A Multiwire Proportional Counter with Integral Readout Delay Line

A new concept for delay line readout of multiwire proportional counters for detecting the position of ionizing particles is described. It significantly reduces the complexity and cost of a multiwire system compared to alternative methods, making it attractive for space flight applications. This integral delay chamber can provide spatial resolution approaching 0.1 mm using Fe55, provided careful consideration is given to geometrical parameters that determine delay line bandwidth and phase distortion. For a chamber of 35 by 35 cm2 a delay of 20 ns/cm and attenuation of 0.05 dB/cm has been obtained. The delay line characteristics and electronic resolution, using a peak detection method, are given as a function of chamber geometry.