Remarks concerning the efficiency of a booster neutron source

Abstract In the present paper criteria are defined for the comparison of the efficiency of a multiplying booster target with a non-multiplying accelerator target for different injection times and pulse widths. It is shown that for solid state physics scattering experiments using impinging neutrons in the energy range of 0.05⩽ E ⩽10 eV, there exists a lower limit of 1 μs for the pulse width and therefore a booster target with an amplification of A = 10, a generation time τ = 0.02 μs, has a “figure of merit”: FM= 10 and for “symmetric pulses” an “effective figure of merit”: EFM = 7.5. For the epi-thermal energy region, an optimum slowing down flux is achieved for an effective water moderator thickness of 28 mm resulting in an energy dependent moderator pulse width: Δt ≅ 2 E (μ s , E in eV ) . If the booster pulse is matched to the moderator responsi function, then the accelerator injection time t 0 ≅ 1 2 Δt . This leads to an energy dependent figure of merit: FM(E), that is rapidly decreasing with energy and equal to 1 at 50 eV.