The primed state of CVD diamond under blue light illumination

The primed state of a detector grade CVD diamond sample has been investigated with respect to light illumination during alpha particles (5.5 MeV) detection. The measurements have been carried out as a function of elapsed time after beta-rays priming both in short term (1 h) and in long term (33 h) conditions. The contribution of holes and electrons to the average charge collection efficiency and to total number of counts above a threshold has been qualitatively separated by selecting bias polarity. The behaviour of electron collection after X-ray priming during blue light or UV illumination is improved while the hole one is worsened, confirming previous data. Linearity of the average collection efficiency for alpha particle is observed only at very low doses and in the hole case. Long term stability of both collection efficiency and of total number of counts is observed both in the primed state for holes and during blue light illumination for electrons.