PRODUCTION OF POLARIZED N-12 WITH THE C-12(P,N-12)N0 REACTION

The polarization transferred to N-12 in the C-12(p -->, N-12 -->)n0 reaction has been measured at E(p) = 50 and 72 MeV. In agreement with previous work, the N-12 polarization was a strong function of the material in which the ions stop, implying a complex depolarization mechanism. The largest nuclear polarization observed, P0 = 0.260 +/- 0.002, was for N-12 implanted in Al. This result gives the lower bound K(y)y' greater-than-or-equal-to 0.377 +/- 0.003 for the transverse polarization-transfer coefficient. Distorted-wave calculations predict K(y)y' should be approximately 2/3. The angular distribution of K(y)y' at E(p) = 72 MeV is nearly isotropic, in agreement with the distorted-wave prediction. The electronic polarization relaxation time T1 for N-12 implanted in C, Al, Ni and Au was found to be approximately constant and much longer than the N-12 half-life; viz., T1 = 0.150 +/- 0.014 s.