Responses of alanine dosimeters to irradiations at cryogenic temperatures

Present and future high-energy accelerators and particle detectors use and will use super-conducting technologies where components are submitted to radiation in a cryogenic environment. Radiation tests and dosimetry calibration have to be made under these conditions. Alanine-ESR dosimetry is world-wide recognised as a standard method for high-dose measurements at room-temperature irradiation. From earlier work, the system also seems suitable for low-temperature applications, despite a decrease of sensitivity. The aim of the present work was to estimate the temperature dependence of five different alanine based dosimeters. The dose-response functions at 290, 77 and 5 K were determined between 10 Gy and 80 kGy. All the results were consistent among the five laboratories: at a given dose, the amplitude of the ESR signal decreases with the irradiation temperature, moreover, this effect is found to be dose-dependent.