Gamma-ray Spectrometric Technique Research Articles

Independent isomeric yield ratios of fission products in the epi-cadmium neutron induced fission of 233U

The independent isomeric yield ratios (IR) of 128,130,132Sb, 131,133Te, 132,134,136I, 135Xe and 138Cs have been measured in the epi-cadmium neutron induced fission of 233U by using an off-line gamma-ray spectrometric technique. The average neutron energy of the epi-cadmium reactor neutron spectrum is 1.9 MeV. The root mean square fragment angular momenta (JRMS) were deduced from the IR values by using spin dependent statistical model analysis. The IR and JRMS values of considered fission products in the epi-cadmium neutron induced fission of 233U were compared with the literature data in the thermal neutron induced fission of 233U to examine the influence of excitation energy on nuclear structure effect.

Post-Neutron Mass Yield Distribution in the Epi-Cadmium Neutron-Induced Fission of 239Pu

In the epi-cadmium neutron-induced fission of 239Pu, cumulative and independent yields of various fission products within the mass ranges of 83 to 117 and 123 to 156 have been measured by using an off-line gamma-ray spectrometric technique. The spectrum average neutron energy is 1.9 MeV. Charge distribution correction on the cumulative yields was applied to obtain their post-neutron mass yields. Mass yield distribution parameters such as the peak-to-valley (P/V) ratio, the full-width at tenth-maximum of light and heavy mass wings, the average light mass <AL> and heavy mass <AH>, and the average neutron number <ν> were obtained. The mass yields in the epi-cadmium and thermal neutron–induced fission of 239Pu were compared to examine the role of excitation energy on the P/V ratio and the nuclear structure effect.

HR GRS-HPGe as NDT method for quantification of uranium and 235U content in process stream samples from UO2 fuel production facilities

Abstract Uranium concentration and uranium isotopic content are two important and critical parameters for any nuclear fuel fabrication facilities. In the present study emphasis has been given on the usage of high resolution gamma ray spectrometric (HR-GRS) technique with HPGe detector for the determination of uranium and 235U content in uranium process stream samples. The work has been carried out with an aim to give quick analytical feedback to production facility and also to minimize the generation of analytical waste. These are important requirements for any industrial lab with high analytical load attached to production facility. In this paper a simple and a non-destructive testing (NDT) method has been described for quantification of uranium and 235U content in samples received from UO2 fuel production facilities using HR-GRS technique with high purity germanium (HPGe) detector. A 185.7 keV line of 235U has been used for quantification of uranium in process solutions containing 1 g/L to 600 g/L of uranium covering both aqueous and organic process stream solutions. The results have been compared with that of Davies and Gray method. The limitations associated with gamma ray emitted from daughter products of 238U and self-induced or self-excited X-ray fluorescence lines of uranium have also been studied. Multi Group Analysis of Uranium (MGAU) software code has been used for measurement of 235U content in variety of samples. The results obtained are compared with that of results by thermal ionization mass spectrometer (TIMS).

Post-Neutron Mass Yield Distribution in the Epi-Cadmium Neutron-Induced Fission of 233U

Post-neutron mass yield distribution in the epi-cadmium neutron-induced fission of 233U has been carried out by measuring the cumulative yields of various fission products within the mass ranges of 77 to 117 and 123 to 153 using an off-line gamma-ray spectrometric technique. Independent yields of a few fission products were also measured by using the same technique. Charge distribution correction has been applied on cumulative yields to obtain the post-neutron mass yields. The mass yield distribution parameters such as full-width at tenth-maximum of light and heavy mass wings, the average light mass <AL> and heavy mass <AH>, and the average number of neutrons <ν> were obtained. The spectrum average neutron energy is 1.9 MeV. Thus, the role of excitation energy on the nuclear structure effect was examined by comparing the mass yield data in between the epi-cadmium and thermal neutron–induced fission of 233U.

