A simulation of a CdTe gamma ray detector based on collection efficiency profiles as determined by lateral IBIC

Collection efficiency profiles as determined by the ion beam-induced charge (IBIC) technique have been considered to evaluate the spectroscopic perfor mance of a cadmium telluride (CdTe) nuclear radiation detector. The depende nce of such profiles on the applied bias voltage and the shaping time are p resented and discussed on the basis of a theoretical model, which is also u sed to evaluate the electron/hole collection lengths profiles. Experimental collection efficiency profiles were used as input data of the "ISIDE" Monte Carlo programme to simulate the CdTe response to gamma rays p roduced by Co-57. A systematic investigation of such spectra obtained under different detection conditions shows the effects of non constant collectio n efficiency profiles and ballistic deficit on the energy resolution of the detector. (C) 1999 Elsevier Science B.V. All rights reserved.