Absolute exp 239 Pu thermal fission yields are given for the stable and long-lived isotopes of krypton, rubidium, strontium, zirconium, xenon, cesium, barium, cerium, neodymium, and samarium. The principal measurement technique for the fission product iso...
National Technical Information Service (NTIS)
Absolute exp 235 U thermal fission yields are given for the stable and long-lived isotopes of krypton, rubidium, strontium, zirconium, molybdenum, ruthenium, xenon, cesium, barium, lanthanum, cerium, neodymium, and samarium. The principal measurement tech...
Fission-track registration characteristics of Lexan plastic track detector immersed in aqueous solution of uranyl nitrate have been studied. An attempt has been made to measure absolute fission yields of some fission products in the 14 MeV induced fission of 238U using ...
NASA Astrophysics Data System (ADS)
Absolute fission yield data are presented for exp 237 Np irradiated in EBR-II. The measurement technique was isotope dilution mass spectrometry. This is believed to be the first published set of comprehensive exp 237 Np yield data based on mass spectromet...
Absolutely calibrated measurements of the neutron yield are important for the evaluation of the plasma performance such as the fusion gain Q in DD operating tokamaks. Total neutron yield is measured with (sup 235)U and (sup 238)U fission chambers and (sup...
Absolute /sup 239/Pu thermal fission yields are given for the stable and long-lived isotopes of krypton, rubidium, strontium, zirconium, xenon, cesium, barium, cerium, neodymium, and samarium. The principal measurement technique for the fission product isotopes was isotope dilution mass spectrometry. The number of ...
Energy Citations Database
Using isotope dilution techniques and mass spectrometry, absolute yields of the Xe and Kr isotopes in the neutron-induced fission of Pu/sup 239/ were determined. Nine of these yields lead to cumulative yields of the respective mass chains 131, 132, 134, 136, 83, 84, 85, 86, and two give ...
The fission product chains resulting from thermal neutron fission of exp 235 U are given as compiled from the latest tabulated data. Included are the calculated absolute cumulative yields, single particle model states for protons and neutrons and experime...
We have measured the mass-yield distribution from the fission of 240Pu induced by fast neutrons from a plutonium metal critical assembly. Measurements were made for 44 fission products from 72Zn to 169Er, from which we calculated total chain yields for 36 mass numbers and constructed a ...
Strontium-90 and yttrium-90 are two of the important fission products. At present they are applied widely in industry because their half life is longer and their fission yield is higher. The radioactivity of the nuclide is of concern, because strontium-90...
For the fission of 241Am induced by fast neutrons from a 239Pu critical assembly, we have determined the mass-yield distribution and measured independent fission yields and one isomer ratio. The mass-yield distribution curve was constructed from the results for 29 total chain ...
We have measured the mass-yield distribution from the fission of /sup 240/Pu induced by fast neutrons from a plutonium metal critical assembly. Measurements were made for 44 fission products from /sup 72/Zn to /sup 169/Er, from which we calculated total chain yields for 36 mass numbers and constructed a ...
The mass-yield distribution for the neutron-induced fission of /sup 238/U by degraded fission spectrum neutrons with an average energy of 1.52 MeV has been measured radiochemically for 26 mass chains in the region A = 89 to 153. Germanium-lithium gamma-ray spectroscopy coupled with beta-particle counting techniques was used to ...
Radiochemically determined mass-yield curves are given for the fission of U/sup 235/ and U/sup 238/ by l4.7-Mev neutrons. Symmetric and to a less extent, very asymmetric modes of fission are more probable at that energy than in thermal fission. Yields of four ...
DOE Information Bridge
Half-lives and yields in photonuclear reactions have been measured for shape isomers in U and Pu isotopes by pulsed-beam techniques bombarding 235,238U and 239,240,242Pu targets with brems-strahlung. Isomeric fission cross sections have been deduced from the measured isomeric to prompt yield ratios within an evaporation model using ...
... Title : ESTIMATES OF FISSION PRODUCT YIELDS OF A THERMONUCLEAR EXPLOSION. ... independent yields of the U238 fission products from a ...
