2025/05/19 by C. Lasaosa, Lasaosa, Clara, M. Fernández +11
Engineering · Physics and Astronomy · #CCD and CMOS Imaging Sensors #FOS: Physical sciences #High Energy Physics - Experiment (hep-ex) #Instrumentation and Detectors (physics.ins-det) #Particle Detector Development and Performance #Radiation Detection and Scintillator Technologies
paper · pdf · doi:10.48550/arxiv.2505.12857
openalex publication_date 2025/05/19 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/30
Three-dimensional (3D) pixel sensors are a promising technology for implementing the 4D-tracking paradigm in high-radiation environments. Despite their advantages in radiation tolerance, 3D pixel sensors exhibit non-uniform electric and weighting fields that can degrade timing performance. This study explores the impact of pixel cell geometry on the timing characteristics of 3D columnar-electrode sensors fabricated by IMB-CNM, comparing square and hexagonal layouts. The sensors were characterized using the Two-Photon Absorption Transient Current Technique (TPA-TCT), providing high-resolution three-dimensional maps of the Time-of-Arrival (ToA) of charge carriers. Measurements at multiple depths and bias voltages reveal that the square geometry yields a more uniform temporal response compared to the hexagonal configuration. Additionally, a novel TPA-TCT-based method was introduced to determine the sensor jitter, relying on the analysis of the time difference between consecutive pulses in the TPA-TCT pulse train acquired under identical conditions. These findings underline the importance of pixel design optimization for future 4D-tracking detectors and confirm the TPA-TCT method as a powerful tool for detailed timing characterization.