Search results for "polarization."

Measurement of proton and nitrogen polarization in ammonia and a test of equal spin temperature

1998

The 1996 data taking of the SMC experiment used polarized protons to measure the spin-dependent structure function g(1) of the proton. Three liters of solid granular ammonia were irradiated at the Bonn electron linac in order to create the paramagnetic radicals which are needed for polarizing the protons. Proton polarizations of +/- (90 +/- 2.5)% were routinely reached. An analysis based on a theoretical line shape for spin-1. systems with large quadrupolar broadening was developed which allowed the nitrogen polarization in the ammonia to be determined with a 10% relative error. The measured quadrupolar coupling constant of N-14 agrees well with earlier extrapolated values. The polarization…

Spin Polarization of Electrons by Resonance Scattering from Mercury

1980

Hg- compound ion states formed by electron impact with neutral mercury atoms at collision energies of 4.55, 4.71, 4.94, and 5.51 eV show up in the 2S1/2, 2D3/2, 2D5/2, and 2D5/2 scattering states in order of increasing energy. This identification is supported by the observed energy dependence of (i) elastic (e-, Hg) differential cross section, of (ii) 63P0 excitation of mercury by electron impact, and of (iii) spin polarization of electrons scattered elastically from mercury.

NMR Hyperpolarization of Established PET Tracers

2018

Measurement of GEp/GMp via polarization transfer at Q2 = 0.4 GeV /c2

2001

The polarization transfer from longitudinally polarized electrons to protons in the elastic scattering p( e, e' p) has been measured around Q2 = 0.4 (GeV/c)2 with the three-spectrometer facility at the Mainz microtron MAMI. From this polarization transfer the ratio G Ep/(G Mp/μp) has been determined. The ratio is found to be slightly less than unity in agreement with recent results from other laboratories and from the Rosenbluth separation of cross-sections measured with unpolarized electrons.

New model and code for calculation of product yields in fusion-fission reactions

2003

A new version of the theoretical model and computing code for calculations of the pre- and post-scission light particle spectra and multiplicity distributions, the evaporation residue cross sections, and the fission product yield cross sections has been developed. The most important dynamical effects (nuclear friction and light particle emission at the descent from saddle to scission point) in the decay of heated rotating compound nuclei were included in consideration [1]. The fission characteristics have been calculated for every compound nucleus at excitation energy and angular momentum at the scission point. The contributions from different fission modes including the superasymmetric one…

Polarization Observables in Deuteron Electrodisintegration

1992

The electrodisintegration of the deuteron with polarized beam and target is investigated. The additional polarization form factors (inclusive reaction) and structure functions (exclusive reaction) are discussed. The sensitivity of these form factors and structure functions to the potential model, to meson and isobar degrees of freedom, and to electromagnetic form factors is studied in different kinematical regions.

What can be learnt about nuclear polarization from a consistency analysis ofe ? cross sections and muonic X-rays for208Pb and the isotone pair209Bi/2…

1977

A joint analysis of recent electron scattering cross sections and muonic atom X-ray energies is performed for208Pb and the isotone pair209Bi/208Pb. From the compatibility of the experimental data one can learn about the nuclear polarisation correction. However, we find this information not to be as accurate as other authors claimed when we take into consideration the ambiguities in the treatment of the corrections of the higher levels.

Contributions to the electromagnetic form factors of the deuteron from isobar configurations

1974

A nonrelativistic calculation of the elastic electron deuteron scattering has been performed in which the effects arising from nucleon polarization have been systematically investigated. These effects have been taken into account by admixing isobar configurations into the deuteron wave function. Explicit expressions for the various contributions to the respective deuteron form factors have been given. At higher momentum transfers inclusion of the isobar configurations leads to a substantial increase in the form factors which qualitatively appears to account for at least some of the discrepancies between theory and experiment.

Branching fraction measurements of the color-suppressed decaysB¯0toD(*)0π0,D(*)0η,D(*)0ω, andD(*)0η′and measurement of the polarization in the decayB…

2011

We report updated branching fraction measurements of the color-suppressed decays B ^(0) → D^(0)π^(0), D^(*0)π^(0), D^(0)η, D^(*0)η, D^(0)ω, D^(*0)ω, D^(0)η′, and D^(*0)η′. We measure the branching fractions (×10^(-4)): B(B^0 → D^(0)π^(0)) = 2.69±0.09±0.13, B(B^(0) → D^(*0)π^(0)) = 3.05±0.14±0.28, B(B^(0) → D^(0)η) = 2.53±0.09±0.11, B(B^(0) → D^(*0)η) = 2.69±0.14±0.23, B(B^(0) → D^(0)ω) = 2.57±0.11±0.14, B(B^(0) → D^(*0)ω) = 4.55±0.24±0.39, B(B^(0)→D^(0)η′) = 1.48±0.13±0.07, and B(B^(0) → D^(*0)n′) = 1.49±0.22±0.15. We also present the first measurement of the longitudinal polarization fraction of the decay channel D*0ω, fL=(66.5±4.7±1.5)%. In the above, the first uncertainty is statistical …

A spin rotator for producing a longitudinally polarized electron beam with MAMI

1993

Abstract The design and performance characteristics of a full 4 π-space spin rotator for 100 keV electrons are described. The spin rotator was developed as part of the acceleration scheme for polarized electrons in the MAINZ race track microtron cascade MAMI [1]. It allows to orientate the polarization vector in any direction before injection. Thus it is possible to optimize the longitudinal polarization component, required for experiments with polarized high energy electrons, at target position. With this scheme various experimental halls can be supplied with longitudinally polarized electrons in the full energy range of MAMI between 180 and 855 MeV.