Speaker
Description
GGas Electron Multipliers (GEMs) are widely used in high-energy physics experiments for charged-particle detection in high-rate environments, where detector optimization is essential for achieving high performance and long-term stability. In this work, we investigate the combined impact of GEM-hole geometry and transfer-gap configuration on the performance of GEM detector. Electric-field maps generated using ANSYS are interfaced with Garfield++ to simulate electron transport, avalanche multiplication, and ion motion in an Ar/CO2 gas mixture. Two GEM-hole geometries are studied: the standard bi-conical design and an optimized single-conical design. Detector response is evaluated for electrons (e), muons (μ), pions (π), kaons (K), and protons (p) using primary ionization modeled through the Bethe-Bloch formalism. In addition, the second transfer gap is systematically varied while keeping all applied voltages fixed to investigate its influence on charge amplification and ion transport.
The results reveal systematic variations in detector response with different particle species and incident energy, driven by differences in primary ionization. A clear correlation between effective gain and ion backflow is observed across all particle species. Notably, the optimized single-conical GEM geometry achieves a robust ~54\% reduction in the ion-backflow-to-gain ratio while maintaining consistent gain performance over a wide energy range. Furthermore, optimization of the second transfer gap identifies operating conditions that provide an improved balance between high gain and ion-backflow suppression. These findings demonstrate that combined optimization of GEM-hole geometry and transfer-gap length can significantly enhance detector stability and performance, providing valuable insight for future high-rate GEM detector applications.
| Name of the speaker | Poojan Angiras |
|---|---|
| Eligible for the Georges Charpak Young Scientist Award. | yes |