95 MeV neutron scattering on hydrogen, deuterium, carbon and oxygen

Abstract

Abstract. Three neutron-deuteron scattering experiments at 95 MeV have been performed recently at The Svedberg Laboratory in Uppsala. Subsets of the results of these experiments have been reported in two short articles, showing clear evidence for three-nucleon force effects. In this paper, we present further discussion of the results. We obtained excellent precision in the angular range of the nd cross section minimum. The data are in good agreement with Faddeev calculations using modern NN potentials and including 3N forces from a 2π-exchange model, while the calculations without 3N forces fail to describe the data. CHPT calculations at next-to-next-to-leading order represent an improvement compared to calculations with NN forces only, but still underestimate the data in the minimum region. In addition to neutron-deuteron scattering data, neutron-proton and 12 C(n,n) elastic scattering data have been measured for normalization purposes, and 16 O(n,n) data have been obtained for the first time at this energy. It was possible to extract 12 C(n,n') and 16 O(n,n') inelastic scattering cross sections to excited states below 12 MeV excitation energy. These data are shown to have a significant impact on the determination of nuclear recoil kerma coefficients.

Fast Neutron Scattering on Carbon and Oxygen

“…These new carbon and oxygen data were reported together with the np and nd data in Ref. [11]. In this publication, we pointed out that the carbon and oxygen data might be relevant for cancer treatment of tumors with fast neutrons, and we identified angular regions where the accuracy of the theoretical calculations were not satisfying.…”

“…The left panels of the figure correspond to elastic neutron scattering on carbon (here, at 95 MeV), and the right panels correspond to elastic neutron scattering on oxygen. The data are from Mermod et al [11], Klug et al [12], Salmon [13] and Osborne et al [14]. The theoretical curves are predictions from the Koning and Delaroche global potential [15], the Watson global potential [16], Amos et al [17], and Crespo et al [18] (see Refs.…”

“…The primary aim of the experiments was to investigate three-body force effects in elastic neutron-deuteron (nd) scattering. The nd data were first published in a short communication [10], and a detailed article has been submitted recently [11]. For normalization purposes, differential cross sections for np scattering and 12 C(n,n) scattering were also measured, using a water and a graphite target, respectively.…”

An upgrade of the SCANDAL setup for measurements of elastic neutron scattering at 175 MeV

“…(Öhrn et al, 2008) or (Mermod et al, 2006). The work has now started to complete a similar series of measurements at 175 MeV.…”

Light-Ion Production and Fission Studies Using the Medley Facility at TSL

“…Recently, we have started a program on measuring angular distributions of fission fragments [5]. The facility has also proven to be a valuable tool in the search for three-body force effects [6][7]. All these measurements have been performed at the "old" neutron beam at TSL [8].…”