Neutronics Calculations in Pellets and Blankets of Laser Fusion Reactor Concept SENRI-I

Abstract

The neutronic properties of SENRI-I, a reference design of laser fusion reactor proposed by Institute of Engineering, Osaka University, are discussed on the basis of the one-dimen-sional neutron transport calculations in burning DT plasmas and blankets. The softening of the fusion neutron energy spectrum, the neutron heating and the neutron multiplication are studied and discussed for the compressed DT pellets with various thickness of fuel plasmas and lead or lead-polyethylene tampers. The neutronic and thermal features in the blanket of the SENRI-I design are also examined. The tritium breeding ratio is high enough (1.6), depending on the neutron energy spectrum from a pellet. The maximum temperature increase per 1, 000 MJ DT fusion reactions is 3°C in the inner liquid Li layer and 1.5°C in the stainless steel first wall. A parametric study is also presented on the effect of varying the thickness of the inner Li blanket ΔR_i to examine the thickness required for the enough tritium breeding ratio and energy deposition.