Diminished electron cloud broadening in a silicon drift detector by sawtooth p/sup +/ strips

Abstract

Already in 1993, sawtooth-shaped p/sup +/ strips were proposed to diminish lateral diffusion in linear multi-anode silicon drift detectors. The sawtooth structure 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 present for the first time experimental proof of the applicability of the concept. For a sawtooth period of 500 /spl mu/m, we have tested the confinement of electron clouds as a function of injected charge up to 5/spl times/10/sup 6/ electrons. The maximum number of electrons for which full confinement is achieved has been measured as a function of the potential gutter depth generated by different sawtooth angles.