SUPRALINEARITY AND LET DISCRIMINATION IN RADIATION MEASUREMENTS

Abstract

According to track theory, detectors whose response to gamma rays is supralinear will inherently discriminate against low LET in favour of high LET radiations, especially at low dose, while detectors whose response is linear or exponential exhibit the reverse discrimination. The detailed characteristics of these discriminations can be calculated once the radiosensitivity parameters of the detector are known. If both one hit (exponential) and c-hit (supralinear) detectors are exposed to the same radiation field, the complimentary discriminations can be used to sort out the low and high LET components of the radiation field. An even more interesting discrimination may be possible. For if the detector parameters are appropriately chosen, they may be able to reflect the discriminations made by biological tissue, for inactivation in the gamma kill mode (the low LET response) and in the ion kill mode (the high LET response).