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

Abstract—Already in 1993, sawtooth-shaped p+ strips were proposed to diminish lateral diffusion in linear multi-anode sil-icon drift detectors. The sawtooth structure generates small electric fields directed parallel to the detector surface and per-pendicular 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 m, we have tested the confinement of electron clouds as a function of injected charge up to 5 106 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. Index Terms — Charge sharing, electron cloud confinement, multi-anode linear drift detectors. I