Development of a Time Projection Chamber Using Gas Electron Multipliers   (GEM-TPC)
  We developed a prototype time projection chamber using gas electron multipliers (GEM-TPC) for high energy heavy ion collision experiments. To investigate its performance, we conducted a beam test with 3 kinds of gases (Ar(90%)-CH4(10%), Ar(70%)-C2H6(30%) and CF4). Detection efficiency of 99%, and spatial resolution of 79 $\mu$m in the pad-row direction and 313 $\mu$m in the drift direction were achieved. The test results show that the GEM-TPC meets the requirements for high energy heavy ion collision experiments. The configuration and performance of the GEM-TPC are described. 
S.X. Oda, H. Hamagaki, K. Ozawa, M. Inuzuka, T. Sakaguchi, T. Isobe,   T. Gunji, Y. Morino, S. Saito, Y.L. Yamaguchi, S. Saw...