Independent isomeric yield ratios of fission products in the epi-cadmium neutron induced fission of 241Pu

Abstract Independent isomeric yield ratios (IR) of 130,132Sb, 131,133Te, 134,136I, 135Xe and 138Cs have been measured in the epi-cadmium neutron induced fission of 241Pu by using an off-line gamma-ray spectrometric technique. The average neutron energy (&lt;E n&gt;) of the epi-cadmium reactor neutron spectrum is 1.9 MeV. From the IR values, root mean square fragment angular momenta (J RMS) were deduced by using spin dependent statistical model analysis. Effect of nuclear structure on J RMS values was examined. The present data in the epi-cadmium neutron induced fission of 241Pu were compared with the similar data in the thermal neutron induced fission of 241Pu to examine the role of excitation energy on fragment angular momentum.

Measurement of isomeric yield ratios for 104m,gAg and 106m,gAg isotopes using bremsstrahlung end-point energies of 45–75 MeV

In this study, the isomeric yield ratio (IR) values of 104m,gAg and 106m,gAg in an natAg(γ,xn) reaction at the bremsstrahlung end-point energies (Ee) of 45, 50, 55, 60, 70, and 75 MeV were measured using an off-line gamma-ray spectrometric technique. The IR values at different bremsstrahlung end-point energies were also calculated from the cross-section data available in the TENDL-2019 library, and they were found to exhibit a similar trend with some differences in the magnitude. Herein, the IR values of 104m,gAg and 106m,gAg with the bremsstrahlung end-point energies of 70 and 75 MeV were measured for the first time. The present data were compared with those from the literature for 107,109,natAg(γ,xn), natAg(n,xn), natPd(p,xn), and 103Rh(α,xn) reactions to examine the role of the excitation energy and input angular momentum.

Post-Neutron Mass Yield Distribution in the Epi-Cadmium Neutron-Induced Fission of 245Cm

The cumulative and independent yields of various fission products within the mass ranges of 83 to 117 and 123 to 161 have been measured in the epi-cadmium neutron-induced fission of 245Cm by using an off-line gamma-ray spectrometric technique. Charge distribution correction was applied on the cumulative yields to obtain the post-neutron mass yield distribution. From the mass yield distribution data, the full-width at tenth-maximum of light and heavy mass wings, average light mass <AL> and heavy mass <AH>, average neutron number <ν>, and peak-to-valley ratio were obtained for the first time. Comparison of mass yield distributions was made between the epi-cadmium and thermal neutron–induced fission of 245Cm to examine the role of excitation energy on the nuclear structure effect and P/V ratio.

Post-Neutron Mass Yield Distribution in the Epi-Cadmium Neutron-Induced Fission of 229Th

In the epi-cadmium neutron-induced fission of 229Th, cumulative yields of relatively long-lived fission products within the mass range of 77 to 151 were measured by using an off-line gamma-ray spectrometric technique. The mass yields were obtained from the cumulative fission product yields by using charge distribution correction. The peak-to-valley (P/V) ratio, full-width at tenth-maximum of light and heavy mass wings, average light mass <AL> and heavy mass <AH>, and average neutron number <ν> were obtained. The P/V ratio was obtained for the first time and was found to be about three times lower in the epi-cadmium neutron fission than in the thermal neutron fission of 229Th, which shows the role of excitation energy. The fine structure of the mass yield distribution in the 229Th(nf,f) reaction was explained from the viewpoint of nuclear structure effect and the Standard I and Standard II asymmetric modes of fission.

Post-Neutron Mass Yield Distribution in the Thermal Neutron Induced Fission of 233U

In the thermal neutron–induced fission of 233U, the cumulative and independent yields of various fission products within the mass ranges of 77 to 109 and 123 to 155 have been measured by using an off-line gamma-ray spectrometric technique. The lower yields of 86Br and 136I than usual trend indicate the formation of delayed neutron emitters 87Br and 137I. From the cumulative yields, the post-neutron mass yield distribution was obtained after applying the charge distribution correction. The data from the present and earlier work of our laboratory in the 233U(nth,f) reaction were compared with similar data of 232,235U(nth,f) and 238U(n,f) reactions to examine the effect of mass difference of the fissioning systems on the fine structure of the mass yield distribution. The mass yield distribution in the 233U(nth,f) reaction was also compared with those of 229Th(nth,f), 241Pu(nth,f), and 245Cm(nth,f) reactions to examine the effect of charge and mass difference of the fissioning systems and also to examine the different behaviors of standard I and standard II asymmetric modes of fission.

