Speaker
Description
Future electron-positron colliders, such as CEPC, FCC-ee, and ILC, are being proposed for precision studies of the Higgs boson, electroweak physics, and flavor physics. These ambitious physics programs require excellent particle identification (PID) over a wide momentum range. The Time Projection Chamber (TPC), with its low material budget and excellent tracking capabilities, is the baseline main tracker detector for these colliders. With high-granularity readout and cluster-counting techniques, the TPC offers significant potential for achieving the demanding PID performance.
This poster presents recent studies on the PID performance and readout pad-size optimization for the CEPC-TPC. A full simulation chain, based on Geant4 and Garfield++, has been developed to model the TPC response from primary ionization to digitized signals. Using a layered truncated-mean algorithm, we systematically evaluate the π/K separation power as a function of pad size, demonstrating that a 500×500 µm² pad size achieves >3σ separation up to 20 GeV/c, while providing a balance between performance and engineering feasibility. In addition, we address the critical challenge of beam-induced background at high-luminosity operation. Our simulations show that the space charge effect, arising from accumulating positive ions, can significantly degrade the momentum resolution at the Z-pole. We present strategies to mitigate this effect, including MDI optimization, which is shown to substantially recover the TPC's intrinsic performance.
These studies provide essential input for the TPC design in future high-energy collider experiments and inform the development of robust operational strategies.
