New technique using room temperature diodes for the direct assessment of internal contamination by low energy gamma-ray emitters.

Silicon PIN diodes were tested as direct detection elements for in vivo counting. They have a low sensitivity to background radiation in the energy range below 80 keV so that they can be used outside a shielding room for the measurement of weakly absorbing organs or tissues in cases of incorporation of fuel particles and medical radionuclides. Results are reported on the spectral characteristics of these detectors. Comparison with other techniques is examined. This paper describes a novel technique of in vivo counting which needs no shielded room and which is applicable to other types of room temperature detectors. The concept of wearable counting devices is presented with description of their design.