Post-Neutron Mass Yield Distribution in the Thermal Neutron Induced Fission of 235U

The cumulative and independent yields of various fission products within the mass ranges of 78 to 108 and 123 to 155 have been measured in the thermal neutron–induced fission of 235U by using an off-line gamma-ray spectrometric technique. The post-neutron mass yield distribution was obtained from the cumulative yields after applying the charge distribution correction. The data from present and earlier work of our laboratory in the 235U(nth,f) reaction were compared with similar data of 229Th(nth,f), 245Cm(nth,f), and 252Cf(SF) reactions to examine the fine structure in the mass yield distribution for four different even-even fissioning systems with charge of 90 to 98. The comparison shows that the fine structure in the mass yield distribution depends on spherical and deformed neutron shell combinations. The shell combination favors the standard I asymmetric mode of fission in the 235U(nth,f) and 245Cm(nth,f) reactions, whereas it favors the standard II asymmetric mode of fission in the 229Th(nth,f) and 252Cf(SF) reactions.

Post-Neutron Mass Yield Distribution in the Epi-Cadmium Neutron-Induced Fission of 241Am

Mass yield distribution has been carried out in the epi-cadmium neutron-induced fission of 241Am by measuring the cumulative yields of fission products within the mass ranges of 80 to 119 and 123 to 161. An off-line gamma-ray spectrometric technique was used for the measurement. From the cumulative yields of the fission products, mass chain yields were obtained by applying the charge distribution correction. From the mass yield distribution, the full-width at tenth-maximum of the light and heavy mass wings, the peak-to-valley (P/V) ratio, the average light mass <AL> and heavy mass <AH>, and the average number of neutrons <ν> were obtained. The mass yield data in the epi-cadmium neutron fission of 241Am were compared with similar data of thermal and 14.8-MeV neutron-induced fission to examine the role of excitation energy on the nuclear structure effect and P/V ratio.

Post-Neutron Mass Yield Distribution in the Thermal Neutron Induced–Fission of 239Pu

Mass chain yield distribution has been done in the thermal neutron–induced fission of 239Pu by measuring the cumulative yields of various fission products within the mass range of 78 to 159 and the independent yields of a few products. An off-line gamma-ray spectrometric technique was used to measure the gamma-ray activities of the fission products. From the measured values of the cumulative yields, the post-neutron mass chain yield distribution was obtained after applying the charge distribution correction. Data from the present and earlier work of our laboratory in the 239Pu(nth,f) reaction were compared with similar data of 238,241Pu(nth,f) and 240Pu(n,f) reactions, and it was found that the fine structures of the mass yield distributions are similar. The mass yield distribution in the 239Pu(nth,f) reaction was also compared with those of 229Th(nth,f) and 252Cf(SF) reactions to examine the effect of charge and mass difference of the fissioning systems on the mass yield distribution. It was found that the asymmetric standard I mode of fission is favorable in the 238,239,241Pu(nth,f) and 240Pu(n,f) reactions whereas the standard II mode is favorable in the 229Th(nth,f) and 252Cf(SF) reactions.

Post-neutron mass yield distribution in the epi-cadmium neutron induced fission of 243Am

The cumulative yields of fission products within the mass range of 83 to 119 and 123 to 158 have been measured in the epi-cadmium neutron-induced fission of 243Am by using an off-line gamma-ray spectrometric technique. Mass chain yields were obtained from the cumulative yields of the fission products by applying the charge distribution correction. From the mass yield data, the full-width at tenth-maximum of the light and heavy mass wing, the peak-to-valley (P/V) ratio, the average light mass <AL> and heavy mass <AH>, and the average number of neutrons <ν> were obtained. The mass yield data in the 243Am(n,f) reaction were compared with similar data in the 243Am(nth,f) and 243Am(n16.5 MeV,f) reactions to examine the role of excitation energy on the nuclear structure effect and P/V ratio.

