Self-supporting cylindrical multiwire proportional chambers with two dimensional read-out

Abstract Cylindrical MWPCs have been constructed with anode diameters of 240–430 mm and a length of 750 mm. Cathode strips run helically with 38°–61° to the anode wires, and the induced charges were read out by ADC. Both the anode and the cathode efficiency were well above 99%. The resolution (σ) for the longitudinal position of the avalanche was 0.6 mm by the centre of gravity method, if the cathode was read out per 12 mm width by summing two adjacent cathode strips.