Application of the “MBWC” two-dimensional position readout technique to a multiwire proportional counter

A two-dimensional position readout technique named “modified backgammon method with weighted coupling capacitors (MBWC)” has been applied to a multiwire proportional counter, and its image linearity and position resolution have been investigated. One of two types of the technique, the three-output MBWC method, has shown several kinds of image deformations. The sources of the deformation and the way to avoid them are clarified. On the other hand, an essentially linear image has been readily obtained by adopting the other type (four-output MBWC method). The overall spatial resolution parallel to the wire direction and the spatial resolution of the position encoding cathode for the direction perpendicular to the wire have been investigated with Fe K X-rays. The best values obtained are 130 and 110 μm (FWHM), respectively, which correspond to ∼600 × 600 pixels.