Neutron Absorption Cross Section (Sigma) of Basaltic Basement Samples from Hole 896A, Costa Rica Rift

1996 ◽  
Author(s):  
T.S. Brewer ◽  
P.K. Harvey ◽  
J. Locke ◽  
M.A. Lovell
Keyword(s):  
Costa Rica ◽  
Cross Section ◽  
Absorption Cross Section ◽  
Neutron Absorption ◽  
Absorption Cross ◽  
Neutron Absorption Cross Section

THERMAL NEUTRON ABSORPTION CROSS SECTION OF Xe135

1959 ◽  
Vol 37 (5) ◽  
pp. 531-536 ◽  
Author(s):  
H. R. Fickel ◽  
R. H. Tomlinson
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Mass Spectrometer ◽  
Absorption Cross Section ◽  
Yield Ratio ◽  
Neutron Absorption ◽  
Absorption Cross ◽  
Fission Yield ◽  
Effective Neutron ◽  
Neutron Absorption Cross Section

The effective neutron absorption cross section of Xe135 has been measured with a mass spectrometer by observing the variation in the Cs135/Cs137 fission yield ratio obtained at various thermal neutron fluxes. Values of 3.15 ± 0.06 megabarns and 3.27 ± 0.11 megabarns have been determined for neutron temperatures of 120 °C and 137 °C respectively.

Measurement of the Thermal Neutron Absorption Cross Section of Rock Samples

1983 ◽  
pp. 143-151
Author(s):  
J.A. CZUBEK ◽  
K. DROZDOWICZ ◽  
E. KRYNICKA-DROZDOWICZ ◽  
A. IGIELSKI ◽  
U. WOźNICKA
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Absorption Cross Section ◽  
Neutron Absorption ◽  
Absorption Cross ◽  
Rock Samples ◽  
Neutron Absorption Cross Section

Gadolinium tracers for enhancement of Sigma-log contrast measurements

Geophysics ◽  
2017 ◽  
Vol 82 (1) ◽  
pp. EN13-EN24 ◽  
Author(s):  
Christopher van der Hoeven ◽  
Matthew Montgomery ◽  
Gregory Sablan ◽  
Erich Schneider ◽  
Carlos Torres-Verdín
Keyword(s):  
Computational Modeling ◽  
Cross Section ◽  
Absorption Cross Section ◽  
Low Cost ◽  
Neutron Absorption ◽  
Absorption Cross ◽  
Porous Rocks ◽  
Doping Agent ◽  
Wide Range ◽  
Neutron Absorption Cross Section

Borehole neutron measurements are routinely used for in situ rock assessment in hydrocarbon reservoirs. We have used gadolinium oxide nanoparticles for enhancing the sensitivity of macroscopic thermal neutron absorption cross-section (Sigma) measurements of rocks. The gadolinium-based doping agent is used due to its exceptionally high neutron absorption cross section, low cost, and availability; it is also shown to preserve or enhance the differentiation between pore fluids. Injected from a pilot well, the doping agent could thus substantially improve the precision of Sigma-derived saturation measurements. Computational modeling verifies that modest gadolinium concentrations in the rock’s pore volume give rise to significant enhancement of reported Sigma: A concentration of 1750 weight ppm is shown to offer superior contrast enhancement across a wide range of rock solid and fluid compositions. Preliminary experimental work confirms the reported effects obtained with computational modeling of gadolinium doping in simulated porous rocks.

THE FISSION YIELDS OF THE CESIUM ISOTOPES FORMED IN THE THERMAL NEUTRON FISSION OF U235 AND THE NEUTRON ABSORPTION CROSS SECTION OF Xe135

1955 ◽  
Vol 33 (11) ◽  
pp. 640-649 ◽  
Author(s):  
J. A. Petruska ◽  
E. A. Melaika ◽  
R. H. Tomlinson
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Isotope Dilution ◽  
Absorption Cross Section ◽  
Neutron Absorption ◽  
Absorption Cross ◽  
Neutron Fission ◽  
Thermal Neutron Fission ◽  
Fission Yields ◽  
Neutron Absorption Cross Section

The absolute fission yields of the cesium isotopes occurring in the thermal neutron fission of U235 have been determined with a mass spectrometer using isotope dilution techniques. Values of 6.59%, 6.41%, and 6.15% have been obtained for the yields of Cs133, Cs135, and Cs137 respectively. The neutron absorption cross section of Xe135 has also been measured to be 866 times greater than that of B10 for a Maxwellian distribution of neutron velocities corresponding to a neutron temperature of 57 °C. This ratio gives a thermal neutron absorption cross section of 3.47 × 106 barns for Xe135 assuming it is a 1/ν detector.

Thermal neutron absorption cross-section for small samples: experiments in spherical geometry

1981 ◽  
Vol 14 (6) ◽  
pp. 977-984 ◽  
Author(s):  
J A Czubek ◽  
K Drozdowicz ◽  
A Igielski ◽  
E Krynicka-Drozdowicz ◽  
Z Sobczynski ◽  
...  
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Absorption Cross Section ◽  
Spherical Geometry ◽  
Small Samples ◽  
Neutron Absorption ◽  
Absorption Cross ◽  
Neutron Absorption Cross Section
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