Polarization of neutrons from proton break-up of deuterium

Abstract

Measurements of the neutron polarization in the p-d breakup reaction are reported. The polarization of breakup neutrons from D(p,n[arrow]) has been measured at E[subscript p] = 21.4 MeV, ??[subscript lab] = 18??, as a function of neutron energy with an accuracy of approximately ?? 0.01 using a four parameter technique. The measurement is consistent with zero from 8 to 13 MeV, but shows a small but significant positive polarization from 14 to 18 MeV. A similar measurement of the breakup neutrons from the H(d,n[arrow])2p reaction at the same center-of-mass momentum (E[subscript d] = 42.8 MeV), also at ??[subscript lab] = 18?? shows non-zero polarization over the neutron energy region 8 to 25 MeV and peaks to about -0.05 ?? 0.01. In both cases, the polarization of the breakup neutrons is opposite in sign to that expected if the dominant process is simple quasi-free scattering.