A Investigation of the Deuteron-Nucleus Tensor Interaction in ZIRCONIUM-90

An investigation of the role of the deuteron-nucleus tensor interaction is made through measurement of angular distributions of the cross section, analyzing powers and the polarization transfer observable (PTO) 3K_sp {y}{z^{'}z^ {'}} + K_sp {yy}{z^{'}z^ {'}} for deuteron elastic scattering from ^{90}Zr at 15 MeV. Two compact and efficient deuteron polarimeters based on the ^3He(d,p)^4He reaction were designed and built to perform the polarization transfer measurements. The observable K_sp{y} {z^{'}z^{' }} proved to be very sensitive to the presence of a T_{r}-type tensor interaction and also to provide information which cannot be obtained through measurement of tensor analyzing powers. The measurement of PTO and of the tensor analyzing power A_{xz} provide a particularly effective means of parameterizing the tensor interaction. Phenomenological optical model calculations give a real T_{r} potential which differs significantly from folding model predictions, in that it is weaker and predominantly surface-peaked. The imaginary T_{r} potential, however, is in qualitative agreement with the folding model. In addition to the optical model analysis, finite-range coupled -channels calculations were performed coupling the three most strongly populated ^{90}Zr (d,p)^{91}Zr states to the elastic channel in order to gauge the contribution of the (d,p) channel to the deuteron-nucleus tensor interaction. Coupling effects on the observables were found to be small and equivalent to that of an imaginary T_{r} tensor potential 1/5 of that used in the optical model analysis.