Abstract
Differential cross sections have been obtained for the elastic scattering of neutrons by tritium and by at Mev over the angular range 27° to 161° in the c.m. system. The Los Alamos large Van de Graaff accelerator and pulsed-beam time-of-flight facility were employed, and the scattering samples were contained in small thin-walled stainless steel spheres. One-third mole of was contained at 5000 psi and one-half mole of tritium was prepared in the form of Ca. Absolute cross sections were determined from a comparison with the scattering from a thin shell of C at each energy, together with calibration of the relative sensitivity of the detector as a function of energy by the known forward yield of the reaction. The angular distributions for -T scattering are in excellent agreement with the calculations of Bransden, Robertson, and Swan based on a Serber exchange force. The - measurements favor qualitatively the Serber rather than the symmetrical exchange force used in the calculations, but the agreement is poorer than that obtained for -T scattering. The polarization of elastically scattered 1-Mev neutrons was found to be less than 5% for both samples, unlike the strong polarization observed in - scattering.
- Received 9 May 1960
DOI:https://doi.org/10.1103/PhysRev.119.1981
©1960 American Physical Society