DTIC Science & Technology
Absolute fast reactor fission yield data are presented for exp 240 Pu and exp 242 Pu irradiated in EBR-II. The measurement technique was isotope dilution mass spectrometry for over 40 mass numbers. (ERA citation 04:052318)
The absolute abundances of the isotopes of fissionproduct xenon and krypton in six uranium minerals were determined mass spectrometrically using the isotope dilution technique. The fission products were resolved into a U/sup 238/ spontaneous fission component, a U/sup 235 neutron-induced fission component, ...
An absolute calibration technique for a spontaneously fissioning nuclide (which involves no arbitrary parameters) allows unique determination of the detector efficiency for that nuclide, hence of the fission source strength.
Absolute yields have been determined for 105 gamma rays emitted in the decay of 95 fission products representing 54 mass chains created during thermal-neutron fission of 245Cm. These results include 17 mass chains for which no prior yield data exist. Using a Ge(Li) detector, spectra were ...
The flssion of natural thorium by helium ions with energies from 20 to 40 Mev was studied using radiochemical determination of the absolute yields of several fission products. A small symmetric peak was observed in the valley of the generally asymmetric mass-yield curve, and evidence for fine structure was ...
Absolute yields have been determined for 47 gamma rays emitted in the decay of 37 fission products representing 25 mass chains created during thermal-neutron fission of 229Th. Using a Ge(Li) detector, spectra were obtained of gamma rays emitted between 15 min and 0.4 yr after very short irradiations by thermal ...
Absolute yields have been determined for 107 gamma rays emitted in the decay of 97 fission products representing 54 mass chains created during thermal-neutron fission of 249Cf. These results include 14 mass chains for which no prior yield data exist. Using a Ge(Li) detector, spectra were ...
An analytical program to determine absolute fast reactor fission yields for exp 233 U, exp 235 U, exp 238 U, exp 237 Np, exp 239 Pu, exp 240 Pu, exp 241 Pu and exp 242 Pu has been completed. Details of sample preparation, dissolution and separation for an...
Neutron yields were determined by measuring the activities produced in the INEL manganese bath. Of the three fission methods used, the neutron-fission coincidence method was found to be the most consistent and reliable. The value of /sup 252/Cf anti ..nu.. obtained by these measurements was 3.764. (RWR)
Absolute cumulative yields have been determined for 49 fission products representing 36 mass chains created during thermal-neutron fission of /sup 239/Pu, including 3 mass chains for which no prior data exist. Using Ge(Li) spectroscopy, spectra were obtained of gamma rays from decay of fission ...
The authors propose an algorithms for calculating the absolute yield of delayed neutrons--both the total emission and the discrete groups--using the simplest methods based on the application of systematics and of the semiempirical formulas of the five-Gaussian fission product mass distribution. Within the framework of their statistical ...
The mass-yield curve for the fission of Np/sup 237/ by 14.5 Mev neutrons was determined. An absolute yield of 4.94% for Mo/sup 99/ was measured and used to normalize the massyield curve. The shape of the curve is very similar to the U/sup 235/ and U/sup 238/ fission-yield curves with ...
By irradiating targets of highly enriched U/sup 235/ with 14.7 Mev neutrons produced by the D,T reaction in the Aldermaston Cockcroft-Walton accelerator, the fission Ga/sup 73/, Zn/sup 72/, and Ni/sup 66/ were determined relative to that of Mo/sup 99/. A determination of the absolute fission yield of ...
Photo-fission has been proposed for production of neutron-rich radioactive isotopes because potentially attractive absolute fission yields may be achieved with a modest-cost electron accelerator, and because the relative production of the most neutron-rich isotopes should be substantially enhanced in ...
Absolute fast reactor fission yields are presented for over 40 stable and long-lived isotopes of Kr, Rb, Sr, Zr, Mo, Ru, Sb, Xe, Cs, Ba, La, Ce, Nd, and Sm for /sup 233/U, /sup 235/U, /sup 238/U, and /sup 239/Pu irradiated in EBR-II. A method for ordering fission yields as a function of neutron ...
BS>The status of delayed neutron measurements is reviewed. Emphasis is placed on the absolute yield va the energy of the neutrons cauging fission, group yields and periods, and in the delayed neutron spectra. Systematics are discussed; and an evaluated data set, based both on available measurements and ...
Fission yield measurement and yield compilation activities in the major laboratories of the world are reviewed. In addition to a general review of the effort of each laboratory, a brief summary of yield measurement activities by fissioning nuclide is presented. A new fast reactor ...
