REACTOR NEUTRON-CAPTURE CROSS SECTION OF 18-MINUTE Rb88

1958 ◽  
Vol 36 (5) ◽  
pp. 731-736 ◽  
Author(s):  
J. C. Roy ◽  
P. J. Berry ◽  
L. P. Roy
Keyword(s):  
Beta Decay ◽  
Cross Section ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Activation Method ◽  
Reactor Neutron ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
The Cross ◽  
Thermal Cross Section

The reactor neutron-capture cross section of 18-minute Rb88 has been determined by an activation method. The yield of Rb89 formed by successive neutron capture in Rb87 was determined by counting the beta rays emitted by its daughter, 51-day Sr89. In these experiments Sr89 is also produced by the Sr88(n, γ)Sr89 reaction from the Sr88 contamination in the rubidium target and from Sr88 formed by the beta decay of Rb88. Corrections for the contributions from these sources to the yield of Sr89 have been measured experimentally. The reactor neutron-capture cross section of Sr88 has been measured to be 5.8 mb. for the conditions of the experiment. Taking 0.12 ± 0.3 barn for the thermal cross section of Rb87, the cross section of Rb88 was found to be 1.0 ± 0.3 barn for reactor neutrons.

THERMAL NEUTRON CAPTURE CROSS SECTION OF Ce142

1956 ◽  
Vol 34 (8) ◽  
pp. 1023-1026 ◽  
Author(s):  
L. P. Roy ◽  
L. Yaffe
Keyword(s):  
Thermal Neutron ◽  
Cross Section ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Activation Method ◽  
Thermal Neutron Capture ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
A Value ◽  
The Cross

The cross section of Ce142 has been determined by the activation method and found to be 0.95 ± 0.05 barns relative to a value of σCo59 = 36.3 barns. Disintegration rates were determined by a 4π counter. The value obtained agrees with that of Katcoff etal. (1949) also obtained by the activation method but differs markedly from that of Pomerance (1952).

THE "REACTOR" NEUTRON CAPTURE CROSS SECTION OF Y91

1960 ◽  
Vol 38 (12) ◽  
pp. 1690-1701
Author(s):  
Gwen M. Milton ◽  
W. E. Grummitt
Keyword(s):  
Cross Section ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Specific Activity ◽  
High Specific Activity ◽  
Natural Uranium ◽  
Reactor Neutron ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
Chemical Purification

A high specific activity source of Y91, freed from natural uranium and rare earths, was irradiated in a high flux position in the NRX reactor. After further chemical purification, 3.6-hour Y92 was identified in the sample by measurement of the 3.6-Mev β-particle associated with its decay, using a scintillation spectrometer. Two such measurements have established the reactor neutron capture cross section of Y91 to be 1.4 ± 0.3 barns.

scholarly journals Work on the neutron standards since the completion of the standards evaluation

2020 ◽  
Vol 239 ◽  
pp. 08001
Author(s):  
Allan Carlson
Keyword(s):  
Cross Section ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Neutron Cross Section ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
Paper Work ◽  
The Cross

An evaluation of the neutron standards that included the neutron cross section standards was recently completed. It is important to maintain experimental programs to increase the quality and extend the database for the neutron cross section standards in order to improve evaluations of them. In this paper work will be reported on new or continuing efforts on the cross section standards including that on the 30 keV Maxwellian averaged cross section for the 197Au(n,γ) reaction that is now a standard and is used in neutron capture cross section measurements as a standard for reactions important for astrophysics.

THE REACTOR NEUTRON CAPTURE CROSS SECTION OF 124Sb

1966 ◽  
Vol 44 (11) ◽  
pp. 2956-2959 ◽  
Author(s):  
R. Courtemanche ◽  
T. A. Eastwood ◽  
R. D. Werner
Keyword(s):  
Cross Section ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Reactor Neutron ◽  
Capture Cross ◽  
Neutron Capture Cross Section

THE REACTOR NEUTRON CAPTURE CROSS SECTION OF Ag110m

1963 ◽  
Vol 41 (8) ◽  
pp. 1321-1331
Author(s):  
R. G. Hart ◽  
R. L. Graham
Keyword(s):  
Neutron Flux ◽  
Cross Section ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Thermal Neutron Flux ◽  
Reactor Neutron ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
A Value ◽  
Measured Ratio

Natural silver has been irradiated for 75.3 days in a thermal neutron flux of 2.42 × 1014 cm−2 sec−1 and the complex beta-ray spectrum of the resulting activities of 249-day Ag110m and 7.5-day Ag111 have been studied with a magnetic spectrometer. From the measured ratio of the respective beta-ray intensities and using the currently accepted decay schemes of these nuclides a value of 82 ± 11 barns is obtained for the reactor neutron capture cross section of Ag110m. Possible causes of systematic error are discussed.

NEUTRON CAPTURE CROSS SECTION OF I129 AND I130

1958 ◽  
Vol 36 (10) ◽  
pp. 1424-1430 ◽  
Author(s):  
J. C. Roy ◽  
D. Wuschke
Keyword(s):  
Cross Section ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Resonance Capture ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
Thermal Cross Section

The capture cross section of I129 for 2200 m/sec neutrons and its resonance capture integral were determined by counting the beta rays emitted by the 12.5-hour I130 formed by an (n, γ) reaction on I129. The σ2200 was found to be 26.7 ± 2.0 barns and the resonance capture integral 36 ± 4.0 barns. The effective capture cross section of I130 for reactor neutrons was measured to be 18.0 ± 3.0 barns by counting the beta rays emitted by the 8.1-day I131 produced by successive neutron capture in I129. The neutron fluxes were measured with cobalt monitors; the thermal cross section and the resonance capture integral of Co59 were taken to be 36.5 and 48.6 barns.

SEARCH FOR SUCCESSIVE NEUTRON CAPTURE REACTIONS ON Mg26, Si30, AND Cr54

1957 ◽  
Vol 35 (2) ◽  
pp. 176-179 ◽  
Author(s):  
L. P. Roy ◽  
L. Yaffe
Keyword(s):  
Cross Section ◽  
Neutron Capture ◽  
Capture Cross Section ◽  
Second Order ◽  
Capture Cross ◽  
Neutron Capture Cross Section ◽  
Maximum Value ◽  
The Cross ◽  
Intense Neutron ◽  
Stable Nuclides

Stable nuclides exposed to intense neutron fluxes may produce second order reactions by successive capture of two neutrons. This method has been applied in the present work in an attempt to determine the pile neutron capture cross section of three unstable nuclides, namely: Mg27, Si31, and Cr55. A maximum value of 0.04 barn has been obtained for the cross section of Mg27. Assuming that Si32 and Cr56 are long-lived, minimal ratios of 600 and 270 years/barn respectively were obtained for [Formula: see text]

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