Differences in the microstructure of the F82H ferritic/martensitic steel after proton and neutron irradiation

The microstructure of the F82H steel that is a candidate for the future fus ion reactor first wall is investigated. Protons as well as fission neutrons are used to simulate the irradiation effects of the fusion environment. Th e differences in the He production rates between the two types of irradiati on may lead to differences in the irradiation damage of the F82H microstruc ture. This paper presents a transmission electron microscopy (TEM) study fo r three different irradiation conditions: (i) in the PIREX facility with 59 0 MeV protons, (ii) with fission neutrons at the research reactor in Petten and (iii) with 590 MeV protons in PIREX followed by fission neutrons at th e reactor in Studsvik. The latter experiment allows us to vary the He produ ction rate for a given irradiation type. Total doses ranged from 0.3 to 10 dpa and temperatures ranged from room temperature to 310 degreesC. (C) 2000 Elsevier Science B.V. All rights reserved.