A prototype fission chamber was tested and several chambers were built. The design and performance characteristics are presented. (FS)
... Descriptors : *Fission, *Fission products, *Coincidence counting, Uranium, Plutonium, X rays, Gamma rays, Spectrum analyzers, Curve fitting ...
Delayed neutrons are emitted by excited nuclei formed in beta decay of fission products called delayed neutron precursors. About 1% of the total neutrons released in fission are delayed neutrons; however, this small fraction plays an important role in nuclear reactor control. The delayed neutrons determine the time-dependent behavior of reactors, and ...
A summary of the work done to date in connection with fission yield measurements and fission related studies is given. During the past three years, research aimed at the ultimate extraction of isotopic fission yields from neutron induced fission of 233, 2...
The apparent fission yield of the rare gas fission products from four mass chains is calculated as a function of separation time for six different fissioning systems. A plot of the calculated fission yield along with a one standard deviation error band is...
... 99. With this ratio and pertinent data from the thermal neutron fission of U-235, the mass chain yield was calculated. The ...
... Accession Number : AD0762746. Title : Fission Yield Determinations. Descriptive Note : Semi-annual rept.,. Corporate Author ...
The absolute yields of prompt and delayed fissions induced by negative muons stopping in ('235)U and ('238)U have been measured using multiplate fission chambers. A coincidence with the muonic uranium K(,(alpha)) X rays was used to identify the muon stops that both stopped in the target and reached the muonic K ...
The part of the FFTF Reactor Characterization Program reported in this paper is a measurement of absolute fission rates of eight major fuel isotopes at two different positions within the reactor. The instruments employed in these tests were fission ioniza...
The procedures and status of the absolute measurement of the neutron capture cross sections for exp 115 In and exp 232 Th are described. Work on the exp 239 Pu fission fragment anisotropy and absolute measurement of the fast neutron fission cross section ...
A method to evaluate fission yields in experiments of induced and spontaneous fission which use fissionable target materials in the configuration of contact with dielectric track detectors has been developed. The effect of energy absorption of the fission...
... the photon yields in the ... Descriptors : *CHEMICAL REACTIONS, *PHOTONS, *CHEMILUMINESCENCE ... LASERS, FLUORINE, YIELD, NITROGEN ...
Fission-product yields relative to the fission yield of Mo99 were measured for the fission of Th232 with He4 ions of energies ranging from threshold to 45 MeV and for the fission of U235 with 14-MeV neutrons. The linear relationships between fission ...
A new and improved correction for accidental coincidences has been devised. Comparison of results based on earlier formulations are provided. The differences between the new expression and the frequently used older formulations indicate possible systematically significant discrepancies in some reported experiments, for example, absolute determinations of the neutron ...
... Title : THE ABSOLUTE QUANTUM YIELD DUE TO THE INTERNAL PHOTOELECTRIC EFFECT IN CHEMICALLY-DEPOSITED PbS FILMS,. ...
A method for the experimental determination of the capture-to-fission ratio (alpha) in low-flux reactors is outlined. The procedure utilizes pile oscillator techniques but does not require an absolute determination of either the reactivity or the reactor power. A spontaneous fission source is used to establish the importance ...
The topics covered is this paper are:- (a) cumulative yields in thermal neutron fission and in fast fission up to 14 MeV incident neutron energy; (b) dependence of the yields on incident neutron energy and spectrum; (c) independent yields; (d) charge disp...
The neutron-induced fission cross section of Np/sup 237/ was measured as a function of neutron energy in the range 0.9 to 8.0 Mev. Measurements above 1.7 Mev were made relative to the fission cross section of U/sup 238/ using 2 pi / sup -/ counting of fission fragmnents from thin fissile deposits placed back to back in a ...
On the basis of up-to-date evaluated data on the fission products yields, numbers of secondary fission neutrons and beta decay energies of the fission products, the fission energy E of a number of uranium and transuranium isotopes and the total energy rel...
Six new fission yields were measured on the wings of the Cf/sup 252/ spontaneous fission curve. The width of the peaks at half maximum height is found to be 13 plus or minus 1 mass units. (auth)
A method is described for calculating the independent yields of fission products on the basis of the quantitative characteristics of the fast-neutron emission. The formulation and solution of the inverse problem are discussed for fission by neutrons at �14.5 MeV.
