Flat Helical Delay Lines for Position Readout along the Anode Wire in MWPC and Drift Chambers

Simple, flat helical delay lines were developed for avalanche position determination along each anode wire, for unambiguous readout of multiparticle events in multiwire drift or proportional chambers. Lines of various propagation delay and dimensions were tested with x-rays and ß-rays in several gas mixtures. Avalanche position resolutions of 0.2 mm and 0.6 mm FWHM, respectively, were obtained with a line 30 cm long in non electron-attaching gases.