3H(p, n) 3He reaction with polarized protons from threshold to 2.9 MeV

Abstract

A polarized beam was used to measure angular distributions of the analyzing power of the 3H( p , n) 3He reaction at 9 energies from 1.30 to 2.90 MeV. The data were measured typically to an accuracy of 0.02 with a target 25 keV thick at 2 MeV bombarding energy. The analyzing power can be fitted with associated Legendre polynomials. The coefficient of P 1 1 is small, near zero at the upper and lower energies and negative in between; the coefficient of P 2 1 is much larger and positive, rising to a maximum at 2.2 MeV. Comparison of the analyzing power A with earlier data for the neutron polarization P induced with unpolarized protons shows the coefficients of P 1 1 to be equal and those of P 2 1 to have a similar energy dependence but with larger values for A than for P. Theoretical treatment elsewhere of the inequality of P and A infers that transitions between 3P 2 and 3F 2 are responsible. Polarization contour maps are given.