THE THERMAL-NEUTRON FISSION YIELDS OF 229Th

1966 ◽  
Vol 44 (5) ◽  
pp. 1011-1019 ◽  
Author(s):  
J. W. Harvey ◽  
W. B. Clarke ◽  
H. G. Thode ◽  
R. H. Tomlinson
Keyword(s):  
Thermal Neutron ◽  
Isotope Dilution ◽  
Mass Spectrometric ◽  
Neutron Fission ◽  
Thermal Neutron Fission ◽  
Mass Group ◽  
The Absolute ◽  
Fission Yields ◽  
Mass Spectrometric Techniques

The relative cumulative yields for isotopes of the elements krypton, strontium, xenon, cesium, cerium, and neodymium formed in the thermal-neutron fission of 229Th have been determined by mass spectrometric techniques. Normalization of the relative yields by means of the isotope dilution and isobaric techniques has allowed estimates to be made of the absolute cumulative yields of the heavy-mass group by forcing the sum of the yields to total 100%.

THE ABSOLUTE FISSION YIELDS OF TWENTY-EIGHT MASS CHAINS IN THE THERMAL NEUTRON FISSION OF U235

1955 ◽  
Vol 33 (11) ◽  
pp. 693-706 ◽  
Author(s):  
J. A. Petruska ◽  
H. G. Thode ◽  
R. H. Tomlinson
Keyword(s):  
Fine Structure ◽  
Isotope Dilution ◽  
Yield Curve ◽  
Mass Yield ◽  
Absolute Accuracy ◽  
Neutron Fission ◽  
Thermal Neutron Fission ◽  
The Absolute ◽  
Fission Yields ◽  
Better Than

Twenty-eight absolute fission yields totalling 78% of the heavy and 16% of the light fragments have been determined using the mass spectrometer and isotope dilution techniques. The precision of the values obtained is in most cases better than 2% and the absolute accuracy is estimated to be about 3%. Fine structure in the mass–yield curve is discussed in terms of structural preference and various chain branching mechanisms.

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.

CUMULATIVE YIELDS OF THE HEAVY FRAGMENTS IN THE THERMAL-NEUTRON FISSION OF 241Pu

1964 ◽  
Vol 42 (11) ◽  
pp. 2063-2079 ◽  
Author(s):  
H. Farrar ◽  
W. B. Clarke ◽  
H. G. Thode ◽  
R. H. Tomlinson
Keyword(s):  
Fine Structure ◽  
Thermal Neutron ◽  
Isotope Dilution ◽  
Yield Curve ◽  
Mass Spectrometric ◽  
Mass Yield ◽  
General Shape ◽  
Neutron Fission ◽  
Yield Curves ◽  
Thermal Neutron Fission

The relative yields of isotopes of xenon, cesium, barium, cerium, neodymium, and samarium formed by the thermal neutron fission of 241Pu have been obtained by mass spectrometric methods. The relative yields of the elements were normalized by means of the isotope dilution and isobaric techniques, and absolute cumulative yields were determined by summing the relative yields to 100%. The curve obtained for 241Pu is compared with other mass–yield curves. The general shape of this mass–yield curve is similar to that for 239Pu; yet the fine structure shows greater similarity to that for 235U thermal-neutron fission.

THE THERMAL NEUTRON FISSION YIELDS OF U233

1961 ◽  
Vol 39 (3) ◽  
pp. 628-634 ◽  
Author(s):  
D. R. Bidinosti ◽  
D. E. Irish ◽  
R. H. Tomlinson
Keyword(s):  
Fission Product ◽  
Thermal Neutron ◽  
Mass Spectrometer ◽  
Isotope Dilution ◽  
Dilution Technique ◽  
Neutron Fission ◽  
Isotope Dilution Technique ◽  
Thermal Neutron Fission ◽  
Fission Yields

Using the mass spectrometer and isotope dilution technique, 27 cumulative fission yields from the thermal neutron fission of U233 along with 13 other fission product chains relative to each other have been determined. After normalization of the latter, values are obtained for all but seven fission decay chains whose yields are in excess of 0.5%.

THE CUMULATIVE FISSION YIELDS OF LIGHT MASS FRAGMENTS IN THE THERMAL NEUTRON FISSION OF Pu239

1959 ◽  
Vol 37 (8) ◽  
pp. 916-925 ◽  
Author(s):  
H. R. Fickel ◽  
R. H. Tomlinson
Keyword(s):  
Fission Product ◽  
Thermal Neutron ◽  
Mass Spectrometer ◽  
Isotope Dilution ◽  
Light Fragment ◽  
Neutron Fission ◽  
Fragment Mass ◽  
Thermal Neutron Fission ◽  
Fission Yields

The relative cumulative yields of 19 light mass fragments of rubidium, strontium, yttrium, zirconium, molybdenum, and ruthenium formed in the thermal neutron fission of Pu239 have been determined with a mass spectrometer using the isotope dilution technique.The yields of the fission product isotopes of these elements, together with the previously published relative yields of three krypton isotopes, have made possible the determination of the absolute yields of 22 light fragment mass chains.

