Asymmetries for Elastic Scattering ofπ+from Polarized3Heand theΔ-Neutron Spin-Spin Interaction

1996 ◽  
Vol 76 (20) ◽  
pp. 3667-3670 ◽  
Author(s):  
M. A. Espy ◽  
D. Dehnhard ◽  
C. M. Edwards ◽  
M. Palarczyk ◽  
J. L. Langenbrunner ◽  
...  
Keyword(s):  
Elastic Scattering ◽  
Neutron Spin ◽  
Spin Interaction

Depolarization in p-15N elastic scattering and large tensor spin-spin interaction

1990 ◽  
Vol 240 (3-4) ◽  
pp. 301-305 ◽  
Author(s):  
T. Nakano ◽  
M. Nakamura ◽  
H. Sakaguchi ◽  
M. Yosoi ◽  
M. Ieiri ◽  
...  
Keyword(s):  
Elastic Scattering ◽  
Spin Interaction

Neutron-spin dynamics in elastic scattering on lead

2002 ◽  
Vol 65 (7) ◽  
pp. 1228-1235
Author(s):  
V. V. Vasiliev
Keyword(s):  
Elastic Scattering ◽  
Spin Dynamics ◽  
Neutron Spin

Enhanced nuclear magnetism: some novel features and prospective experiments

1983 ◽  
Vol 387 (1793) ◽  
pp. 221-256 ◽  
Keyword(s):  
Nuclear Polarization ◽  
Lattice Relaxation ◽  
Spin Lattice Relaxation ◽  
Neutron Spin ◽  
Spin Interaction ◽  
Nuclear Moment ◽  
Relaxation Rates ◽  
Nuclear Magnetism ◽  
Resonance Frequencies ◽  
Van Vleck

This review of enhanced nuclear magnetism discusses a number of features not previously considered, with special reference to new experiments that use dynamic methods to produce high nuclear polarization, followed by adiabatic demagnetization in the rotating frame (a. d. r. f.) to produce nuclear ordered states that may be investigated by the scattering of beams of neutrons. Section 2. The ‘enhancement’ of the nuclear moment arises from the electronic magnetization M I induced through the hyperfine interaction. It is shown that the spatial distribution of M I is the same as that of M H , the Van Vleck magnetization induced by an external field, provided that J is a good quantum number. The spatial distributions are not in general the same in Russell-Saunders coupling, e. g. in the 3d group. Section 3. The Bloch equations are extended to include anisotropic nuclear moments. Section 4. The ‘truncated’ spin Hamiltonian is derived for spin-spin interaction between enhanced moments. Section 5. A general cancellation theorem for second-order processes in spin-lattice relaxation is derived, showing that the intrinsic direct process must be of third order. The relaxation rate obeys an equation similar to that for Kramers electronic ions, but reduced as the fifth power of the resonance frequencies. The relaxation rates observed experimentally (except in very high fields) are ascribed to paramagnetic impurities, so that these can be used to produce dynamic nuclear polarization (d. n. p.). Section 6. The interactions of neutrons with the true nuclear moment μ I the Van Vleck moment M H , the ‘pseudonuclear’ moment M I and the ‘pseudomagnetic’ nuclear moment μ * I are discussed. It is shown that the four contributions can be observed separately by measurement of the form factor for neutron scattering as a function of temperature and direction of the applied magnetic field. Precession of the neutron spin in the ‘pseudomagnetic’ field H * is discussed with reference to the case of HoVO 4 , and an experiment on ‘pseudomagnetic resonance’ is proposed, in which the neutron spin is ‘flipped’ by resonance with the precessing H * of 169 Tm in TmPO 4 polarized by d. n. p. Section 7. Ordered states of enhanced nuclear moment systems are considered, together with the conditions under which they might be produced by a. d. r. f. following d. n. p. On the assumption that a transverse helical ordered structure can be created in TmPO 4 , a pseudomagnetic resonance experiment is suggested making use of 169 Tm, in which the neutron spin is flipped without the intervention of an external radio-frequency field.

