Drift field improvement and test in a GEM-TPC prototype

With the help of Maxwell,Ansys and Garfield,a simulation of the electric field and the deviation of electron drift in the drift volume of a GEM-TPC prototype has been accomplished under the following conditions:Field Cages with one-side and double-side strips,with and without a guard ring.The advantage and necessity of a Field Cage with mirror strips and a guard ring were foreseen.According to the simulation results,TU-TPC was modified and tested;a larger effective area and better resolution were achieved.