scholarly journals The capture cross-section for thermal neutrons of the nucleus C13 and the half-life of C14

1942 ◽  
Author(s):  
Martin D. Kamen
Keyword(s):  
Cross Section ◽  
Half Life ◽  
Capture Cross Section ◽  
Thermal Neutrons ◽  
Capture Cross

THERMAL NEUTRON CAPTURE CROSS-SECTION OF Na23 AND Mn55

1953 ◽  
Vol 31 (3) ◽  
pp. 204-206 ◽  
Author(s):  
Rosalie M. Bartholomew ◽  
R. C. Hawkings ◽  
W. F. Merritt ◽  
L. Yaffe
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Cross Sections ◽  
Neutron Capture ◽  
Half Life ◽  
Capture Cross Section ◽  
Thermal Neutron Capture ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
Capture Cross Sections

The thermal neutron capture cross sections of Na23 and Mn55 have been determined using the activation method. The values are 0.53 ± 0.03 and 12.7 ± 0.3 barns respectively with respect to σAul97 = 93 barns. These agree well with recent pile oscillator results. The half-life for Mn56 is found to be 2.576 ± 0.002 hr.

THE THERMAL NEUTRON CAPTURE CROSS SECTION OF AU198 AND THE HALF-LIFE OF AU199

1955 ◽  
Vol 33 (8) ◽  
pp. 457-465 ◽  
Author(s):  
R. E. Bell ◽  
R. L. Graham ◽  
L. Yaffe
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Neutron Capture ◽  
Half Life ◽  
Capture Cross Section ◽  
Neutron Cross Section ◽  
Thermal Neutron Capture ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
Thermal Neutron Cross Section

The thermal neutron capture cross section of radioactive Au198 has been measured by the activation method as 26,000 ± 1200 barns, assuming 99 barns for the thermal neutron cross section of Au197. Metallic Au197 was bombarded in fluxes up to 9 × 1013 thermal neutrons cm.−2 sec.−1 to produce a mixture of Au198 and Au199 by the successive neutron capture reactions Au197(n, γ)Au198(n, γ)Au199. The ratio of the Au199 activity to Au198 activity so produced yields σc(Au197). In a preliminary experiment, the half-life of Au199 was measured as 3.148 ± 0.010 days.

Effective neutron capture cross section and half-life of 155Eu

1970 ◽  
Vol 48 (16) ◽  
pp. 1933-1935 ◽  
Author(s):  
R. S. Mowatt
Keyword(s):  
Cross Section ◽  
Neutron Capture ◽  
Absorption Cross Section ◽  
Half Life ◽  
Capture Cross Section ◽  
Capture Cross ◽  
Absorption Cross ◽  
Neutron Capture Cross Section ◽  
Effective Neutron

The half-life of 155Eu has been measured to be 4.65 ± 0.20 years and the absorption cross section has been found to be 4040 ± 125 b by a depletion method using a Ge(Li) detector. The sample of 155Eu was irradiated in the NRU pneumatic carrier where the flux has a small epithermal component. These values are very different from values of [Formula: see text] years and σ ~ 13 000 b reported previously.

AN ATTEMPT TO DETECT THE REACTION C14(n, γ)C15

1951 ◽  
Vol 29 (2) ◽  
pp. 186-192 ◽  
Author(s):  
L. Yaffe ◽  
W. H. Stevens
Keyword(s):  
Cross Section ◽  
Half Life ◽  
Capture Cross Section ◽  
Capture Cross

A search has been made for the reaction C14(n, γ) C15. We have been unable to find any activity ascribable to C15. If the β-ray energy of C15 is greater than 3 Mev. and the half life lies between 1 sec. and 1 min., the capture cross section for the above reaction is less than 1 microbarn.

THE CAPTURE CROSS-SECTION FOR THERMAL NEUTRONS OF CADMIUM, LITHIUM6, BORON10, BARIUM, MERCURY AND HYDROGEN

1941 ◽  
Vol 19a (3) ◽  
pp. 33-41 ◽  
Author(s):  
E. L. Harrington ◽  
J. L. Stewart
Keyword(s):  
Cross Section ◽  
Cross Sections ◽  
Capture Cross Section ◽  
Comparison Method ◽  
Thermal Neutrons ◽  
Capture Cross ◽  
Scattering Effect ◽  
Capture Cross Sections

A comparison method of measuring, by using solutions, the capture cross-sections for thermal neutrons is described. The chief advantages are directness, simplicity, and freedom from uncertainties as to direction of path, or as to the magnitude of the scattering effect. The method is best suited to nuclei of large cross-sections. Assuming the well checked value for the cadmium nucleus to be correct, the capture cross-sections of certain other nuclei were determined. The results for barium and for hydrogen differ widely from values previously published.

THE THERMAL NEUTRON CAPTURE CROSS SECTION AND THE RESONANCE ABSORPTION INTEGRAL OF Th230 (IONIUM)

1958 ◽  
Vol 36 (8) ◽  
pp. 989-996 ◽  
Author(s):  
M. J. Cabell
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Neutron Capture ◽  
Half Life ◽  
Capture Cross Section ◽  
Resonance Absorption ◽  
Thermal Neutron Capture ◽  
Resonance Capture ◽  
Capture Cross ◽  
Neutron Capture Cross Section

The thermal neutron capture cross section and the resonance capture integral of Th230 have been determined by an activation method. Assumptions are made that the thermal capture cross section and the resonance capture integral of Co59 are 36.5 barns and 48.6 barns respectively, that the half-life of Th230 is 8.00 × 104 years, and that Th230 behaves as a 1/v absorber in the subcadmium region. Based on these assumptions values of σ2200 = 21.4 ± 0.3 barns and of 937 ± 32 barns for the resonance absorption integral (from 0.5 ev to ∞) have been obtained for Th230.The half-life of Th231 has been determined as 25.52 ± 0.01 hours.

THE DIFFUSION LENGTH OF THERMAL NEUTRONS IN HEAVY WATER CONTAINING LITHIUM CARBONATE

1947 ◽  
Vol 25a (1) ◽  
pp. 26-41 ◽  
Author(s):  
H. G. Hereward ◽  
H. R. Paneth ◽  
G. C. Laurence ◽  
B. W. Sargent ◽  
A. M. Munn
Keyword(s):  
Cross Section ◽  
Heavy Water ◽  
Boron Trifluoride ◽  
Capture Cross Section ◽  
Diffusion Length ◽  
Lithium Carbonate ◽  
Mean Free Path ◽  
Thermal Neutrons ◽  
Capture Cross ◽  
Cylindrical Tank

The density distribution of thermal neutrons was measured with a small boron trifluoride chamber in a cylindrical tank containing 113 litres of heavy water in which lithium carbonate was dissolved. The diffusion length was found to be 22.7 cm. in this solution containing 7.70 × 10−4 atoms of lithium per molecule of heavy water (99.4 atom % D). After corrections were applied for the capture of neutrons in the heavy water and light hydrogen, the capture cross-section of lithium was found to be 59 × 10−24 cm.2 per atom for neutrons of standard velocity 2200 m. per sec. from the measured diffusion length and known transport mean free path.

scholarly journals Measurement of Effective Capture Cross Section of238Np for Thermal Neutrons

2004 ◽  
Vol 41 (1) ◽  
pp. 1-6 ◽  
Author(s):  
Hideo HARADA ◽  
Shoji NAKAMURA ◽  
Toshiyuki FUJII ◽  
Hajimu YAMANA
Keyword(s):  
Cross Section ◽  
Capture Cross Section ◽  
Thermal Neutrons ◽  
Capture Cross
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