Natural II-a type diamond is increasingly used for the fabrication of radia
tion detectors. However, the presence of inherent defects has a strong impa
ct on the detector characteristics such as the time-dependent stability of
the detection signal. In order to draw better insight into this effect, com
parative investigations of the x-ray responses with thermally stimulated cu
rrent (TSC) measurements were carried out on natural diamond detectors. TSC
revealed the presence of four peaks or shoulders on natural samples in the
200-500 K domain. Three energy levels were identified at about 0.7, 0.71,
and 0.95 eV. Time-dependent x-ray detector sensitivity was investigated for
various initial conditions. The results give evidence of the improvement o
f the detection properties after having filled traps in the material by x-r
ay irradiation. The comparison between the x-ray response and the TSC spect
ra indicates that trapping levels emptied at room temperature appear to sig
nificantly affect the performance of radiation detectors. (C) 2000 American
Institute of Physics. [S0021-8979(00)06706-2].