A Effective Range Determination of Phase Shifts for the Elastic Proton HELIUM-3 Reaction Between the Energies of 0 and 12 Mev.

New measurements have been made of the observables from the {^3vec He(vec p, p)^3}He reaction in the energy range of 0 to 12 MeV. The new data were used in a global phase shift fit that utilized an energy dependent expansion of the phase shift parameters. The observable measurements were made possible through the construction of a new polarized ^3He target for use with the Wisconsin tandem accelerator. The design of the polarized ^3 He target consisted of a low pressure (2 Torr) double cell system which allowed the scattering cell to be cooled for increased target densities. The optical pumping medium was an infrared LNA laser that provided approximately 1 watt of power at the wavelength of 1.083 mu m. With this pumping source the achievable target polarizations were typically on the order of 30%. The target was designed to produce polarizations along the three lab axes of x, y and z. The scattering observables were measured with the Wisconsin crossed-beam polarized proton source and the new {^3vec H} e target. Measurements of the proton analyzing power (A_{y0}), ^3He analyzing power (A_{0y }) and spin correlation coefficient A _{yy} were performed for 10 angles at each of the five energies of 4.01, 5.54, 7.03, 8.52 and 10.01 MeV. Measurements were also made of the spin correlation coefficients A_{xx}, A_{zz}, A_{xz }, and A_{zx} at 5.54 MeV. In order to reproduce the measurements, a new procedure were developed to express the scattering observables as functions of the phase shifts. The parameterization of the phase shifts was accomplished using a modified effective range expansion for each parameter. This was incorporated into a computer search routine that performed a global fit on the new measurements plus over 900 existing ^3He(p,p)^3He observables. The addition of the new spin correlation measurements into the data base has made it possible to uniquely specify the low energy phase shifts. The final fit has a reduced chi_sp{nu}{2 } per degree of freedom of 0.959, and a confidence level of 0.823. The new data data also allowed the specification of global phase shift uncertainties that represent a significant improvement in the results of past analyses.