Cross section models for cold neutron scattering from liquid hydrogen and liquid deuterium

1994 ◽  
Vol 350 (1-2) ◽  
pp. 275-285 ◽  
Author(s):  
N. Morishima ◽  
D. Mizobuchi
Keyword(s):  
Neutron Scattering ◽  
Cross Section ◽  
Cold Neutron ◽  
Liquid Hydrogen

scholarly journals Development of neutron scattering kernels for cold neutron reflector materials

2021 ◽  
pp. 1-11
Author(s):  
José Rolando Granada ◽  
José Ignacio Márquez Damián ◽  
Javier Dawidowski ◽  
José Ignacio Robledo ◽  
Christian Helman ◽  
...  
Keyword(s):  
Neutron Scattering ◽  
Cross Section ◽  
Cold Neutron ◽  
Nuclear Industry ◽  
Cross Section Data ◽  
Design And Optimization ◽  
Section Data ◽  
Diamond Nanopowder ◽  
Physics Department ◽  
Fission Reactors

The newest neutron scattering applications are highly intensity-limited techniques that demand reducing the neutron losses between source and detectors. In addition, the nuclear industry demands more accurate data and procedures for the design and optimization of advanced fission reactors, especially for the treatment of fuel and moderator materials. To meet these demands, it is necessary to improve the existing calculation tools, through the generation of better models that describe the interaction of neutrons with the systems of interest. The Neutron Physics Department at Centro Atomico Bariloche (CNEA, Argentina) has been developing over the time new models for the interaction of slow neutrons with materials, to produce scattering kernels and cross section data in the thermal and cold neutron energy region. Besides the studies carried out on neutron moderators, we have recently begun looking at materials that could serve as efficient neutron reflectors over those energy ranges. In this work we present the results of transmission and scattering experiments on diamond nanopowder and magnesium hydride, carried out simultaneously at the VESUVIO spectrometer (ISIS, UK), and compare them with newly generated cross-section libraries.

THEORY OF COLD NEUTRON SCATTERING BY HOMONUCLEAR DIATOMIC LIQUIDS: I. FREE ROTATION

1966 ◽  
Vol 44 (6) ◽  
pp. 1279-1297 ◽  
Author(s):  
V. F. Sears
Keyword(s):  
Neutron Scattering ◽  
Cross Section ◽  
Born Approximation ◽  
Cold Neutron ◽  
Intermolecular Forces ◽  
Inert Gases ◽  
Jones Potential ◽  
Lennard Jones ◽  
Law Of Corresponding States ◽  
Homonuclear Diatomic Molecules

The cold neutron scattering cross section for a system of homonuclear diatomic molecules with arbitrary nuclear spin and an arbitrary ortho–para ratio is calculated in first Born approximation, assuming that the molecular rotation is unhindered. The cross section is expressed in the form of an expansion in terms of the angular momentum transfer. This expansion is shown to be rapidly convergent for all the permanent homonuclear diatomic liquids. To the extent that the intermolecular forces are described by an isotropic Lennard-Jones potential, the terms in the expansion can be calculated with the help of the law of corresponding states and the observed scattering functions for the condensed inert gases. The problem of neutron diffraction by homonuclear diatomic liquids is also investigated.

THEORY OF COLD NEUTRON SCATTERING BY HOMONUCLEAR DIATOMIC LIQUIDS: II. HINDERED ROTATION

1966 ◽  
Vol 44 (6) ◽  
pp. 1299-1311 ◽  
Author(s):  
V. F. Sears
Keyword(s):  
Distribution Function ◽  
Neutron Scattering ◽  
Partial Wave ◽  
Cross Section ◽  
Cold Neutron ◽  
Rotational Relaxation ◽  
Free Rotation ◽  
Hindered Rotation ◽  
Orientational Distribution ◽  
Orientational Distribution Function

The partial wave expansion of the cold neutron scattering cross section for a homonuclear diatomic liquid in terms of the angular momentum transfer, which was introduced in a previous article for the case of free rotation, is generalized to include hindered rotation. The cross section is expressed in terms of an orientational distribution function that is the rotational analogue of the Van Hove self-correlation function. The rotational scattering function for the lth partial wave is shown to be the Fourier transform of a rotational relaxation function, Fl(t), which is also the lth coefficient of the expansion of the orientational distribution function in terms of spherical harmonics. The functions Fl(t) are calculated for the limiting cases of free rotation and rotational diffusion. The problem of neutron diffraction by homonuclear diatomic liquids is also investigated, and it is shown that the small angle scattering is determined by the isothermal compressibility. This is a generalization of the well-known result for monatomic liquids.

Cold-neutron scattering cross section and hydrogen mobility in zirconium hydride

1983 ◽  
Vol 55 (3) ◽  
pp. 603-605
Author(s):  
B. E. Zhitarev ◽  
S. B. Stepanov ◽  
Yu. B. Zasadych
Keyword(s):  
Neutron Scattering ◽  
Cross Section ◽  
Cold Neutron ◽  
Scattering Cross Section ◽  
Zirconium Hydride ◽  
Scattering Cross

Instrumentation for Neutron Scattering at the National Institute of Standards and Technology

1994 ◽  
Vol 376 ◽  
Author(s):  
W.A. Kamitakahara ◽  
Jj. Rush ◽  
J.M. Rowe ◽  
Hj. Prask
Keyword(s):  
Neutron Scattering ◽  
Thermal Neutron ◽  
Neutron Beam ◽  
Cold Neutron ◽  
Liquid Hydrogen ◽  
Research Facility ◽  
Cold Source ◽  
Wide Range ◽  
Neutron Guides ◽  
The U.S

ABSTRACTThe National Institute of Standards and Technology (NIST) offers a wide range of neutron beam instruments to the U.S. community. Many of these are of recent construction, and are located in the Cold Neutron Research Facility, a large guide hall with fifteen experimental stations on seven neutron guides. A new liquid hydrogen cold source is being installed. Thermal neutron instruments in the reactor confinement are to be upgraded over the next few years.

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