Neutron capture of UO2 targets prepared by spin-coating assisted combustion synthesis

Two uranium dioxide (UO2) targets of (414 +/- 23) nm and (1092 +/- 93) nm thicknesses were prepared on 6061 aluminum alloy and puratronic grade aluminum backing materials. The targets were deposited with a novel method combining spin coating and solution combustion synthesis (SCS). The target layers consisted of small (3-7 nm) UO2 grains and uniformly distributed ultra-small (1-3 nm) pores. The prepared targets were tested at the Los Alamos National Laboratory's LANSCE facility for neutron irradiation damage and suitability for neutron capture experiments. The samples showed no signs of target material loss after the irradiation. However, irradiation caused a significant increase in the grain size (4-10 nm), as well as upward mass diffusion and coalescence of the pores due to the thermal spikes. The magnesium in the aluminum 6061 alloy backing also diffused into the UO2 layer during neutron irradiation. The structural changes in the target after the irradiation do not affect the data from neutron capture. The new method can be used more broadly to prepare other actinide targets for nuclear physics experiments.