AMS Transition Radiation Detector 4-Layer Prototype and Gas System Tests

The AMS Transition Radiation Detector (TRD) will provide a proton background rejection of 102-103 to search for SUSY dark matter signatures in the high energy cosmic rays spectrum. The TRD consists of 20 layers of straw proportional tubes interleaved with a eece radiator material. Each tube will be lled with a Xe:CO2 (80:20) mixture supplied by a gas system designed to operate for more than 3 years in space; the accuracy of the gas ratio is of fundamental importance for transition radiation detection. Functional tests of the gas system, together with the related electronics and control software, have been performed. In particular, studies of the mixing procedure, checks of the gas quality and tests performed on a TRD 4-layer prototype will be discussed.