Investigation of aerogel, saturated foam, and foil for thermal neutron detection

A recent shortage in ³He for neutron detection has caused an increase in research efforts for a viable replacement. Three materials, borosilicate aerogel, ⁶LiF saturated foam, and natural lithium foil, have been investigated as neutron detection materials. The materials of focus are designed in such a way that allow both reaction products from the ⁶Li(n,α)³H and ¹⁰B(n,α)⁷Li interactions to escape the absorber and enter a detector volume simultaneously. This attribute dramatically increases the neutron detection efficiency of the detector. The neutron response pulse-height spectra of borosilicate aerogel, 4.5 percent saturated ⁶LiF foam, and 10 layers of 30, 50, and 75 μm thick Li foil are presented. The theoretical neutron detection efficiencies of saturated foam and Li foils of different thicknesses are presented and compared to experimentally obtained values.