(67) and appendix A.) Abragam (ref. 28) shows that the second moment M2 of a reso- ...... Boucher, Jean-Paul; and Nechtschein, Maxime: Modele du Rseau de ...
NASA Website
... Abstract : A detailed comparison is made of the relative advantages of the Overhauser effect and the Abragam effect for obtaining stimulated ...
DTIC Science & Technology
The dynamic polarization of F/sup 19/ was studied in polytetrafluoroethylene irradiated with 1-Mev electrons. Its value was determined for different concentrations of paramagnetic centers as a function of the exterior magnetic field and of the intensity of the polarizing microwave field. The saturation of the normal paramagnetic resonance was also determined. If the ...
Energy Citations Database
The nuclear relaxation of very dilute 111Cd impurities in liquid Se, Te, and Se-Te alloys has been investigated by measuring the time-dependent perturbation of the angular correlation between ? rays emitted during the decay of 111In to 111Cd. The relaxation is always within the Abragam-Pound motionally narrowed limit and is found to be a function of the density of paramagnetic ...
NASA Astrophysics Data System (ADS)
An overview of the research performed in Saclay using lithium products is given starting with the pioneering work of Abragam's group and ending with the shut down of the local accelerators. From the very beginning, lithium compounds have been linked to the development of polarized targets. In 1960, Abragam used 6LiF to validate the Overhauser effect in ...
Nuclear magnetic resonance (NMR) is a powerful tool for elucidating protein dynamics because of the possibility to interpret nuclear spin relaxation properties in terms of microdynamic parameters. Magnetic relaxation times T1, T2, and NOE depend on dipolar and quadrupolar interactions, on chemical shift anisotropy and cross-correlation effects. Within the framework of given motional ...
The history of nucleon scattering experiments is reviewed, starting with the observation of large proton polarizations in scattering from light elements such as carbon, and ending with the acceleration of polarized proton beams in high-energy synchrotrons. Special mention is made about significant contributions made by C.L. Oxley, L. Wolfenstein, R.D. Tripp, T. Ypsilantis, A. ...
DOE Information Bridge
The temperature dependence of the differential anisotropy as a function of time was measured for the 133-482-kev cascade in Ta/sup 181/ that resulted from Hf/sup 181/ activity obtained bv neutron irradiation of Hf metal. Results indicate that the electric quadrupole interaction frequency depends on the temperature (integral anisotropies and interaction frequencies are given). The ...
A nuclear induction magnetometer for measuring small magnetic fields, e.g., earth's magnetic field, is designed which is based on the Overhauser- Abragam effect. This effect, which involves the addition to the liquid sample of a paramagnetic substance having hyperfine structure, enables not only the reduction of the intensity of the auxiliary biasing magnetic ...
HolkB Ts) where Ts = ~8" ~ is the spin temperature in an applied magnetic field Ho. Thus in lithium hydride un �chantillon de deut�riure de lithium 6LiD pour les spins nucl�aires de lithium et de deut�rium % have been obtained in a sample of 6LiD, for the nuclear spins of lithium and deuterium. These results
E-print Network
The study attempts to verify the theory of Abragam and Borghini based on the concept of spin temperature. The theory predicts the enhancement of nuclear polarization in solids in which a paramagnetic electron system is also present. Verification of this theory was sought using the substance CaF2 doped with Yb. By studying the epr lineshape of the Yb(3+) ions, its homogeneity, ...
>Recently it was pointed out by Dillenburg and Maris that the application of first-order perturbation theory in the treatment by Abragam and Pound might not generally be correct. Deviations might result in those cases where one single interaction is strong enough to cause a reasonable change in the spin state. Dillenburg and Maris used in their calculations only ...
Proton polarization up to 80% has been achieved with the University of Massachusetts ''spin regrigerator'' in a nonuniform 1.07-T field at 1.25 K. The free protons in (Yb, Y) (C/sub 2/H/sub 5/SO/sub 4/)/sub 3/x9H/sub 2/O are polarized through sample rotation at approximately 100 rps. Results represent the first confirmation of high polarization predicted by a ...
The influence of independent processes of relaxation of paramagnetic ions on nuclear magnetic relaxation in the presence of these ions is discussed theoretically, using the Kubo and Tomita method. The nuclei are assumed to relax as a result of their contact with the ions through the usual dipole-dipole mechanism and this irteraction is, in turn, considered to be of negligible influence ...
We have experimentally studied the first and the second moments of D, 6Li and 7Li (I>1/2) NMR lines in a granulated LiD-target material as a function of nuclear polarizations and the data has been compared with a theory elaborated by Abragam, Roinel and Bouffard for monocrystalline samples. The experiments were carried out in the large COMPASS twin-target at CERN. The ...
Measurements are reported on the successful orientation of 26-hour As/ sup 76/ donors in a doped silicon crystal. A general discussion is given of the various methods of dynamic nuclear orientation and how they apply to As/sup 76/. The use of radio-frequency orientation to determine the sign of the nuclear magnetic moment and the mixture of total angular momenta carried off by the ...
Enhancements of ^129Xe NMR signals up to 300 times their equilibrium value at temperature 2.0K and magnetic field � 0.3T, corresponding to a spin polarization >1%, have been obtained in solid xenon with TEMPO^1 impurity concentrations near 10^18 /cm^3. This dynamic polarization results from interaction of the nuclear Zeeman spin reservoir with the electron spin-spin reservoir^2, while ...
S>The quadrupolar deformation of heavy nuclei was studied experimentally. The theoretical aspects of deformation of nuclei and probability of gamma transition, together with angnlar correlations and internal conversion, are discussed. The methods used for the analysis of alpha , BETA , and gamma radiation and for the measurement of the mean lifetime of excited states are ...
I have understood my assignment as a review of some of the work done in high-energy physics with polarized proton targets and a description of some of the special problems connected with polarized targets. Most of my report will be based on the polarized target that I am most familiar with--that constructed by Jeffries, Schultz, Shapiro, and myself. This target is no longer unique; in fact, it is ...
Magnetic resonance imaging (MRI) of materials is a field of increasing importance. Applications extend from fundamental science like the characterization of fluid transport in porous rock, catalyst pellets and hemodialysers into various fields of engineering for process optimization and product quality control. While the results of MRI imaging are being appreciated by a growing community, the ...
About ionospheric models. General Models ... Chiu Ionospheric Model � Bent Ionospheric Model � Penn State Mk III Model � SLIM Model � FAIM Model ...
models, radiation transport models, atomic and nuclear physics models, vehicle and human body models, and radiation effects models. ...
many models of human behavior with environment models, equipment models, and procedural / task models. The challenge to model comprehensibility is ...
