Performance Monitoring of the Barrel Time-of-Flight Supermodule for the PANDA Experiment at FAIR

The PANDA experiment at FAIR in Darmstadt will use proton-antiproton collisions, with momenta ranging from 1.5 GeV/c to 15 GeV/c, on a fixed target to study open questions in hadron physics. The Barrel Time-of-Flight detector for this experiment is a scintillating tile hodoscope based on 16 identical and independent subdetectors called Super-Modules arranged in a cylindrical configuration. We have conducted performance studies on one such Super-Module to prove the feasibility of the Barrel Time-of-Flight detector design. Time resolution, signal delay and amplitude drop along the length of the detector were measured and analyzed as a function of the position on the individual scintillator tiles. A time resolution of about 50 ps has been achieved, which is very important for event timing and particle identification.

Track Finding for the PANDA Detector Based on Hough Transformations

The PANDA experiment at FAIR (Facility for Antiproton and Ion Research) in Darmstadt is currently under construction. In order to reduce the amount of data collected during operation, it is essential to find as many true tracks as possible and to be able to distinguish them from false tracks. Part of the preparation for the experiment is the development of a fast online track finder. This work presents an online track finding algorithm based on Hough transformations, which is comparable in quality and performance to the currently best offline track finder in PANDA. In contrast to most track finders the algorithm can handle the challenge of extended hits delivered by PANDA’s central Straw Tube Tracker and thus benefit from its precise spatial resolution. Furthermore, optimization methods are presented that improved the ghost ratio as well as the speed of the algorithm by 70 %. Due to further development potential in terms of track finding for secondary particles and speed optimization on GPUs, this algorithm promises to exceed the quality and speed of other track finders developed for PANDA.

Track Reconstruction with PANDA at FAIR

The future PANDA experiment at FAIR aims to investigate a wide range of physics processes in antiproton-proton collisions at rates of up to 20 MHz, while employing a purely software-based event filter. To educate the trigger decisions, a full event reconstruction has to be carried out in real time. This challenge is amplified when considering tracks from particles with long lifetimes and displaced decay vertices, which add to the complexity of the reconstruction algorithms. Here, we present modifications to a cellular automatonbased track finder taking detector time-stamps into account in addition to spatial information, as well as several pattern recognition methods for longitudinal track reconstrucion with PANDA’s Straw Tube Tracker.

Study of the space charge effect in straw tube detectors for the PANDA experiment

The straw tube detectors in the PANDA experiment will work in high particle fluxes reaching up to 25 kHz/cm2. We performed measurement of the gas gain drop in the PANDA straws due to the space charge effect expected at the high particle fluxes. The applied experimental method and obtained results are presented and are compared with calculations of the gas gain drop based on known mobility of positive ions.