Reduction in non-linearity in position-sensitive MWPCs

Measurements of differential nonlinearity have been made with a small multiwire proportional chamber (MWPC) for two special cathode strip geometries. The results have been compared with those for conventional strip geometry and with theoretical predictions. With the ratio of sampling node separation to anode-cathode check separation at the exceptionally large value of 2.4, a peak-to-peak differential nonlinearity of 72% was observed for the conventional geometry. The first special geometry used two intermediate strips between the readout strips, with near optimum capacitive coupling between them, to achieve a differential nonlinearity of about 4% at the same ratio of 2.4. In the second special geometry, cathode strips with optimum-depth zigzag-shaped boundaries yielded an experimental differential nonlinearity of about 7%