Speaker
Description
Future circular e+e− colliders, such as the Future Circular e+e− Collider (FCC-ee) and the Circular Electron Positron Collider (CEPC), have been proposed as Higgs and Z factories in the international high energy physics community. In the ILD detector concept and comparable detector designs, a Time Projection Chamber (TPC) with high-precision (~100 μm) spatial resolution serves as the main tracking device inside a 3.0 T solenoidal magnetic field. The TPC is required to provide a standalone momentum resolution of 10⁻⁴ (GeV/c)⁻¹, and a particle identification (PID) resolution of better than 3% is required. While TPC performance is satisfactory for Higgs-mode operation, high-luminosity Z-pole running poses substantial technical challenges, requiring rigorous evaluation of the feasibility and corresponding mitigation strategies.
As a gaseous-detector R&D effort, this talk will present the feasibility study and recent progress of a high-precision TPC with Micro-Pattern Gaseous Detector (MPGD) readout for future e+e− colliders. To meet the PID requirement, the cluster-counting technique is being developed as the PID estimator, and simulation results of the pad-based and pixelated TPC readout technologies will be reported. Compared with the conventional pad readout, the high-granularity readout option (500 μm × 500 μm and TimePix chips) provides better single-electron spatial resolution, higher hit detection efficiency, and improved tracking and PID performance satisfying the 3% PID requirement. Furthermore, based on machine–detector interface (MDI) background simulations, ion-induced space-charge effects have been evaluated in detail, and the associated TPC technical challenges and potential mitigation strategies will be discussed, with emphasis on high-luminosity Z-pole running conditions.