Study of the neutron spectrum in the test section of fusion engineering test facility based on mirror confinement (FEF)

Abstract

Abstract The cylindrical plasma in the central cell of the mirror based fusion engineering test facility FEF is used as the 14 MeV neutron source for the fusion engineering tests. The tests are mainly irradiation tests to investigate the behavior of first wall materials and blanket components irradiated by 14 MeV neutrons. The irradiation tests which are assumed to be conducted in the FEF are as follows: (1) material irradiation tests, (2) tritium breeding tests, (3) blanket engineering tests, (4) integrated test under fusion reactor conditions. The following tests are also considered for utilization of the neutron source, (a) fissile fuel production test, (b) isotope production test, (c) nuclear waste annihilation test. The spatial distributions of the intensity of the neutron flux and its energy spectra and that of the gamma ray flux in the test section of FEF have been calculated by using the ANISN code. These calculations were needed to investigate the dependence of the neutron spectrum on the coolant materials of the first wall and the type of reflector. It was found that lead was an optimum choice for the reflector and that the total fluxes of the neutrons at the capsule and loop regions were 6.3 × 1014 n/cm2s and 5.4×1014 n/cm2s respectively. The flux in the capsule region could be as high as 1 × 1015 n/cm2s in the specially designed test section. The energy spectrum found was close to that of a commercial fusion reactor.