R&D of MPGD-readout TPC for the International Linear Collider experiment

A Time Projection Chamber (TPC) is chosen for the central tracker of the ILD detector, one of two detector concepts planned for the International Linear Collider (ILC). Physics goals at the ILC will require a TPC with a position resolution of 100 μ m and superior track separation, which are not achievable with a conventional Multi-Wire Proportional Chamber (MWPC) readout. A MPGD readout offers improved position resolution and track separation due to measuring the signal at the anode and minimization of E × B effect. For several years, the LC TPC collaboration has been developing a MPGD readout using various small TPC prototypes and the Large Prototype TPC that is operated in a test beam at DESY. The MPGD technologies being tested are GEM and Micromegas with resistive charge broadening, with both traditional pad and CMOS pixel readout. Readout modules with both GEM and Micromegas gas amplification have achieved a position resolution on the order of 100 μ m at B = 1 T. In this paper we report on the recent R&D toward the ILD TPC.