Proton Scattering from Polarized HELIUM-3 in the Energy Range from 20 TO 35 Mev.
The ('3)He analyzing powers have been measured at the forward angles ((LESSTHEQ) 100(DEGREES)) and at energies of 25, 30, 32.5, and 35 MeV. A polarized ('3)He target has been built using optical pumping with ('4)He -discharge lamps. An improved version of the equations describing the balance between polarizing and depolarizing processes was developed. Polarization through excitation of alternative transitions is discussed. Among the depolarizing processes, especially the reabsorption of pumping light is considered. The experience with the polarized target in nuclear scattering experiments is described. Single energy phase shift analyses have been made using the available precise data at seven energies between 19.5 and 35 MeV. Real phases up to L = 4, imaginary phases up to L = 3, and coupling between channels with J = 1 and 2 were allowed in the analysis. Singlet and triplet waves of the same angular momentum have considerable mixing, which reaches a maximum at 31 and 28 MeV for channels with respectively J('(pi)) = 1('-) and 2('+). Mixing angles for tensor coupling were always found to be close to zero. Several ambiguities in previous phase shift analyses are clarified. Also, the real phases have a smoother energy dependence than was found before. No significant excursions in the imaginary phases could be detected.
- Pub Date:
- Physics: Nuclear