As part of a study of nuclear charge distribution in the region of symmetric fission, the existence and cumulative fission yield of 117Pd were sought. Palladium was isolated free from silver and cadmium at different times after fission and the quantity of...
The configuration of the contact of fissionable target materials with dielectric track detectors is reviewed to obtain fission yields corrected for fragment self-absorption in fission sources of different thicknesses and for optical magnification for the ...
... Title : Fission Product Yields from 6-9 MeV ... Descriptors : *URANIUM, *RADIOACTIVE ISOTOPES, *FISSION PRODUCTS, *NEUTRON IRRADIATION ...
The nuclear model code TALYS has been extended to enable the prediction of fission yields. The mass yield curves are extracted from temperature-dependent multi-modal random-neck rupture calculations. Charge yields of the fission fragment are determined using the scission-point model and ...
... FISSION, FISSION PRODUCT ACTIVITY, NUCLEAR ISOBARS, NEUTRON REACTIONS, THERMAL NEUTRONS, RADIOACTIVE ISOTOPES ...
... Descriptors : (*FISSION PRODUCTS, URANIUM), (*IODINE, RADIOACTIVE DECAY), (*TELLURIUM, RADIOACTIVE DECAY), DECAY SCHEMES ...
Published radiochemical measurements of yields from the fast fission of U-238 are reviewed, and a complete set of yields between masses 77 and 161 is recommended for use in fission product poisoning calculations. The pseudofission- product treatment is adopted to simplify presentation and handling of the ...
The absolute fission yields of 46 fission products in {sup 238}U (99.9997 at.%), 46 fission products in {sup 237}Np, 27 fission products in {sup 238}Pu (99.21 at.%), 30 fission products in {sup 240}Pu (99.48 at.%), 30 fission ...
The operating conditions of a neutron diagnostic systems which are responsible for measuring of the total neutron yield in the ITER tokamak reactor are analyzed. Based on results of neutronic calculations and analysis of suitable methods for measuring the neutron yield, a concept of a system for neutron flux measurement in the divertor is proposed. The ...
... Comparison of the Absolute Quantum Yields of the ... from the O/NO gas phase reaction ... and the luminol chemiluminescence quantum yield lead to ...
During the initial deuterium-tritium experiments on TFTR, neutron emission was measured with {sup 235}U and {sup 238}U fission chambers, silicon surface barrier diodes, spatially collimated {sup 4}He proportional counters and ZnS scintillators, and a variety of elemental activation foils. The activation foils, {sup 4}He counters and silicon diodes can discriminate between 14 ...
The overall objective has been to measure the independent and cumulative fission yields of selected halogen and rare gas nuclides for application to characterization of underground nuclear detonations. The studies have included fission yield measurements ...
A simple one-parameter model is presented for calculating the distribution of independent yield strength between ground and isomeric states of primary fission products formed by neutron-induced fission of actinide nuclei. Yield branching ratios are calcul...
It has been suggested that the effect of changing excitation energy on the shape of the fission product mass-yield curve from fission of a single nuclear species is due to the change in the relative amounts of two energy-independent modes of fission, each giving rise to its own characteristic ...
A method of absolute nuclear material assay of an unknown source comprising counting neutrons from the unknown source and providing an absolute nuclear material assay utilizing a model to optimally compare to the measured count distributions. In one embodiment, the step of providing an absolute nuclear material assay comprises ...
... Abstract : The half lives and yields of the photoneutrons created in heavy water by U(235) fission product gamma rays have been measured. ...
... Accession Number : AD0663565. Title : CUMULATIVE FISSION YIELD AND HALF-LIFE OF 134SB,. Corporate Author : NAVAL ...
Absolute (n, gamma ) cross-sections of some fission products with high yield have been measured. In addition, Fe has been studied to remove some unexplained discrepancies in earlier crosssection measurements. Both the gamma and the neutron detector have been calibrated absolutely, so the values derived ...
The delayed neutrons from neutron-induced fission in /sup 232/U, /sup 237/Np, /sup 238/Pu, /sup 241/Am, /sup 242/Am/sup m/, /sup 245/Cm, and /sup 249/Cf were studied for the first time; those from /sup 232/Th, /sup 233/U, /sup 235/U, /sup 238/U, /sup 239/Pu, /sup 241/Pu, and /sup 242/Pu were measured again. The data were used to develop an expression for the prediction of the ...
