Theory of phase transitions in solid methanes. XIV. The total neutron scattering cross section in phase II of solid CH4

1981 ◽  
Vol 59 (2) ◽  
pp. 275-282 ◽  
Author(s):  
Yoshiaki Ozaki ◽  
Yosuke Kataoka ◽  
Kenkichi Okada ◽  
Tsunenobu Yamamoto
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Phase Ii ◽  
Single Molecule ◽  
Neutron Cross Section ◽  
Proton Spin ◽  
Total Neutron ◽  
Rotational States ◽  
Future Experimental Study ◽  
The Mean

The total neutron cross section in phase II of solid CH4 is calculated as a function of the incident energy E0 and the temperature in the ranges [Formula: see text] and [Formula: see text]. The sample is assumed to be a polycrystal and the neutron beam to be unpolarized. The total cross section consists of two parts: proton spin-independent and dependent parts. The latter is given by a sum of σ0 and σ′. Both the spin-independent part and σ0 come from the elastic scattering and can together be cast in the form [Formula: see text] for both Oh andD2d molecules, where [Formula: see text] is the mean squared proton spin angular momentum within a single molecule. The quantity σ′ depends on the details of the spin–rotational states. The calculated total cross section can again be expressed approximately as a linear function of [Formula: see text] as was empirically found by Lushington and Morrison (Can. J. Phys. 55, 1580 (1977)). A prediction is offered for a possible future experimental study.

scholarly journals Total Cross Section of the n+11B Reaction

2020 ◽  
Vol 4 ◽  
pp. 13
Author(s):  
G. Galios ◽  
G. Doukelis ◽  
S. Kossionides ◽  
T. Paradellis
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Reaction Rate ◽  
Neutron Cross Section ◽  
Total Neutron ◽  
Cross Section Data ◽  
Total Neutron Cross Section ◽  
Section Data ◽  
Upper Limit ◽  
Stellar Reaction Rate

The total neutron cross section of 11Β has been measured from 7.2 to 8.4 MeV. The analysis of all data from the 8Li(α,n0)11Β reaction in combination with the total cross section data can determine an upper limit on the stellar reaction rate of the 8Li(a,n)11Β reaction.

Neutron scattering and proton spin conversion in solid CH4

1977 ◽  
Vol 55 (18) ◽  
pp. 1580-1588 ◽  
Author(s):  
K. J. Lushington ◽  
J. A. Morrison
Keyword(s):  
Cross Section ◽  
Solid Phase ◽  
Wave Length ◽  
Neutron Cross Section ◽  
Spin Symmetry ◽  
Proton Spin ◽  
Spin Conversion ◽  
Temperature Dependences ◽  
Symmetry Species ◽  
The Mean

The total neutron cross section of pure and O2-doped condensed CH4 has been measured in the temperature range 0.75 < T < 100 K. The neutron wave length was sufficiently long (4.7 Å) so that changes in cross section could be directly related to changes in [Formula: see text], the mean squared proton nuclear angular momentum per molecule, to a sensitivity of about 1%. The temperature dependences of [Formula: see text] for the pure and doped specimens differ considerably in solid phase II (T < 20.4 K). For the former specimen, the change in cross section is consistent with conversion occurring between the nuclear spin symmetry species on the orientationally disordered sublattices only. The addition of oxygen enhances the rate of conversion such that the value of [Formula: see text] corresponds to conversion on both the disordered and ordered sublattices. The characteristic lifetimes of the catalyzed and uncatalyzed conversion processes have been estimated.

The total neutron cross-sections of cobalt, silver, iodine, aluminium, nickel and gallium between 1 eV and 5 keV

1952 ◽  
Vol 215 (1121) ◽  
pp. 278-289 ◽  
Keyword(s):  
Total Cross Section ◽  
Cross Section ◽  
Cross Sections ◽  
Neutron Cross Section ◽  
Total Neutron ◽  
Total Neutron Cross Section ◽  
Energy Research ◽  
Main Interest ◽  
Neutron Time ◽  
Neutron Cross Sections

This paper presents experimental results of total neutron cross-section measurements made with a neutron time of flight spectrometer at the Atomic Energy Research Establishment, Harwell. Six elements, Co, Ag, I, Al, Ni and Ga, have so far been studied over the range of neutron energies from 1 eV to 5 keV. The main interest of the measurements lies in the use of improved resolution at the higher energies with the result that certain levels have now been more clearly resolved. The results are presented as curves showing the variation of total cross-section with neutron energy. For certain levels, the strength of the resonance is calculated. The spectrometer is briefly described and some reference made to previous work in the same field.

Investigation of the total neutron cross section for natural hafnium on the filtred neutron beam with energy 59 keV

2011 ◽  
Vol 30 (0) ◽  
pp. 142-147
Author(s):  
О. О. Грицай ◽  
А. К. Гримало ◽  
В. В. Колотий ◽  
В. М. Венедиктов ◽  
С. П. Волковецький ◽  
...  
Keyword(s):  
Cross Section ◽  
Neutron Beam ◽  
Neutron Cross Section ◽  
Total Neutron ◽  
Total Neutron Cross Section

Total Neutron Cross Section of Deuterium below 1000 keV

1972 ◽  
Vol 29 (26) ◽  
pp. 1745-1748 ◽  
Author(s):  
P. Stoler ◽  
N. N. Kaushal ◽  
F. Green ◽  
Edward Harms ◽  
Luciano Laroze
Keyword(s):  
Cross Section ◽  
Neutron Cross Section ◽  
Total Neutron ◽  
Total Neutron Cross Section

Total Neutron Cross Section forC12from 500 kev to 1350 kev

1960 ◽  
Vol 117 (4) ◽  
pp. 1055-1056 ◽  
Author(s):  
C. M. Huddleston ◽  
R. O. Lane ◽  
L. L. Lee ◽  
F. P. Mooring
Keyword(s):  
Cross Section ◽  
Neutron Cross Section ◽  
Total Neutron ◽  
Total Neutron Cross Section

Total neutron cross-section of Gd for 16–19 MeV neutrons

1969 ◽  
Vol 23 (2) ◽  
pp. 113-115 ◽  
Author(s):  
M. Hussain ◽  
R. Chaudhuri ◽  
M. Enayetullah ◽  
E. Islam
Keyword(s):  
Cross Section ◽  
Neutron Cross Section ◽  
Total Neutron ◽  
Total Neutron Cross Section
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