scholarly journals Magnetism and Neutron Scattering

1997 ◽  
Vol 50 (6) ◽  
pp. 1119
Author(s):  
T. J. Hicks
Keyword(s):  
Magnetic Material ◽  
Neutron Scattering ◽  
Cross Sections ◽  
Magnetic Dipole Moment ◽  
Degree Of Approximation ◽  
Magnetic Parameters ◽  
The Moment ◽  
High Degree ◽  
Scattering Cross Sections ◽  
Very High

Magnetic neutron scattering is very closely connected to the fundamental magnetic quantities of magnetisation and susceptibility. This is because, to a very high degree of approximation which becomes exact at long neutron wavelengths, the interaction of the neutron magnetic dipole moment is with the local magnetic induction in the magnetic material. The strength of neutron scattering for the investigation of magnetic materials lies in this and the facility of the technique to probe Fourier components of the moment and the susceptibility with wavelengths down to atomic distances, as well as to probe susceptibility fluctuation time scales the same as those that are thermally excited. This paper provides a concise account of the formal connection between neutron scattering cross sections and more familiar bulk magnetic parameters.

Correction method for the asymmetry of the tangential beam in Couette (or Searle) geometry used in rheo-small-angle neutron scattering

2004 ◽  
Vol 37 (3) ◽  
pp. 438-444 ◽  
Author(s):  
Florian Nettesheim ◽  
Ulf Olsson ◽  
Peter Lindner ◽  
Walter Richtering
Keyword(s):  
Neutron Scattering ◽  
Cross Sections ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Correction Method ◽  
Shear Cell ◽  
The Asymmetry ◽  
The Difference ◽  
Scattering Cross Sections ◽  
Final Expression

A method of correcting the asymmetry in the scattering of the tangential beam configuration in a rheo-small-angle neutron scattering experiment is proposed. The asymmetry of the scattering in the tangential beam configuration can be attributed to the difference in pathlength for neutrons that are scattered toward compared with those which are scattered away from the axis of rotation of the shear cell. The pathlength problem is solved and a final expression for the two-dimensional scattering intensity is given. The results from these calculations are compared with experimental data, which offer a different option to correct this asymmetry, namely by just measuring the scattering of H2O/D2O mixtures with absolute scattering cross sections identical to those of the respective samples. However, the situation for anisotropic media is more complex and the correction procedure described here is less effective.

scholarly journals A search for deviations from the inverse square law of gravity at nm range using a pulsed neutron beam

2019 ◽  
Vol 219 ◽  
pp. 05002
Author(s):  
Christopher Haddock ◽  
Katsuya Hirota ◽  
Takashi Ino ◽  
Masaaki Kitaguchi ◽  
Kenji Mishima ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Cross Sections ◽  
Noble Gases ◽  
Scattering Length ◽  
Slow Neutron ◽  
Inverse Square Law ◽  
Scattering Cross ◽  
Law Of Gravity ◽  
Neutron Momentum ◽  
Scattering Cross Sections

Recently published results and ongoing experimental efforts to search for deviations from the inverse square law of gravity at the nanometer length scale using slow neutron scattering from the noble gases are discussed. Using the pulsed slow neutron beamline BL05 at the Materials and Life Sciences Facility at J-PARC, we measured the neutron momentum transfer (q) dependence of the differential scattering cross section for the noble gases He, Ne, Ar, Kr, and Xe. By comparing to the distributions obtained using pseudo-experimental Monte Carlo simulations and forming ratios between Xe and He, we placed an upper bound on the strength of a new interaction as a function of interaction length λ which improved upon previous results in the region λ < 0.1 nm, and remains competitive in the larger λ region. Additionally we describe how we are using our technique to extract relative values of the total neutron scattering cross sections of the noble gases, as well as how we plan to measure the neutron-electron scattering length using the NOVA instrument on BL21 at J-PARC.

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