Low-level gamma-ray spectrometry for analysing fusion plasma conditions

Abstract A new method, combining activation by neutrons and charged particles with ultra low-level gamma-ray spectrometry, aimed at obtaining a better understanding and more adequate measurements of MeV particle leaks in magnetic fusion devices was studied here. A total of 36 samples containing Ti, LiF, B 4 C and W were placed in a boron-nitride holder mounted on the ceiling of the JET Tokamak. The samples were activated by 63 pulses from a D– 3 He plasma and were later measured using underground gamma-ray spectrometry. The radionuclides 7 Be, 46 Sc, 54 Mn, 56 Co, 57 Co, 58 Co, 124 Sb, 181 Hf, 182 Ta, 181 W and 185 W were detected in several of the samples, with very low levels of activity …