Strip detector for short-range particles

A silicon strip detector for the coordinate determination of the short-range charged particles, particularly heavy ions, has been developed and investigated. The detector had 28 p/sup +/n strips made by ion implantation; the pitch was 250 mu m; and the interstrip distance was 50 mu m. The coordinates of particles incident between adjacent strips were determined by two-dimensional amplitude analysis of the charges collected on neighboring strips. Irradiation with alpha -particles of /sup 226/Ra and a scanning laser beam were used. A coordinate determination accuracy of better than 1 mu m was obtained. In contrast to minimum ionized particles, the plasma tracks of short-range particles have higher carrier densities and are located in the inhomogeneity region of the detector. A study of the charge collection times indicates the essential role of the drift of charges in the nonuniform electric field depending on the detector geometry, inhomogeneity of silicon, and built-in charge in the passivating oxide layer between p/sup +/n strips.<
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