scholarly journals Relative Yields of Stable Tellurium Isotopes in Neutron-induced Fission

1982 ◽  
Vol 35 (4) ◽  
pp. 385 ◽  
Author(s):  
JR de Laeter ◽  
KJR Rosman ◽  
JW Boldeman
Keyword(s):  
Mass Spectrometry ◽  
Yield Curve ◽  
Mass Range ◽  
Neutron Fission ◽  
Significant Depression ◽  
Isotopic Abundances ◽  
Thermal Neutron Fission ◽  
First Time ◽  
Fission Yields ◽  
Good Agreement

The relative isotopic abundances of four isotopes of tellurium (125, 126, 128 and 130) produced in the thermal neutron fission of 233U and 23SU have been measured for the first time by solid source mass spectrometry. Samples of 233U and 23SU were irradiated in a reactor and chemically separated by ion exchange techniques to permit nanogram-sized samples of fission product tellurium to be analysed mass spectrometrically. The results for 23SU are in good agreement with published radiometric values, whereas our results for 233U are the first experimental measurements in this mass range. The cumulative fission yields determined by mass spectrometry for ruthenium, palladium, cadmium, tin and tellurium show a smooth mass distribution in the symmetric region for both 233U and 235U, except for a significant depression in the yield curve in the range 111-14.

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.

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.

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%.

Cumulative Yields of the Heavy Fragments in the Fast Neutron Fission of 238U

1972 ◽  
Vol 50 (24) ◽  
pp. 3100-3110 ◽  
Author(s):  
C. K. Mathews ◽  
R. H. Tomlinson
Keyword(s):  
Isotope Dilution ◽  
Mass Range ◽  
Mass Region ◽  
Mass Spectrometric ◽  
Spectrometric Method ◽  
Mass Spectrometric Method ◽  
Neutron Fission ◽  
Fission Spectrum ◽  
Isotopic Abundances ◽  
Fission Yields

Isotopic abundances of the elements xenon, cesium, barium, cerium, neodymium, and samarium formed in the fast (fission spectrum) neutron fission of 238U have been measured using the mass spectrometric method. These ratios were normalized with respect to each other through isobaric nuclides and isotope dilution to obtain the relative yields of isobaric chains in the heavy mass region. By normalizing the heavy mass yields to 100%, the absolute fission yields of 20 chains in the 130–154 mass range were determined.

THE FISSION YIELDS OF THE STABLE AND LONG-LIVED ISOTOPES OF XENON, CESIUM, AND KRYPTON IN NEUTRON FISSION OF U233

1954 ◽  
Vol 32 (8) ◽  
pp. 522-529 ◽  
Author(s):  
W. Fleming ◽  
R. H. Tomlinson ◽  
H. G. Thode
Keyword(s):  
Fine Structure ◽  
Mass Spectrometer ◽  
Yield Curve ◽  
Closed Shell ◽  
Mass Range ◽  
The Other ◽  
Mass Yield ◽  
Fission Yield ◽  
Neutron Fission ◽  
Fission Yields

The fission yields of Xe131, Xe132, Xe134, Xe136, Cs133, Cs135, Cs137, Kr83, Kr84, 10.27 year Kr85, and Kr86 in the neutron fission of U233 have been determined by mass spectrometer methods. The very pronounced fine structure in the mass yield curve in the mass range 131 to 137 found in U235 fission does not occur in the fission of U233. This disappearance of fine structure would not have been predicted by any of the mechanisms which have been suggested to explain the fine structure in U235 fission. The fission yield of the 10.27 year isomer of Kr85 relative to the other krypton isotopes is considerably higher in U233 fission than in U235 fission, indicating some fine structure in this mass range which may be related to the closed shell of 50 neutrons.

THE FISSION YIELDS OF ISOTOPES OF XENON AND KRYPTON IN THE NEUTRON FISSION OF U236 AND U238

1955 ◽  
Vol 33 (9) ◽  
pp. 541-554 ◽  
Author(s):  
R. K. Wanless ◽  
H. G. Thode
Keyword(s):  
Fine Structure ◽  
Fast Reactor ◽  
Yield Curve ◽  
Percentage Change ◽  
Fission Yield ◽  
Los Alamos ◽  
Neutron Fission ◽  
Isotopic Abundances ◽  
Fission Yields

Several uranium samples have been irradiated under various conditions in the Chalk River N.R.X. reactor and in the Los Alamos fast reactor. The fission gases, xenon and krypton, have been extracted from the irradiated material and the relative isotopic abundances determined mass spectrometrically. Fine structure in the mass – fission yield curve has been found in both the xenon and krypton mass ranges for U235 + n and U238 + n fission. It is observed that this fine structure shifts to lower masses, as predicted, for neutron fission of U238. The proportions of U235 and U238 fission that have occurred in the irradiated samples have been estimated from the percentage change in fine structure.

scholarly journals Building the Radiocarbon Chronology for the Archaeological Site Ufa-II, Bashkortostan, Russia: Is this the Elusive “Bashkort” of Medieval Sources?

Radiocarbon ◽  
2013 ◽  
Vol 55 (3) ◽  
pp. 1278-1285
Author(s):  
Vladimir A Levchenko ◽  
Flarit A Sungatov
Keyword(s):  
Mass Spectrometry ◽  
Accelerator Mass Spectrometry ◽  
Archaeological Site ◽  
Radiocarbon Dates ◽  
Site Occupation ◽  
Radiocarbon Chronology ◽  
First Time ◽  
Good Agreement

A suite of accelerator mass spectrometry (AMS) radiocarbon dates for the Ufa-II archaeological site in Bashkortostan, Russia, is obtained for the first time. Dating was done on charcoal samples from a sequence of cultural deposits collected during the 2011 digging season. An age-depth chronology is established using the Bayesian deposition General Outlier P_Sequence model. The oldest age for the site at the horizon immediately over the sterile ground was cal AD 137–237 (68% probability), corresponding to the beginning of site occupation. The youngest 14C date found was late 6th to early 7th century cal AD for the extensive planked boardwalks unearthed at the site. The 14C dates are in good agreement with archaeological determinations based on discovered artifacts.

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