The elastic scattering of protons by He_
Clegg, Thomas Boykin
Barnard, A. C. L.
Master of Arts
The Bonner Nuclear Laboratories tandem Van de Graaff has been used to extend the He3(p,p)He3 elastic scattering measurements of Tombrello et ai.) from 14.5 to 11.5 MeV. The small volume gas scattering chamber built by Jones) was sealed off from the accelerator vacuum system with SiO or Ni entrance foils and equipped with solid state detectors. and a scintillation counter for the experiment. Three excitation functions at center-of-mass angles of 900, 125° 18t, and 161° 12' have been measured from 4.5 to 10.4 MeV in steps of 200 keV. No sharp structure was observed. Angular distributions were measured at 22 angles between 27° 38t and 166° 35, in the center-of-mass system at bombarding energies of 4.55, 5.51, 6.52, 7.51, 8.51, 9.51, 10.38, and 11.48 MeV. A phase shift analysis has been made of these data using one phase shift for each of the values of 4 through 12=2. The p -wave parameter was found to be increasing positively in qualitative agreement with the results of Tombrello et. al. Cross sections calculated from the phase shifts show large deviations from the experimental values in the region around 100° in the center-of-mass system. This indicates that some spin-dependent splitting of the phase shifts must be required to fit the data.