Helium generation in fusion reactor materials

The work performed under this giant included an analysis of the multiple-step helium production mechanism discovered in iron following long-term mixed-spectrum reactor exposure, the measurement of a large number of samples irradiated in fast-neutron environments for cross section determinations, the initial mapping of the neutron fluence distribution for a high-fluence T(d,n) irradiation experiment, the initial measurements of helium production in materials irradiated by 10-MeV neutrons, and the initiation of a joint experiment with ANL to measure the spectrum-integrated Be(n,2n) cross section at lower neutron energies. This work is summarized in the present report. The work is ongoing, and this document thus provides a status report rather than final numerical data