Radioactive heat production characterization of Ar-Rassafeh Badyieh area (area-2), Syria by using aerial gamma ray spectrometric and fractal modeling techniques

Aerial gamma-ray spectrometric technique is used herein to evaluate the radioactive heat production (HP) of Ar-Rassafeh Badyieh Area (Area-2), Syria. The nine already established lithological scored units of Area-2 have been separately characterized for the heat production HP parameter. The Concentration-number (C-N) model and the log-log plots associated with fractal technique are proposed and applied as a new approach to map the measured equivalent uranium (eU), the equivalent thorium (eTh), and potassium (K%) and the computed heat production (HP) of Area-2. The HP of Area-2 varies between a minimum of 0.06 and a maximum of 4.28 ?w/m3 with an average of 0.548 ?w/m3 and a standard deviation of 0.27?w/m3. The highest observed HP values are related to the phosphatic environments represented by two lithological scored units A and B.

Post-Neutron Mass Yield Distribution in the Thermal Neutron Induced Fission of 232U

In the thermal neutron–induced fission of 232U, cumulative and independent yields of various fission products within the mass ranges of 72 to 107 and 123 to 158 have been measured using an off-line gamma-ray spectrometric technique. The fission yields were determined relative to the yield of a monitor product 92Sr. Charge distribution correction was applied on the cumulative yields to obtain the post-neutron mass yield distribution. Mass yield distribution parameters such as full-width at tenth-maximum of light and heavy mass wings, average light mass number <AL> and heavy mass number <AH>, and average number of emitted neutrons <ν> were obtained. Data from the present and earlier work on the 232U(nth,f) reaction were compared with similar data of the 235U(nth,f) reaction. It was found that the mass chain yield distribution in the 232U(nth,f) reaction is asymmetric with two major humps as in the case of the 235U(nth,f) reaction. Besides this, in the 232U(nth,f) reaction, the mass yield distribution shows a small third hump for the symmetric fission products. It was also found that the standard II asymmetric mode of fission is favorable in the 232U(nth,f) reaction whereas the standard I asymmetric mode of fission is favorable in the 235U(nth,f) reaction.

Heavy metals concentrations and naturally occurring radionuclides in soils affected by and around a solid waste dumpsite in Osogbo metropolis, Nigeria.

The presence of heavy metals and naturally occurring radioactive materials (NORMs) in high concentrations in soils can be hazardous to exposed humans. This study is aimed at measuring the concentrations of heavy metals (Cu, Pb, Ni, Zn, Cd, Co, and Cr) and activity concentration of 232Th, 238U, and 40K in soils affected by and around a solid waste dumpsite in Osogbo metropolis, Nigeria. Atomic absorption spectrometry and gamma-ray spectrometric techniques were used to determine the concentrations of metals and NORMs, respectively. Possible environmental impact of the heavy metal content and the probable radiological hazard by the NORMs to the general public were assessed. The calculated pollution indices reported in this work for Co, Cr, Pb, and Ni show low pollution status. Geoaccumulation indices for Cu, Zn, and Cd indicated that the area under study is strongly contaminated by these metals. Evaluated ecological risk index narrowed down Cd as the poisonous metal with high concentration. The measured radionuclides' mean activity concentrations and the evaluated mean of radium equivalent and absorbed dose rate values are higher than the recommended safe limit, an indication of possible radiological hazard. The principal factor analysis results explained 76% of the collection of data and described chips of galvanized/chrome metals, scrap metals, waste from electronics, Cr, and Cd-containing waste as sources of the heavy metals. The practice of land cultivation around the dumpsite should be deterred to prevent the transportation of these vicious heavy metals into the food chain.

