Speaker
Description
The combination of a pixelized, high-granularity readout Application-Specific Integrated Circuit (ASIC) with a gaseous amplification stage enables various possibilities for particle physics experiments. Examples include the tracking of low-momentum particles, which requires a low material budget; X-ray polarimetry; and rare-event searches that benefit from selecting events based on their geometrical shape.
Starting from the Timepix, which was originally developed to read out Time-Projection Chambers (TPCs), an entire family of hybrid silicon pixel ASICs has been developed that is widely used for the readout of gaseous detectors. The latest version, Timepix4, provides a significantly larger area than its predecessors (7 cm² vs 2 cm²), square pixels with a 55 µm pitch, and a time resolution of < 200 ps.
A prominent example of a gaseous detector with Timepix readout is the “GEMPix”, where a triple-GEM stack is used for signal amplification and the open bump bond pads of the Timepix, typically used for a semiconductor sensor, serve as charge collection pads. In the last years, we have built the latest version in the GEMPix family, the GEMPix4.
In this presentation, we will review the GEMPix4 prototype design and discuss some of its (possible) applications, including those outside of typical particle physics experiments, e.g., beam monitoring for radiation therapy. Furthermore, we will present results obtained with the latest GEMPix4 prototype, focusing on the advantages provided by the high-granularity readout. In one case, we demonstrate how to resolve tracks of 4.5 keV photoelectrons in a He/CO₂ mixture at ambient pressure. In another case, we present results from a test beam campaign conducted in May 2025, including operation in TPC mode, highlighting the individual ionization clusters along the particles’ trajectory through the detector.
| Name of the speaker | Lucian Scharenberg |
|---|---|
| Eligible for the Georges Charpak Young Scientist Award. | yes |