R &D of Time Projection Chamber for Particle Tracking

The Time Projection Chamber (TPC) has the capability of three-dimensional particle tracking. We are developing a bulk Micromegas based prototype TPC at SINP. In the present work, we have measured the detector gain, energy resolution, and electron transparency of the 128 um Micromegas in argon-based gas mixtures to optimize the operating drift and amplification field. We have observed the Fe55 spectrum in the argon-CO2 gas mixture with volumetric ratio of 90:10. We have found that the photo peak of Fe55 can be resolved with 100 V/cm drift and a 38 kV/cm amplification field in a test box. We have also calculated the effective drift field from a finite element field solver named COMSOL. We have used a drift field of 113 V/cm along the central axis of the prototype TPC and a 38.28 kV/cm field in the amplification region of the Micromegas detector to observe the Fe55 X-ray source photo peak spectrum in the prototype TPC. This is a preliminary result and proof of concept that our TPC is working. In the future, we will make a segmented anode to observe the alpha particle tracks with pure helium, methane, and isobutane gas.