momentum and trajectory with high accuracy. It consists of three stations, each composed of 5-meter high modules containing scintillating fiber mats. The ends of the tracker modules include readout boxes equipped with silicon photomultiplier sensors (SiPMs) that collect photons generated by particle interactions with the scintillating fibers. Analog signals from SiPM channels are processed by comparing them to a set of three "comparator" thresholds to discriminate signals from dark noise. Adjusting these thresholds is critical for a high hit efficiency, a low fake track rate and sustainable bandwidth. This talk summarizes the utilization of the Light Injection System (LIS) for calibrating the comparator thresholds for the full system of 524k SiPM channels and 1.5M comparators. Accurate time alignment for optimizing LIS performance and full calibration procedure of fitting SiPM spectra will be discussed. Finally, challenges faced with LIS calibration and strategies to address them will be highlighted.

Keywords: SciFi tracker; Threshold calibration; LHCb; Scintillating Fiber; SiPM Readout