Investigation of natural diamond detector priming effect during electron beam irradiation

The internal polarization effect, produced in a PTW natural diamond detector under electron beam irradiation, was investigated as a function of the applied electric field. It emerged that a space–charge distribution was created in the sensitive volume by positive and negative trapped charge carriers both for positive and negative external polarizations. Analyzing the behaviour of measured photocurrents under different conditions, an average internal electric field equal to 90% of the applied electric field was obtained. The detector’s internal polarization produced a decrease in the charge collection efficiency between 50% and 70% within the range of the applied electric fields utilized (0.19–3.85 kV cm−1). In the end, a new method for the suppression of the internal polarization is compared with other methods reported in literature.