scholarly journals Depolarization and the spin-spin interaction in p-9Be elastic scattering

1974 ◽  
Vol 53 (2) ◽  
pp. 165-167 ◽  
Author(s):  
J. Birchall ◽  
H.E. Conzett ◽  
J. Arvieux ◽  
W. Dahme ◽  
R.M. Larimer
Keyword(s):  
Elastic Scattering ◽  
Spin Interaction

Elastic Scattering in Electron Microscopy

1973 ◽  
Vol 31 ◽  
pp. 252-253
Author(s):  
J. Langmore ◽  
M. Isaacson ◽  
J. Wall ◽  
A. V. Crewe
Keyword(s):  
Electron Microscopy ◽  
Elastic Scattering ◽  
Cross Section ◽  
Quantum Noise ◽  
Dark Field ◽  
Elastic Cross Section ◽  
Biological Molecules ◽  
Dark Field Microscopy ◽  
Field Systems ◽  
Effects Of Radiation

High resolution dark field microscopy is becoming an important tool for the investigation of unstained and specifically stained biological molecules. Of primary consideration to the microscopist is the interpretation of image Intensities and the effects of radiation damage to the specimen. Ignoring inelastic scattering, the image intensity is directly related to the collected elastic scattering cross section, σɳ, which is the product of the total elastic cross section, σ and the eficiency of the microscope system at imaging these electrons, η. The number of potentially bond damaging events resulting from the beam exposure required to reduce the effect of quantum noise in the image to a given level is proportional to 1/η. We wish to compare η in three dark field systems.

The Resolution and Contrast in Biological Sections Determined by Inelastic and Elastic Scattering

1973 ◽  
Vol 31 ◽  
pp. 224-225
Author(s):  
D. L. Misell
Keyword(s):  
Electron Microscopy ◽  
Adverse Effect ◽  
Elastic Scattering ◽  
Inelastic Scattering ◽  
Amorphous Carbon ◽  
Polymeric Materials ◽  
Chromatic Aberration ◽  
Image Resolution ◽  
Quantitative Estimates ◽  
Elastic Ratio

In the electron microscopy of biological sections the adverse effect of chromatic aberration on image resolution is well known. In this paper calculations are presented for the inelastic and elastic image intensities using a wave-optical formulation. Quantitative estimates of the deterioration in image resolution as a result of chromatic aberration are presented as an alternative to geometric calculations. The predominance of inelastic scattering in the unstained biological and polymeric materials is shown by the inelastic to elastic ratio, I/E, within an objective aperture of 0.005 rad for amorphous carbon of a thickness, t=50nm, typical of biological sections; E=200keV, I/E=16.

A New Image Processing Technique for STEM

1974 ◽  
Vol 32 ◽  
pp. 432-433
Author(s):  
Yasushi Kokubo ◽  
Hirotami Koike ◽  
Teruo Someya
Keyword(s):  
Electron Microscopy ◽  
Image Processing ◽  
Scanning Electron Microscopy ◽  
Elastic Scattering ◽  
Field Emission ◽  
Processing Technique ◽  
Image Processing Technique ◽  
Energy Analyzer ◽  
Scanning Microscope ◽  
Scanning Electron

One of the advantages of scanning electron microscopy is the capability for processing the image contrast, i.e., the image processing technique. Crewe et al were the first to apply this technique to a field emission scanning microscope and show images of individual atoms. They obtained a contrast which depended exclusively on the atomic numbers of specimen elements (Zcontrast), by displaying the images treated with the intensity ratio of elastically scattered to inelastically scattered electrons. The elastic scattering electrons were extracted by a solid detector and inelastic scattering electrons by an energy analyzer. We noted, however, that there is a possibility of the same contrast being obtained only by using an annular-type solid detector consisting of multiple concentric detector elements.

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