Fast and Thermal Neutron Sources
High flux neutron sources are needed for a broad range of materials research and for radioisotope production. New reactors, especially fast spectrum research reactors, are unlikely to be built and licensed in the US for at least the next decade. Particle accelerator driven neutron sources offer an alternative, and can generate average thermal or fast neutron fluxes of ~1014 neutrons/cm2∙s without uranium, which is comparable to flux available in nuclear reactors. With a small quantity of low-enriched uranium (LEU), these accelerator driven sources can generate average thermal or fast fluxes of ~1016 neutrons/cm2∙s. By pulsing the accelerator, the peak flux can be more than one hundred times higher than the average flux. These accelerator driven neutron sources are licensed as an accelerator and target, not a reactor, which greatly simplifies and expedites the licensing process.
Niowave offers a compact and inexpensive superconducting electron linac to produce high intensity fast or thermal neutron fluxes. The electron beam impinges on a high-Z liquid metal target to generate x-rays and then neutrons via (γ, n) reactions. The neutron spectrum can be tailored for fast or thermal spectra depending on the reflectors and moderators used.
As an example, our 40 MeV, 100 kW continuous wave (CW) superconducting linac can produce a fast neutron flux up to 1014 neutrons/cm2∙s using a liquid lead target without uranium for testing of Generation IV materials. An example distribution of the neutron flux is shown below in Figure 1.
Figure 1. Neutron flux generated within a 3 x 3 cm high-Z target. A 40 MeV, 100 kW electron beam is incident from the left. A large region (~1 cm in radius and ~2.5 cm long) with neutron flux over 1013 neutrons/cm2 per second exists, more than sufficient for testing novel Generation IV materials