Diminished electron cloud broadening in a silicon drift detector by sawtooth p(+) strips

Already in 1993, sawtooth-shaped p(+) strips were proposed to diminish late ral diffusion in linear multi-anode silicon drift detectors. The sawtooth s tructure generates small electric fields directed parallel to the detector surface and perpendicular to the drift direction. These fields confine the drifting electrons within a sawtooth period. In this paper the authors pres ent for the first time experimental proof of the applicability of the conce pt. For a sawtooth period of 500 mu m, we have tested the confinement of el ectron clouds as a function of injected charge up to 5 x 10(6) electrons. T he maximum number of electrons for which full confinement is achieved has b een measured as a function of the potential gutter depth generated by diffe rent saw-tooth angles.