G.C. Salzman

Techniques for polarization transfer coefficient determination

Abstract It is shown how polarization transfer coefficients in reactions with the spin structures 1 2 + A → 1 + B , 1 + A → 1 + B and 1 + A → 1 2 + B can be determined by ratio techniques in which detector efficiencies, solid angles, and relative counting interval are cancelled out. The relative merits of using a “polarized-to-unpolarized” ratio method to “spin-up-to-spin-down” ratio method are discussed.

Polarization and polarization transfer in the 2H(d, n)3He reaction at 10 MeV

Abstract Angular distributions of six polarization transfer coefficients K x x′ (θ), k x z′ (θ), K z x (θ), K z z (θ), and K yy y (θ) ; of the four analyzing powers Ay(θ), Axx(θ), Ayy(θ), and Azz(θ); and of the polarization function Pý(θ), have been measured atEd = 10.00 MeV for the reaction 2H(d, n)3He. Measurements were made for neutron lab angles between 0° and 80° in 10° steps. Additionally the y-axis associated quantities were measured at θ1ab = 99°. Most of the measured coefficients are large at some angles and all show considerable variation with angle.

A surface-delta description of analyzing power measurements for collective states of Ni and Zn isotopes☆

Abstract Analyzing powers and differential cross sections for the inelastic scattering of 15 MeV polarized protons to the stronger collective states of 58, 60 Ni and 64 Zn have been measured. The data were compared to detailed microscopic reaction calculations using a central plus spin-dependent effective interaction. The nuclear structure wave functions used were obtained from a quasiparticle random-phase appoximation calculation using a spin-dependent surface delta interaction and a basis set containing both neutron and proton configurations. The overall quality of the fits strongly suggests that the surface-delta wave functions provide a good representation for spherical nuclei in this intermediate mass range. The effects of exchange and further modifications to the microscopic effective interaction are discussed.

Longitudinal polarization transfer in the D(d,n)3He reaction at 0°

Abstract We have measured the longitudinal neutron polarization in the D( d , n ) 3 He reaction, at θ=0°, for an incident longitudinally polarized deuteron beam. A deuteron energy range of 3.3–14.9 MeV was covered. The polarization transfer from the deuteron to the neutron is found to be large, and the reaction is potentially useful as a source of polarized neutrons.

VECTOR TO TENSOR POLARIZATION TRANSFER IN PROTON--DEUTERON ELASTIC SCATTERING.

Publisher Summary This chapter discusses an experiment to study the paper measurements of the second-rank polarization of the deuterons that recoil from proton–deuteron elastic scattering in cases where the incident protons were polarized. The polarization of the recoil deuterons was described in laboratory helicity frame to form a right-handed coordinate system. Ratios between the counts observed in each detector with a polarized beam to the counts observed with an unpolarized beam were obtained. The unpolarized beam was typically ∼ 20 times more intense than the available polarized beam. The results were consistent with zero, in view of the errors, but the effects of the order of ∼ 0.05 cannot be ruled out.

Longitudinal polarization transfer in the T→p, →n)3He reaction☆

Abstract The longitudinal polarization of neutrons has been measured for the reaction T →p , →n ) 3 He with the incident proton beam longitudinally polarized. Measurements were performed at 0° for proton energies from 4 to 15 MeV and an angular distribution was measured at 10 MeV. The data determine the polarization transfer coefficient Kzz′, which is equivalent to the Wolfenstein A′ parameter for nucleon-nucleon scattering. The quantity Kzz′ at 0° increases from about 0.3 at 3 MeV incident energy to 0.9 at 9 MeV, and then decreases to 0.5 at 15 MeV. The data are computed with R-matrix calculations which reproduce the qualitative shape of the data at 0° and the angular distribution at 10 MeV.

PRELIMINARY MEASUREMENTS OF POLARIZATION TRANSFER IN 4He(→d,→d)4He ELASTIC SCATTERING

Publisher Summary This chapter provides an overview on polarization transfer measurements for deuteron-4He elastic scattering. These measurements are sufficiently complete to allow an unambiguous determination of the scattering matrix at the chosen energies and angles. This information can be used to make certain that a given set of energy-dependent phase shifts is on the correct branch. This helps in assigning positions, quantum numbers, and widths to the various states in 6Li. An approximate knowledge of the phase shifts, but with assurance that one is on the right branch, should help in the determination of whether the required condition is met. If it is met, a valuable calibration standard for deuteron tensor polarization will be obtained. The data presented in the chapter was taken at a laboratory deuteron angle 30o. Eleven polarization transfer coefficients were measured for 4.8, 6.3, and 7.7 MeV while six were measured for 8.6 MeV. This constitutes the determination of the matrix; in principle, only three properly selected coefficients, together with the analyzing tensors and the cross section, are required. The chapter also highlights the experimental technique and delineates graph plots of the polarization transfer coefficients for d-α elastic scattering at a laboratory angle of 30°.