High-Intensity Deuteron Linear Accelerator (FMIT)

For fusion reactors to become operational, one of the many problems to be solved is to find materials able to withstand the intense bombardment of 14-MeV neutrons released by the fusion process. The development of alloys less likely to become damaged by this neutron bombardment will require years of work, making it desirable to begin studies in parallel with other aspects of fusion power generators. The Fusion Materials Irradiation Test (FMIT) Facility, to be built at the Hanford Engineering Development Laboratory (HEDL), Richland, Washington, will provide a high neutron flux and a neutron energy spectrum representative of fusion reactor conditions in volumes adequate to screen and qualify samples of candidate fusion reactor materials. FMIT´s design goal is to provide an irradiation test volume of 10 cm3 at a neutron flux of 1015 n/cm2-s, and 500 cm3 at a flux of 1014 n/cm2-s. This will not allow testing of actual components, but samples in the most intense flux region can be subjected to accelerated life testing, accumulating in one year the total number of neutrons seen by a fusion reactor in 10-20 years of operation. To produce the neutrons, a 100-mA, 35-MeV deuteron beam will be directed onto a 2-cm-thick, 600-gpm curtain of liquid lithium metal, which strips the deuterons and allows the remaining neutrons to continue on to the test samples. The deuterons will be produced by the largest component of the facility, a high-intensity, continuously operating linear accelerator (Linac).