The features of ENDF/B-V with respect to fission yields are described. Yields for approximately 1100 nuclides are given for each of 11 fissioning nuclides at one or more fission-neutron energies, plus the yield uncertainties. Selected chain yields and ...
Chain yields and independent yields of the U/sup 238/ fission products from a thermonuclear explosion were estimated. Since unclassified data for this kind of process are scanty, some features of the mass yield curve were inferred from published data on U/sup 238/ fission by neutrons ...
In keeping with the statement of work, I have examined the fission product yields of 60 fissioning reactions. In co-authorship with the UTR (University Technical Representative) Talmadge R. England ``Evaluation and Compilation of Fission Product Yields 1993,`` LA-UR-94-3106(ENDF-349) October, ...
The absolute measurement of neutron emission rate from the whole plasma is a very important diagnostics as a fusion power monitor in fusion experimental devices with D-T or D-T operations. Here measurement techniques of time-resolved and time-integrated absolute neutron emission on the present tokamaks and ITER are reviewed. In the present tokamaks, ...
On the basis of measured yields for 72 gamma rays and known nuclear data, cumulative fission-product yields were deduced for 69 fission products having half-lives between 36 seconds and 65 days representing 41 mass chains created during thermal-neutron fission of 243Cm.
The fission product Ba/sup 140/ is often used as a standard in fission yield determinations. A method is presented for this determination from the thermal neutron fission of U/sup 235/ The fission yield of Ba/sup 140/ was found by this method to be 6,36 plus or ...
For the reactor neutron induced fission of exp 241 Am the fission yields for a total of 35 masses were determined as against exp 235 U fission yields and compared with available data. The shape of the mass distribution curve was well defined by the measur...
The absolute neutron yield of the 14 MeV Frascati neutron generator (FNG) is routinely measured by means of the associated alpha-particle method with a silicon surface barrier detector (SSD). This paper describes the work carried out to characterize the neutron source in terms of absolute intensity and angle-energy distribution of the ...
The fission distribution of fission of thorium with alpha particle of average energy 37.5 Mev has been measured by the chemical method. The distribution found shows that the characteristic dip in the fission yield mass spectrum has been raised to within a factor of two of the peaks compared to a factor of 600 in ...
The distribution of mass in the spontaneous fission of Pu/sup 240/ was investigated radiochemically by measuring the fission yields of fifteen isotopes in the mass range 89 to 147. Comparisons are made with other published work on spontaneous flssion to reveal trends in the yield-mass relationship with ...
Proton even-odd staggering in fission fragment yields and its relation with energy dissipated in the fission process are investigated with respect to symmetric and asymmetric charge splits. Thermal-neutron and electromagnetic induced fission provide different fissioning systems in a range of ...
In this paper, first we summarize the current status of the US evaluation for 34 fissioning nuclides at one or more neutron incident energies and for spontaneous fission. Currently there are 50 yields sets, and for each we have independent and cumulative ...
In this paper we summarize the current status of the recent US evaluation for 34 fissioning nuclides at one or more neutron incident energies and for spontaneous fission. Currently there are 50 yields sets, and for each we have independent and cumulative ...
To assist in the improvement of fission product yield data libraries, the statistical theory of fission was investigated. Calculation of the theory employs a recent nuclear mass formula and nuclear density of states expression. Yields computed with a simp...
The equal charge displacement rule is used for estimating yields of some important fission products. The present method increases the reliability of previous estimates. Using recent yield values, thermal and resonsnce effects of gross fission products are calculated. (auth)
Studies of fission-product gamma emanation shortly after fission (1 to 100 sec) have been initiated. The half-lives that will be established in this program, when used in conjunction with initial yields, will provide the fission-product yield history for ...
... Report Date : 23 AUG 1972. Pagination or Media Count : 28. Abstract : Absolute electron yields from tantalum, molybdenum, copper and aluminum ...
The use of lanthanum as a common carrier for all lanthanides was studied. The results show that lanthanum under the given conditions carries trace lanthanum and lanthanides to the same extent. On this basis a radiochemical method for the determination of nuclear reaction yields was developed. Lanthanum is used as carrier in fluoride and hydroxide precipitations for ...
