Development of Time Projection Chamber prototype integrated with UV laser tracks for the future circular e+e- collider

Abstract

The Circular Electron Positron Collider (CEPC) has been proposed as a Higgs and a high luminosity Z factory in the last few years.The baseline detector concept design consists of a Time Projection Chamber (TPC) as the main tracker detector, which needs the high precision spatial resolution of approximately 100 μm in rφ direction over the whole the drift length.There will be no power-pulsing mode in the future circular colliders, the specific limitations of the detector requirements should be considered at the high luminosity Z pole.Several critical issues remain regarding the TPC R&D.The physics goals require particle identification (PID) resolution to be considered using the cluster counting method.The updated simulation results of the PID resolution demonstrate the potential of TPC technology to fit Z-pole running at CEPC.To meet the physics requirements for the tracker detector in CEPC, a TPC prototype integrated with an ultraviolet laser track system has been developed.The prototype consists of several horizontal laser tracks around the TPC detector chamber with a drift length of 500 mm, the fast electronics readout of 1280 channels, a 20000 V field-cage, a double-layer GEM detector with 200 × 200 mm2 active area and a DAQ system.The spatial resolution, dE/dx resolution, and drift velocity were studied and analyzed using the TPC prototype and the 266 nm UV laser tracks.Some updated experimental results, including the spatial resolution, the laser track reconstruction, and dE/dx resolution have been obtained.By using the pseudo full-length track to evaluate the full-size TPC with 220 layers at CEPC, the dE/dx resolution was estimated to be about 3.4%.All results indicates that this TPC prototype integrated with UV laser tracks has been successfully developed to meet the updated CEPC physics requirements.