Express measurement of the 7Li(n,n'α)3H reaction rate in a hybrid blanket model of a thermonuclear reactor

The experimental studies of neutron-physical characteristics of blanket models of thermonuclear reactors for improvement of calculational programs and correction of group constants include measurement of the rate of tritium formation in lithium-containing materials. The ratio of spatial distribution of the rate of 7Li(n, n*α)3H and 35Cl(n, α)32P reactions was measured in the experiments. Constancy of the measured ratio is the confirmation of equal sensitivity of the reactions to blanket neutrons. Li2CO3 detectors with following tritium registration by the method of liquid scintillation were used for direct measurement of 7Li(n, n*α)3H reaction rate. The rate of the 35Cl(n, α)32P reaction was measured by means of NH4Cl detectors using detection of Cherenkov radiation of 32P β-particles in water. The obtained constancy of the mentioned ratio permits to apply 35Cl(N, α)32P reaction for evaluation of the rate of tritium formation; in this case time of experiment duration with account of the obtained values of effective cross sections and half-life of tritium and phosphorus nuclei decreases approximately 100 times