Preparation and characterization of the LiF target for monoenergetic neutron generation

Monoenergetic neutron radiation fields based on the 7 Li(p,n) 7 Be reaction require thin, uniform, and chemically stable lithium targets capable of sustained operation under proton beam irradiation. In this study, lithium fluoride (LiF) targets were designed, prepared, characterized, and tested in proton beam experiments. The target thickness was optimized by trading off neutron fluence and energy spread. The LiF layers were deposited onto silver backings by resistive thermal evaporation under high vacuum. The thickness measured on co-deposited silicon substrates was 455 ± 3 nm, while gravimetric analysis gave an areal density of 98.24 μg∙cm −2 . Characterization of the target’s physicochemical properties indicated good uniformity and stoichiometry consistency. During the 8 h beam test, the target operated stably, yielding a neutron fluence of 225.8 cm −2 ∙μC -1 at 0° and 100 cm distance, which agrees with simulations within 10%. The prepared LiF target meets the basic requirements for establishing monoenergetic neutron radiation fields.