A multi-electrode two-dimensional position sensitive diamond detector

Abstract

In multi-electrode devices, charge pulses at all the electrodes are induced concurrently by the motion of the excess charge carriers generated by a single ion. This charge-sharing effect is such that the pulse amplitude at each sensitive electrode depends on the device geometry, its overall electrostatic configuration, and the charge transport properties of the detecting material. Therefore, the cross-analysis of the charge pulses induced at each electrode offers implicit information on the position of the ion impact. In this work, we investigate the two-dimensional position sensitivity of a diamond detector fabricated by deep ion beam lithography. By exploiting the ion beam induced charge technique, the device was exposed to a 2 MeV Li+ ion micro-beam to map the spatial dependence of the charge collection efficiency (CCE) on the nominal micro-beam scanning position. The combination of the CCE maps revealed a two-dimensional position sensitivity of the device with micrometric resolution at the center of the active region.