Coaxial and Printed Circuit Delay Lines for Multi Wire Proportional Chamber Readout

Delay lines have been shown to offer many advantages for multi-wire proportional chamber readout, particularly in applications involving single event counting. It is desirable to optimize the delay line with respect to cost, mechanical convenience, linearity, and risetime. We have constructed several types of tapped delay lines and have tested them with a 20 × 20 cm proportional chamber. A delay line constructed of 100 1 meter lengths of RG-316/U miniature coaxial cable offers excellent linearity (< .2%), a rise time of 30 nsec, and total delay of 500 nsec. Printed circuit delay lines, with characteristics similar to the coaxial lines were constructed, and offer greatly improved packaging properties at a cost of less than $ 1 per wire.