Measurement and Calculation of Recoil Ranges of 27Mg and 24Na in the Reactions27Al(n, p)27Mg and 27Al(n, α)24Na

摘要

Since aluminum is widely used in reactor construction, the recoil ranges of 27Mg and 24Na produced by the (n, p) and (n, α) reactions play an important part in evaluating the amount of activity in the coolant of swimming pool type reactors. These recoil ranges however do not seem so far to have been studied in any great detail. Acrylic acid resin vessels containing aluminum sheets immersed in water were irradiated in the H.T.R. (Hitachi Training Reactor), after which the activity from the water was measured by β-γ coincidence. Background activity was determined by preparing blank water samples in which aluminum sheets were soaked for the same time interval without irradiation. Argon-41 activity was corrected by taking the decay curves from each of the coincidence channels. Aluminum foils were also irradiated dry and counted to determine the reaction rate. Recoil ranges of 27Mg and 24Na thus determined were 4.18×10-5 cm and 1.37×10-4 cm respectively, which agreed well with calculated values.