International Conference on Nuclear Data for Science and Technology 2007
DOI: 10.1051/ndata:07435

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

P. Mermod¹, J. Blomgren¹, C. Johansson¹, A. Öhrn¹, M. Österlund¹, S. Pomp¹, B. Bergenwall², J. Klug¹, L. Nilsson¹, N. Olsson³, U. Tippawan⁴, P. Nadel-Turonski⁵, O. Jonsson⁶, A. Prokofiev⁶, P.-U. Renberg⁶, Y. Maeda⁷, H. Sakai⁷, A. Tamii⁷, K. Amos⁸ and R. Crespo<sup>9

1</sup>  Department of Neutron Research, Uppsala University, P.O. Box 525, 75120 Uppsala, Sweden
²  Department of Nuclear and Particle physics, Uppsala University, Sweden
³  Swedish Defence Research Agency, Stockholm, Sweden
⁴  Fast Neutron Research Facility, Chiang Mai University, Thailand
⁵  The George Washington University, Washington, DC, USA
⁶  The Svedberg Laboratory, Uppsala University, Sweden
⁷  Department of Physics, University of Tokyo, Japan
⁸  School of Physics, University of Melbourne, Australia
⁹  Departamento de Fisica, Instituto Superior Técnico, Lisboa, Portugal

jan.blomgren@tsl.uu.se

Published online: 21 May 2008

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 ¹²C(n,n) elastic scattering data have been measured for normalization purposes, and ¹⁶O(n,n) data have been obtained for the first time at this energy. It was possible to extract ¹²C(n,n') and ¹⁶O(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.

© CEA 2008