SOME CUMULATIVE YIELDS OF ISOTOPES FORMED IN THE THERMAL NEUTRON FISSION OF Pu239

1956 ◽  
Vol 34 (3) ◽  
pp. 227-232 ◽  
Author(s):  
D. M. Wiles ◽  
J. A. Petruska ◽  
R. H. Tomlinson
Keyword(s):  
Thermal Neutron ◽  
Mass Spectrometer ◽  
Isotope Dilution ◽  
Neutron Fission ◽  
Thermal Neutron Fission ◽  
Xenon Isotopes ◽  
The Absolute

The relative yields of the isotopes of cesium, cerium, neodymium, and samarium produced by the thermal neutron fission of Pu239 have been determined with a mass spectrometer. Preliminary values of the absolute yields of 16 isotopes of these elements together with four yields of the xenon isotopes have been assigned by means of isotope dilution techniques.

Cumulative yields of stable and long-lived isotopes of ruthenium and palladium in neutron-induced fission

1978 ◽  
Vol 56 (10) ◽  
pp. 1340-1352 ◽  
Author(s):  
Masako Shima ◽  
H. G. Thode ◽  
R. H. Tomlinson
Keyword(s):  
Thermal Neutron ◽  
Isotope Dilution ◽  
Yield Curve ◽  
Mass Region ◽  
Mass Yield ◽  
Neutron Fission ◽  
Significant Depression ◽  
Thermal Neutron Fission ◽  
Induced Fission ◽  
Fission Yields

The relative cumulative yields of nine stable and long-lived isotopes of ruthenium and palladium (masses 101 to 110) produced in the thermal neutron fission of 233U and in the thermal and epicadmium neutron fission of 235U and 239Pu have been measured using a solid source mass spectrometer and isotope dilution techniques. Absolute yields of these isotopes for the thermal neutron fission of 233U, 235U, and 239Pu are obtained using normalization procedures. These yields provide the first experimentally determined yields of the palladium masses 105, 106, 107, 108, and 110.In the thermal fission of 233U and 235U the ruthenium isotope yields obtained are in general agreement with previously determined values, although discrepancies exist of the order of 10% at masses 103, 104, and 106 for thermal fission of 235U.A plot of the ruthenium and palladium isotope mass yields together with the previously determined yields for the cadmium and tin isotopes indicate a significant depression in the mass yield curve at masses 111 and 114 for 233U and 235U thermal fission, respectively. In the 235U epicadmium fission, yields at even mass numbers are relatively higher than those at odd numbers, resulting in a zigzag yield curve in the 101 to 110 mass region.

scholarly journals ABSOLUTE THERMAL NEUTRON FISSION YIELDS OF U233

1960 ◽  
Vol 38 (3) ◽  
pp. 421-438 ◽  
Author(s):  
D. C. Santry ◽  
L. Yaffe
Keyword(s):  
Neutron Flux ◽  
Thermal Neutron ◽  
Flux Monitor ◽  
Neutron Fission ◽  
Neutron Flux Monitor ◽  
Chemical Separations ◽  
Thermal Neutron Fission ◽  
Γ Ray ◽  
The Absolute ◽  
Fission Yields

The absolute fission yields of 22 nuclides formed in the thermal neutron fission of U233 have been measured radiochemically. Disintegration rates were measured by 4π β-proportional counting techniques. The identity of each nuclide was established by chemical separations and decay characteristics as determined by 4π β-counting and γ-ray scintillation spectrometry. The reaction Co59(n, γ)Co60 was used as a neutron flux monitor. Yields were calculated on the basis of [Formula: see text]

CUMULATIVE YIELDS OF LIGHT FRAGMENTS IN U235 THERMAL NEUTRON FISSION

1962 ◽  
Vol 40 (8) ◽  
pp. 1017-1026 ◽  
Author(s):  
H. Farrar ◽  
H. R. Fickel ◽  
R. H. Tomlinson
Keyword(s):  
Thermal Neutron ◽  
Yield Curve ◽  
Mass Spectrometric Study ◽  
Detailed Examination ◽  
Mass Region ◽  
Mass Yield ◽  
Neutron Fission ◽  
Molybdenum Isotopes ◽  
Thermal Neutron Fission ◽  
Fission Yields

A mass spectrometric study of the relative yields of the strontium, yttrium, zirconium, and molybdenum isotopes formed in the thermal neutron fission of U235 has made possible a detailed examination of structure of the light mass region of the mass–yield curve. The relative yields of this work have been normalized to 5.77% for Sr90, and when literature and extrapolated values are taken for the remaining chains, the fission yields total 100.8%.

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