Three years of cross-section measurements of (n,xn) threshold reactions at TSL Uppsala and NPI Řež

Abstract

We use (n,xn) threshold reactions in various materials to measure high energy neutron flux from spallation reactions. Unfortunately, no experimental cross-section data exist for reactions with x higher than four and neutron energies over ∼ 40 MeV. With the support from EFNUDAT we performed seven successful (n,xn) cross-section measurements in two campaigns exploiting the quasi-monoenergetic neutron source at The Svedberg Laboratory in Uppsala, Sweden. Neutron energies from the 7Li(p, n)7Be based source were in the region 22 to 94 MeV. We carried out additional four irradiations with neutron energies from 17 up to 34 MeV using the quasi-monoenergetic neutron source of the Nuclear Physics Institute in Řež. We studied Al, Au, Bi, I, In, and Ta materials. Although we used different neutron sources, gamma detectors and foil geometries, we obtained consistent results. We observed good agreement with the data in EXFOR, so we believe we have understood and solved all possible sources of uncertainties.