Proportional chambers with delay line readout in the MD-1 detector

A system of proportional chambers is described which was used in the MD-1 detector at the VEPP-4 collider for detection of scattered electrons in two-photon reactions. To obtain the necessary spatial resolution proportional chambers with delay-line readout have been used. The system contained 6 chambers of this type with a size of 500x200 mm2, during three years it was under operation with a counting rate up to 400 kHz per chamber. The long term spatial resolution was not worse than σ=0.2 mm. The energy resolution achieved was 1.3%. (orig.)