The fission chains are discussed. The methods for the determination of independent and cumulative fission yields are described. Cumulative yields in low-energy fission were compnnled and the resulting mass-yield curves are given. Mass distributions from ...
... and mass yield data for U236 fission are presented ... the surface tension parameters of the fragments and kinetic energies of the fragment pairs ...
... Title : SENSITIVITY ANALYSIS OF THE RADIAL DISTRIBUTION MODEL. SENSITIVITY TO CARRIER MATERIAL, YIELD AND TYPE OF FISSION,. ...
Separate abstracts were prepared for the 29 papers presented. Workshop reports on decay heat, fission yields, beta- and gamma-ray spectroscopy, and delayed neutrons are included. An appendix contains a survey of the most recent compilations and evaluations containing fission product yield, ...
The ENDF/B-5 Fission Product Yields File contains a complete set of independent and cumulative fission product yields, representing the final data from ENDF/B-5 as received at the IAEA Nuclear Data Section in June 1985. Yields for 11 fissioning nuclides a...
High resolution measurements of prompt ?-rays emitted from fission fragments accompanied by light charged particles (LCP) and those emitted from normal binary fission fragments in 252Cf fission were simultaneously carried out using a 30 cm3 Ge(Li) detector. A ``sandwich'' type of arrangement in the source-detector assembly was used to ...
Of the many available models that describe fission yields, the one proposed by R. Waldo seems to best reproduce the total delayed neutron yeilds obtained in fission by thermal or fission spectrum neutrons. A computer code was written to calculate fission product yields and ...
Measurements in AFSR of the changes in some fission ratios which result from the proximity of relatively small quantities of steel and polyethylene are described. The results show that some of the measurements with the Kirn absolute fission chambers in ZPR III are probably in error by several percent. (auth)
We have measured absolute cross sections for (p,xn) reactions (x ranges from 0 to 8) from /sup 238/U, /sup 235/U, and /sup 232/Th targets irradiated with 200-MeV protons at the Brookhaven AGS Linac injector. Chemical yields were determined by using /sup 239/Np and /sup 233/Pa as tracers. Yield patterns obtained in this work can be ...
The United States and the United Kingdom have been engaged in a joint research program in which samples of fissile and fertile actinides have been incorporated into three separate fuel pins and irradiated in the Dounreay Prototype Fast Reactor in Scotland. The actinides in the second fuel pin were studied for fission-product decay, specifically to obtain ...
The yields of 27 mass chains in the fission of $sup 235$U and the ratio of fast-neutron to thermal-neutron fission yields of 21 mass chains in the fission of $sup 239$Pu induced by fast neutrons (median energy approximately 180 keV) have been measured in the reactor PROTEUS. The ...
The first in a series of quarterly progress reports on ERDA budgeted activities subcontracted to Allied Chemical Corporation at the Idaho National Engineering Laboratory is presented. The work is performed by the Technical Division and is divided into three subjects. Fuel cycle research and development includes fluidized-bed calcination and post treatment of commercial nuclear fuel process waste; ...
It is proposed to use transfer-induced fission in inverse kinematics coupled to the large acceptance spectrometer VAMOS to identify in atomic and mass number the complete distribution of the fission fragments. The measure of the kinetic properties of the transfer partner allows for determining precisely the excitation of the fissioning ...
Cumulative fission yield of 148 cesium isotopes and some other fission products produced by thermal-neutron fission of 235 uranium is determined by Germanium/Lithium spectroscopic methods. The measuremets were done at Tsing-Hua open pool reactor using 3 t...
Information concerning input is given first. Then formulas are given for calculation of atoms/millimeter, fissions, kiloton yield, R-value, atoms/fission, fissions/fission, bomb fraction, fissions/atoms, atoms, atoms/atoms, fissions/atoms, atom ratio, total atoms formed, ...
Information concerning input is given first. Then formulas are given for calculation of atoms/millimeter, fissions, kiloton yield, R-value, atoms/fission, fissions/fission, bomb fraction, fissions/atoms, atoms, atoms/atoms, fissions/atoms, atom ratio, tot...
This report is a summary of the current status of an ongoing investigation of the influence of the pairing force in the distribution of independent yields. At this time pairing systematics have been obtained for exp 235 U thermal and fast fission yields b...