DIFFUSION PHENOMENA AND ISOTOPE EFFECTS IN THE EXTRACTION OF FISSION-PRODUCT XENON AND KRYPTON FROM IRRADIATED U3O8

1960 ◽  
Vol 38 (7) ◽  
pp. 945-954 ◽  
Author(s):  
T. J. Kennett ◽  
H. G. Thode
Keyword(s):  
Activation Energy ◽  
Fission Product ◽  
Isotope Effects ◽  
Isotopic Fractionation ◽  
Low Energy ◽  
Energy Of Activation ◽  
Diffusion Phenomena ◽  
Fission Yields

An investigation of the diffusion of fission-product xenon and krypton from irradiated U3O8 powder as a function of temperature has revealed isotopic fractionation and also a double-valued activation energy. The apparent fission yields of Xe131 and Xe132 show abnormal enrichments of up to a factor of 10. These enrichments appear to be related to the precursor half-lives of xenon. When isotopic fractionation exists, the diffusion results exhibit an extremely low energy of activation.

scholarly journals Separation of Lanthanide Isotopes from Mixed Fission Product Samples

Separations ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 104
Author(s):  
Leah M. Arrigo ◽  
Jun Jiang ◽  
Zachary S. Finch ◽  
James M. Bowen ◽  
Staci M. Herman ◽  
...  
Keyword(s):  
Fission Product ◽  
Fission Products ◽  
Nuclear Data ◽  
Product Analysis ◽  
Data Production ◽  
Thermal Irradiation ◽  
Nuclear Events ◽  
Lanthanide Separation ◽  
Enriched Uranium ◽  
Fission Yields

The measurement of radioactive fission products from nuclear events has important implications for nuclear data production, environmental monitoring, and nuclear forensics. In a previous paper, the authors reported the optimization of an intra-group lanthanide separation using LN extraction resin from Eichrom Technologies®, Inc. and a nitric acid gradient. In this work, the method was demonstrated for the separation and quantification of multiple short-lived fission product lanthanide isotopes from a fission product sample produced from the thermal irradiation of highly enriched uranium. The separations were performed in parallel in quadruplicate with reproducible results and high decontamination factors for 153Sm, 156Eu, and 161Tb. Based on the results obtained here, the fission yields for 144Ce, 153Sm, 156Eu, and 161Tb are consistent with published fission yields. This work demonstrates the effectiveness of the separations for the intended application of short-lived lanthanide fission product analysis requiring high decontamination factors.

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

1983 ◽  
Vol 61 (11) ◽  
pp. 1490-1497 ◽  
Author(s):  
K. J. R. Rosman ◽  
J. R. De Laeter ◽  
J. W. Boldeman ◽  
H. G. Thode
Keyword(s):  
Stable Isotopes ◽  
Fine Structure ◽  
Fission Product ◽  
Mass Spectrometer ◽  
Smooth Curve ◽  
Mass Region ◽  
Neutron Fission ◽  
Source Mass ◽  
Induced Fission ◽  
Fission Yields

The relative cumulative fission yields of the six stable isotopes of tin (117Sn,118Sn, 119Sn, 120Sn, 122Sn, and 124Sn) and the long-lived isotope 126Sn have been measured in the thermal and epicadium neutron fission of 233U and 235U, and the epicadium neutron fission of 238U. Nanogram-sized fission product tin samples were extracted from irradiated uranium samples and analyzed in a solid source mass spectrometer. In each case a smooth curve can be drawn through the yield points of the seven isotopes of tin. There is, therefore, no evidence of "fine structure" in the 117 ≤ A ≤ 126 portion of the symmetric mass region.

scholarly journals Isotopic fractionation in low-energy ion implantation

1997 ◽  
Vol 102 (E8) ◽  
pp. 19335-19343 ◽  
Author(s):  
K. V. Ponganis ◽  
T. Graf ◽  
K. Marti
Keyword(s):  
Ion Implantation ◽  
Isotopic Fractionation ◽  
Low Energy

Thermal Degradation of Complexes Derived from Cu (II) Groundnut (Arachis hypogaea) and Sesame (Sesamum indicum) Soaps

2018 ◽  
Vol 0 (0) ◽  
Author(s):  
Anju Joram ◽  
Rashmi Sharma ◽  
Arun kumar Sharma
Keyword(s):  
Activation Energy ◽  
Fatty Acid ◽  
Thermal Degradation ◽  
Arachis Hypogaea ◽  
Edible Oils ◽  
Analytical Data ◽  
Spectroscopic Technique ◽  
Sesamum Indicum ◽  
Energy Of Activation ◽  
Significant Information

