Measurements of the $\mathrm{pp}$ spin correlation coefficients $A_{\mathrm{xx}},$ $A_{\mathrm{yy}},$ and $A_{\mathrm{xz}}$ and analyzing power $A_y$ for $\mathrm{pp}$ elastic scattering at 197.8 MeV over the angular range $4.5°$–$17.5°$ have been carried out. The statistical accuracy is approximately $\pm 0.01$ for $A_{\mathrm{mn}}$ and $\pm 0.004$ for $A_y,$ while the corresponding scale factor uncertainties are 2.4% and 1.3%, respectively. The experiment makes use of a polarized hydrogen gas target internal to a proton storage ring (IUCF Cooler) and a circulating beam of polarized protons. The target polarization $\mathrm{}(Q=0.79\mathrm{})\mathrm{}$ is switched in sign and in direction $\mathrm{}(x,y,z)\mathrm{}$ every 2 s by reversing a weak guide field (about 0.3 mT). The forward-scattered protons are detected in two sets of wire chambers and a scintillator, while recoil protons are detected in coincidence with the forward protons by silicon strip detectors placed 5 cm from the proton beam. The background rate from scattering by the walls of the target cell is $(0.2\mathrm{}\pm 0.2)$% of the good event rate. Analysis methods and comparisons with $\mathrm{pp}$ potential models and $\mathrm{pp}$ partial wave analyses are described.

• Received 17 September 1996

DOI:https://doi.org/10.1103/PhysRevC.55.597