Time Projection Chambers with C-pads for heavy ion tracking

Time Projection Chambers with C-pads and integrated delay line readout were developed as position sensitive detectors for the Fragment separator at GSI Darmstadt. The main advantages of TPCs are a small amount of matter in the sensitive volume, high spatial resolution, and high tracking efficiency. Working parameters in experimental conditions are presented. Internal spatial resolutions of sigma(x) = 88 mu m and sigma(y) = 38 mu m were achieved. The tracking efficiency dependence on ion beam intensity was studied with (238)U beam at 1 GeV/u energy. Efficiency of more than 99% was achieved up to 40 kHz and over 90% for 250 kHz (238)U beam intensity. Different kinds of ions from proton to uranium were measured in many experiments and confirmed the result obtained. (C) 2011 Elsevier B.V. All rights reserved.