Measured Characteristics of Be Multi-Layered and Coolant Channel Blankets: Phase IIC Experiments of the JAERI/USDOE Collaborative Program on Fusion Neutronics

Two types of heterogeneous blanket systems were tested to estimate a design margin for neutronic calculations. One system simulates a multi-layered beryllium/lithium-oxide blanket, and the other does water coolant channels in a Li₂O blanket. For both systems the tritium production rate (TPR), reaction rate and neutron spectrum were measured. Those measurements were performed by NE213 and Li-glass scintillators, Li-foil and Li₂O zonal block scheme for TPR, activation foils for reaction rate and proton recoil proportional counters for spectrum. In addition, gamma-ray heating was measured by spectrum weighting function technique using NE213 scintillator. Precise distribution measurements near the material boundary were performed especially by directly stacking the irradiation samples in the test blanket region to minimize a perturbation for the measurement.