Radiation measurements from Alcator C-Mod initial operation

Operation of the Alcator C-Mod experiment, a compact high field tokamak, resumed in April, 1993. This experiment is ultimately expected to produce neutron rates of 5×10¹⁵ n/s for 1 second long pulses at 20 minute intervals. The radiation detection system is comprised of a number of components for examination of specific aspects of the resulting ionizing radiation fields. Six fission detectors and 2 BF₃ counters which are mounted inside two moderator stations are used for detecting the global neutron production on each shot. Environmental thermoluminescent detectors (TLD´s), sensitive to both neutrons and γ-rays, are placed at distributed points both inside and outside of the facility. Self-reading dosimeters (SRD´s), neutron bubble dosimeters, and film badges are also used to check the daily and monthly radiation production. Portable instrumentation capable of integrating the radiation signals from short pulse operation is available in order to survey biological shield penetration leakage. Tracerlab area monitors have been installed to measure the activated background levels in the test cell. Details of these systems are discussed, and the initial measurement results are presented