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We describe the upgraded time-of-flight facility at the Indiana University Cyclotron which has been used to measure the polarization transfer induced in ( p → , n → ) reactions at intermediate energies, Ep=100–200 MeV. The Indiana Neutron POLarimeter (INPOL) is able to measure simultaneously two orthogonal neutron spin polarizations induced in charge exchange reactions with polarized proton beams oriented in each of the three spin states, normal ( N → ), sideways ( S → ) and longitudinal ( L → ).

Gamow-Teller transition strengths obtained in the {sup 127}I(p,n){sup 127}Xe reaction studied at 94, 159, and 197 MeV incident proton energies are presented, and used to evaluate the efficiency of {sup 127}I as a solar neutrino detector. Excitation of the J{sup {pi}}=(3/2){sup +} first excited state at E{sub x}=0.125 MeV in {sup 127}Xe, sensitive to {sup 7}Be solar neutrinos, is evaluated. The sum of Gamow-Teller strength up to particle emission threshold and up to 20 MeV excitation energy are also reported. This paper also provides a new measurement of the Coulomb displacement energy {Delta}E{sub c}, the excitation energy of the isobaric analog state, and the centroid of the Gamow-Teller resonance in {sup 127}Xe. {copyright} {ital 1999} {ital The American Physical Society}

A complete set of spin observables was measured for the 2 H(p,n)2p reaction at 200 MeV at the Indiana University Cyclotron Facility (IUCF) with the high intensity polarized ion source (HIPIOS) and the Indiana Neutron Polarization Facility (INPOL). The incident proton beam was delivered successively in each of the three spin states, normal ( N ), sideways ( S ), and longitudinal ( L ). Two large-volume neutron polarimeters placed along the 0° and 24° beam lines measured the polarizations of the emitted neutrons in each of the three spin states. The measured cross sections and spin observables are compared with three-body Faddeev calculations, which generally agree with the data. The ratio of the longitudinal to transverse response is suppressed rather than enhanced, as predicted by some models.

The spin asymmetries in the momentum distributions of the neutron and proton in He-3 are obtained from a Faddeev calculation of the ground state. Both two- and three-body configurations are found to be important. Using a PWIA model and measurements of the spin asymmetries in (3)((p) over right arrow,2p) and (3)((p) over right arrow,pn) quasielastic scattering at 197 MeV the asymmetries in the momentum distributions are experimentally determined. Good agreement between theory and experiment is found up to initial nucleon momenta of 300 MeV/c.

We report measurements of spin correlations and analyzing powers in $^{3}\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}(\stackrel{\ensuremath{\rightarrow}}{p}, 2p)$ and $^{3}\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}(\stackrel{\ensuremath{\rightarrow}}{p}, pn)$ quasielastic scattering as a function of momentum transfer and missing momentum at 197 MeV using a polarized internal target at the Indiana University Cyclotron Facility Cooler Ring. At sufficiently high momentum transfer we find $^{3}\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}(\stackrel{\ensuremath{\rightarrow}}{p}, pn)$ spin observables are in good agreement with free $p\ensuremath{-}n$ scattering observables, and therefore that $^{3}\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}$ can serve as a good polarized neutron target. The extracted polarizations of nucleons in $^{3}\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}$ at low missing momentum are consistent with Faddeev calculations.

We describe the first experiment to use a polarized internal gas target and polarized beam in a storage ring. A laser optically pumped polarized He internal gas target has been used with circulating beams of 197-414 MeV polarized protons to carry out an extensive set of measurements of spin dependent scattering. A large acceptance non-magnetic detector system consisting of wie-chambers, scintillators and microstrip detectors was used to detect protons, neutrons, deuterons, and He-3 nuclei from the beam-target interaction. It is demonstrated that these techniques result in low backgrounds (< 1%) due to scattering from species other than the polarized target gas and allow detection of low energy recoiling nuclei. Specific issues such as interfacing the experiment to the storage ring and monitoring the luminosity and polarizations are discussed in detail.

In this paper, we present a complete set of polarization-transfer observables measured at 197 MeV in the quasifree region for $(\stackrel{\ensuremath{\rightarrow}}{p},\stackrel{\ensuremath{\rightarrow}}{n})$ reactions on ${}^{2}\mathrm{H}$ and ${}^{3,4}\mathrm{He}$ targets. Data were obtained at laboratory scattering angles of $13\ifmmode^\circ\else\textdegree\fi{},$ $24\ifmmode^\circ\else\textdegree\fi{},$ $37\ifmmode^\circ\else\textdegree\fi{},$ and $48\ifmmode^\circ\else\textdegree\fi{}$ for the ${}^{2}\mathrm{H}$ target and at $13\ifmmode^\circ\else\textdegree\fi{}$ and $37\ifmmode^\circ\else\textdegree\fi{}$ for the ${}^{3,4}\mathrm{He}$ targets. The data span an energy-loss range up to 150 MeV, with a corresponding momentum-transfer range $q=0.75--2.4 {\mathrm{fm}}^{\ensuremath{-}1}.$ The polarization-transfer observables are used to calculate the center-of-mass polarization observables. The empirical results for the ${}^{2}\mathrm{H}$ target are compared to the observables obtained from the free nucleon-nucleon database and with Faddeev-type calculations. No discernible differences are observed in either the values of polarization-transfer observables or in the center-of-mass polarization observables among the three nuclei studied in this paper.

C. Hautala, J. Rapaport, M. Palarczyk, D. L. Prout, D. A. Cooper, G. Savopulos, B. Anderson, A. Baldwin, C. C. Foster, C. D. Goodman, K. Hicks, R. Howes, M. S. Islam, B. A. Luther, D. M. Manley, R. Madey, E. Sugarbaker, T. N. Taddeucci, I. Van Heerden,* J. Watson, X. Yang, and W. -M. Zhang Ohio University, Athens, Ohio 45701 Henryk Niewodniczanski Institute of Nuclear Physics, 31-342 Krakow, Poland Indiana University Cyclotron Facility, Bloomington, Indiana 47405 Department of Physics, Kent State University, Kent, Ohio 44242 The Ohio State University, Columbus, Ohio 43210 Ball State University, Muncie, Indiana 47306 Concordia College, Moorhead, Minnesota 56562 Los Alamos National Laboratory, Los Alamos, New Mexico 87545 ~Received 31 July 2001; published 19 February 2002!

Measurements of analyzing powers and spin correlation parameters for 3He(p↘,2p) and 3H↘e(p↘,pn) quasielastic scattering have been carried out using a polarized internal 3He target and a stored, polarized proton beam. They were made over a wide kinematic range with a proton energy of 197 MeV and a large acceptance detector system which allowed the simultaneous measurement of both reactions. At momentum transfers sufficiently high to minimize rescattering effects, the (p,pn) results are in agreement with PWIA calculations. The (p,2p) results were found to be less sensitive to kinematic conditions and are also in agreement with calculations.