Abstract The complexes have been synthesized from Cu (II) soaps of groundnut (Arachis hypogaea) and sesame (Sesamum indicum) oils, with ligand containing nitrogen and sulfur atoms like 2-amino-6-methyl benzothiazole. The complexes were greenish brown in color. In order to study TGA, first characterized them by elemental analysis, and spectroscopic technique such as IR, NMR and ESR. From the analytical data, the stoichiometry’s of the complexes have been observed to be 1:1 (metal:ligand). These complexes have been thermally analyzed using TGA techniques to determine their energy of activation. These complexes show three step thermal degradation corresponding to fatty acid components of the edible oils and each complex has three decomposition steps in the range of 439–738 K. Various equations like Coats–Redfern (CR), Horowitz–Metzger (HM) and Broido equations (BE) were applied to evaluate the energy of activation. The values of energy of activation are observed to be in the following order for both copper groundnut benzothiazole (CGB) and copper sesame benzothiazole (CSeB) complexes: CGB > CSeB. CGB is observed to be more stable than CSeB due to its higher activation energy. The above studies would provide significant information regarding the applications of synthesized agrochemicals and their safe removal through parameters obtained in degradation curves and its relation with energy.

scholarly journals Fission Product Yield Measurements from Neutron-Induced Fission of 235,238 U and 239Pu

2020 ◽  
Vol 232 ◽  
pp. 03006
Author(s):  
M. A. Stoyer ◽  
A. P. Tonchev ◽  
J. A. Silano ◽  
M. E. Gooden ◽  
J. B. Wilhelmy ◽  
...  
Keyword(s):  
Fission Product ◽  
Nuclear Physics ◽  
Fission Products ◽  
Product Yield ◽  
Tandem Accelerator ◽  
Precision Data ◽  
High Precision Data ◽  
Induced Fission ◽  
The Impact ◽  
Fission Yields

Fission product yields (FPY) are one of the most fundamental quantities that can be measured for a fissioning nucleus and are important for basic and applied nuclear physics. Recent measurements using mono-energetic and pulsed neutron beams generated using Triangle Universities Nuclear Laboratory’s tandem accelerator and employing a dual fission chamber setup have produced self-consistent, high-precision data critical for testing fission models for the neutron-induced fission of 235,238U and 239Pu between neutron energies of 0.5 to 15.0 MeV. These data have elucidated a low-energy dependence of FPY for several fission products using irradiations of varying lengths and neutron energies. This paper will discuss new measurements just beginning utilizing a RApid Belt-driven Irradiated Target Transfer System (RABITTS) to measure shorterlived fission products and the time dependence of fission yields, expanding the measurements from cumulative towards independent fission yields. The uniqueness of these FPY data and the impact on the development of fission theory will be discussed.

Faceting in dilute oxygen atmospheres of group VIA metals

1972 ◽  
Vol 331 (1586) ◽  
pp. 429-443 ◽  
Keyword(s):  
Activation Energy ◽  
Electron Diffraction ◽  
Smooth Surface ◽  
High Energy ◽  
Low Energy ◽  
Energy Electron ◽  
High Energy Electron ◽  
Ordered Structures ◽  
Surface Parameters ◽  
Chemisorbed Oxygen

Certain planes of the group VIA metals, Cr, Mo and W, which are stable in ultra high vacua, readily develop facets when heated at low homologous temperatures in oxygen pressures as low as 10 -6 Pa. We have investigated the (100) and (110) surfaces of these metals by both low energy and reflexion mode high-energy electron diffraction. The (100) surfaces of tungsten and molybdenum readily develop facets which are of {110} and {211} type. The faceting is preceded by the formation of various ordered structures characteristic of chemisorbed oxygen. The (100) surface of chromium is stable in oxygen; however, the (110) surface develops {100} facets. No simple ordered structures are observed on the (110) surface of chromium before faceting and the facets soon disappear beneath epitaxially grown oxide. On all three metals the faceting process is reversible. The smooth surface may be regenerated by heating in the absence of oxygen. The activation energy for this process is high. The effect of faceting on surface parameters is discussed with particular reference to the growth of oxide.

A NOTE ON THE ENERGY OF ACTIVATION OF THE AMYLASE IN VARIOUS HUMAN BODY FLUIDS

1956 ◽  
Vol 34 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Leslie Kovacs ◽  
Jules Tuba
Keyword(s):  
Activation Energy ◽  
Human Body ◽  
Mean Value ◽  
Body Fluids ◽  
Normal Serum ◽  
The Body ◽  
Energy Of Activation ◽  
Heat Inactivation ◽  
Head Of The Pancreas ◽  
The Mean

The activation energy was determined for the amylase present in the following fluids obtained from the human body: urine, duodenal fluid, saliva, and normal serum, as well as serum from patients with mumps, acute pancreatitis, and carcinoma of the head of the pancreas. Over a temperature range of 4°–37.4 °C., with starch as a substrate, the value of the energy of activation was similar in all cases to that for bacterial α-amylase, and the mean value was 13,740 ± 200 cal./mole. Partial heat inactivation of the enzyme was evident in some cases at 37.4°. On the basis of the evidence obtained it appears that α-amylase is present in all the body fluids examined.

Sign in / Sign up

Export Citation Format

Share Document