Performance of semiconductor radiation sensors for simple and low-cost radiation detector

Tanimura, Yoshihiko   ; Birumachi, Atsushi; Yoshida, Makoto; Watanabe, Tamaki*

In order to develop simple but reliable radiation meters for the general public, photon detection performances of radiation sensors have been studied both experimentally in photon calibration fields and by Monte Carlo simulations. A silicon photodiode and a CdTe detector were selected for the low-cost sensors. Their energy responses to ambient dose equivalent H(10) were evaluated over the energy range from 60 keV to 2 MeV. The response of the CdTe decreases markedly with increasing photon energy. On the other hand, the photodiode has the advantage of almost flat response above 150 keV. The sensitivities of these sensors are 4 to 6 cpm for the natural radiation. Detection limits of the radiation level are low enough to know the extreme increase of radiation due to emergency situations of nuclear power plants, fuel treatment facilities and so on.