Performance of 2mm radius straw tube drift cells

The performance of a 128 channel test module made with straw tubes of 2mm radius has been studied in a test beam and with cosmic rays. Different gases were used and for each one the time-to-distance relation and the hit efficiency was measured. Comparison are made between results when two different electronics readouts were used. The information was recorded with 106 MHz FADC units and also with TDCs (50ps resolution). The best resolution, of 135 [mu]m, was obtained using 50% ethane, 50% argon and reading out the information with the TDCs, at an operating HV of 1,750V.