Measured Total Cross Sections of Slow Neutrons Scattered by Gaseous and Liquid $^{2}\mathrm{H}_{2}$

Measured Total Cross Sections of Slow Neutrons Scattered by Gaseous and Liquid ${}^{2}H_{2}$

F. Atchison, B. van den Brandt, T. Bryś, M. Daum, P. Fierlinger, P. Hautle, R. Henneck, K. Kirch, J. Kohlbrecher, G. Kühne, J. A. Konter, A. Pichlmaier, A. Wokaun, K. Bodek, M. Kasprzak, M. Kuźniak, P. Geltenbort, M. Giersch, J. Zmeskal, M. Hino, and M. Utsuro

Phys. Rev. Lett. 94, 212502 – Published 3 June 2005

Abstract

The total scattering cross sections for slow neutrons with energies $E$ in the range 300 neV to 3 meV for gaseous and liquid ortho- ${}^{2}H_{2}$ have been measured. The cross sections for ${}^{2}H_{2}$ gas are found to be in excellent agreement with both the Hamermesh and Schwinger and the Young and Koppel models. For liquid ${}^{2}H_{2}$ , we confirm the existing experimental data in the cold neutron range and the discrepancy with the gas models. We find a clear $1 / \sqrt{E^{'}}$ dependence at low energies for both states. A simple explanation for the liquid ${}^{2}H_{2}$ cross section is offered.