Measurement of the 124Xe (n,2n) reaction cross section induced by 14.8 MeV neutron

The measurement of the 124Xe(n, 2n)123Xe reaction cross section at 14.8 MeV neutron has been performed by the activation method. Quasi monoenergetic neutron beams were produced at the Cockcroft Walton Accelerator of China Institute of Atomic Energy, by the T(d, n)4He reaction. A cell made of polymethyl methacrylate (PMMA) was used as the container of 124Xe (99.95% abundance) gas, and the mass of 124Xe in cell was determined by weighing method. Two high-purity thin 93Nb foils were attached to the cell and performed as monitors of the neutron flux determination by 93Nb(n, 2n)92mNb reaction. After the irradiation, the activities of 123Xe and 92mNb were measured by off-line gamma-ray spectrometric technique using a pre-calibrated HPGe detector. As a result, the cross section has been deduced at 14.8 MeV, and the result was compared with the literature data and evaluations.

Post-Neutron Mass Yield Distribution in the Epi-Cadmium Neutron-Induced Fission of 237Np

Mass yield distribution in the epi-cadmium neutron-induced fission of 237Np has been carried out by measuring the cumulative yields of fission products within the mass ranges of 78 to 117 and 123 to 157. A radiochemical and off-line gamma-ray spectrometric technique was used for the measurement. From the cumulative yields of the fission products, mass chain yields were obtained by applying the charge distribution correction. Mass yield distribution parameters such as the full-width at tenth-maximum of light and heavy mass wings, the peak-to-valley (P/V) ratio, and the average light mass <AL> and heavy mass (<AH>) as well as the average number of neutrons <ν> were obtained. The mass yield data in the epi-cadmium neutron-induced fission of 237Np were compared with the similar data in thermal and 14.5- to 14.7-MeV neutrons to examine the role of excitation energy in nuclear structure effect and P/V ratio.

Post-Neutron Mass Yield Distribution in the Spontaneous Fission of 252Cf

Cumulative and independent yields of various fission products within mass ranges of 86 to 119 and 127 to 162 were measured in the spontaneous fission of 252Cf by using an off-line gamma-ray spectrometric technique. From the cumulative yields of the fission products, their mass chain yields were obtained by using the charge distribution correction. Mass yield distribution parameters such as full-width at tenth-maximum of light and heavy mass wings, average light mass <AL> and heavy mass <AH>, and total average neutron multiplicity <ν>expt were obtained. Fission yield data in the 252Cf(SF) reaction were compared with similar data in neutron-induced fission and spontaneous fission of other actinides to examine the role of excitation energy and nuclear structure effect. The role of standard I and standard II asymmetric modes of fission is also discussed.

Black sand deposits; their spatial distribution and hazards along the northern coast of Sinai Peninsula, Egypt

Airborne Gamma Ray Spectrometric (AGRS) surveys and image processing techniques are utilized to define the occurrence of black sand deposits along Sinai's northern coastal plain. High contents of radioactive minerals are detected in these deposits; zones of high concentrations of uranium 238U, thorium 232Th, and potassium 40K could be outlined. Remote sensing and GIS techniques are integrated to study the pattern of coastline changes and its relationship to the distribution of black sand deposits during the period between 2000 and 2020. The results reveal high 232Th anomalies along El-Arish Beach due to its high monazite content; containing 7.92% ThO2. In addition, high uranium anomalies on the eastern sides of El-Bardawil Lake result from the abundance of zircon in the sediments surrounding the lake, which contain 5.29% U3O8. Areas of high radiation levels, which exceed the allowed limits for human exposure, are outlined by calculating adsorbed and annual effective dose rates. Unfortunately, many of these areas are open and easily accessible to the public, presenting a direct threat to the health of local inhabitants. These anomalous areas ought to be excluded from the ongoing national housing and land reclamation projects, where long-term exposure to high gamma radiation increases the cancer risk factor in humans.