Abstract
The Wolfenstein (or triple scattering) parameter and the polarization in neutron proton scattering has been measured in the "intermediate" energy region at the TRIUMF cyclotron in Canada. A polarised neutron beam was produced by the scattering of polarised protons off liquid deuterium, and the scattering of this beam from liquid hydrogen was observed. The polarization of the final state proton was analysed by a carbon polarimeter with wire chambers to reconstruct the tracks. The asymmetry has been extracted from the polarimeter data by two independent methods, and we show these to be in complete agreement. Complete results from one of these methods is presented here. A phase shift analysis has been performed with the enlarged data base, and stable solutions are found when the I=0 G waves are set to theoretical values: we compare the I=0 phase shifts as a function of energy with the potential model predictions of Vinh Mau et al (ref VI 73) and show some disagreement, notably in the D-waves.