The Proportional Inclined Chamber: First Results

Abstract

It was proposed by one of us (M.P.) to use a multiwire proportional chamber inclined with respect to the average direction of the tracks and to measure the drift times. If the chamber is inclined the number of wires interested by the passage of a particle is an increasing function of the angle between the normal to the chamber plane and the line of flight of the particle. Fig. 1 shows the field lines for a chamber with 2 mm wire spacing and 2x8 mm gap width; two tracks passing through and some drift routes are also shown. If the angle is large (i.e. 30°) the number of wires that give a useful signal is also large (5 or 6 in that case). By measuring all these drift times many independent measurements of the particle trajectory are obtained, improving the spatial resolution. The redundancy of the information helps to resolve complicated situations (nearby tracks for example) and to check the corrections for distortions etc.