Nuclear Seminar - Klára Ištoková, Benjamín Dutka (7.10.2026)
Wednesday 7.10.2026 at 14:00, Lecture room F1/364
Bc. Klára Ištoková:
Summer Internship – Event reconstruction of background photons using the Compton telescope method
and
Bc. Benjamín Dutka:
Summer Internship - Data Analysis of S1 and S2 Signals from AmC and AmBe Sources
Abstract No. 1:
MeV gamma imaging is of significant importance in nuclear astrophysics, medical imaging, and low-background rare-event searches. A Compton telescope reconstructs the incident direction of gamma rays by measuring the energy depositions and spatial positions of multiple Compton scattering interactions in the detector and applying Compton kinematics. PandaX is a dual-phase time projection chamber capable of precisely reconstructing both the deposited energy and the particle vertex, thereby enabling detailed studies of physical processes occurring within the detector. Therefore, PandaX naturally provides an excellent platform for studying Compton gamma physics. This issue was investigated during a one-month summer internship at Shanghai Jiao Tong University in China. Progress has been achieved in reconstructing the position of a background photon source by using spatial and energy-deposition information from multiple Compton scattering vertices, with the objective of eliminating the source. An analysis is provided on the findings and weaknesses of this technique. The study was performed under the guidance of Prof. Jianglai Liu.
Abstract No. 2:
The talk presents the detection principle of dark matter in the dual-phase liquid-xenon time projection chamber (TPC) of the PandaX-T experiment. We describe how the S1 (scintillation) and S2 (ionization) signals are used to discriminate between nuclear and electron recoils, and how energy and interaction position are reconstructed. The calibration strategy of the detector is then discussed, including external and internal sources (DD, AmC, AmBe) and the practical challenges encountered during the calibration process (extraction efficiency, gain stability, background noise and noise from electronics). Finally, we present the comparison of Monte Carlo simulations (primarily using the Geant4-based BambooMC framework) with measured data. The study was performed during a month-long summer internship at Shanghai Jiao Tong University in China, under the guidance of Prof. Ning Zhou.