The interaction of silver with 300-GeV protons was studied and compared with that of 11.5-GeV protons. Cross section ratios, o'&00/o'f f 5 were determined for 74 nuclides ranging from 'Be to ' 6Ag . The weighted average value of o300/o&& 5 is 1.01+0.10. A detailed examination of the dependence of the ratios on product A and N/Z reveals that the only difference occurs in the A -20-30 mass region, where a 17 + 5% increase in cross sections is observed at 300 GeV.NUCLEAR REACTIONS Ag+ 300-GeV protons; measured o for formation of 74 nuclides ranging from 'Be to ' Ag; compared with corresponding o. at 11.5GeV.
Thermal neutrons from the Budapest Research Reactor and fast neutrons from theBerkeley Neutron Generator Facility have been used to analyze fissile materials. It has been shown that both prompt and delayed gamma rays from neutron capture and fission product decays can be used to analyze both uranium concentrations and 235 U enrichments. Spontaneous fission neutron emission from 238 U decay has also been found to be useful for uranium analysis. Detection of high-energy gamma rays following the decay of short-lived fission products was shown to be a sensitive indicator of fissile material, and the ratio of fission product gamma ray intensities can uniquely determine the concentrations of fission isotopes. IntroductionThe analysis of uranium and plutonium has gathered increasing importance in problems including nuclear waste remediation, nuclear nonproliferation, and battlefield exposure to depleted uranium. Th and 238 U with cross sections ranging from 0.1-1 b for neutron energies >2 MeV. In this work we have investigated the feasibility of analyzing fissile materials with 2.5 MeV neutrons produced at the Berkeley Neutron Generator Facility 3 .We will also discuss the analysis of 238 U by the detection of fast neutrons following the small, 5.45×10 -5 %, spontaneous fission decay branch 4 . Experimental Budapest Reactor ExperimentsExperiments were conducted at both the Budapest Research Reactor using cold and thermal guided neutron beams. Berkeley D+D Neutron Generator ExperimentsThe Berkeley D+D neutron generator 3 utilizes RF-induction discharge to generate deuterium plasma. The neutron generator is based on a co-axial design, which maximizes the target area in compact outer dimensions of the generator and enables operation at high beam power, thus yielding high neutron fluxes. The generator was typically operated at an acceleration voltage of 120 kV and 50 mA deuterium beam current. This beam power yielded a ≈2.5 MeV neutron flux of >10 9 n/s. Gamma rays were detected with a 20% efficient, relative to 3"×3" NaI, HPGe detector. The efficiency was calibrated with a certified multinuclide calibration source from Isotope Product Laboratories. Spontaneous fission neutrons were detected with a 3 He neutron detector that also served as a flux monitor for the neutron generator. A 0.89 kg target of uranium, depleted to 0.1% in 235 U, was counted to obtain the natural 238 U gamma ray spectrum. It was then irradiated next to the neutron generator for 10 minutes, manually removed from the irradiation chamber, and counted for 6 minutes, starting 1 minute after bombardment. A larger, 14.65 kg, sample of the same depleted uranium was counted directly with the 3 He neutron detector. Results and Discussion Budapest Reactor DataThe prompt and delayed gamma ray spectra produced following the irradiation of uranium enriched to 36% in 235 U is shown in Figure 1. Prompt gamma rays are observed up to 10 MeV, and the spectrum is dominated by a plethora of fission and continuum capture gamma rays. Several prompt gamma rays from neutron...
Prompt gamma activation analysis (PGAA) has been used to analyze metal ion oxyanion materials that have multiple applications, including medicine, materials, catalysts, and electronics. The significance for the need for accurate, highly sensitive analyses for the materials is discussed in the context of quality control of end products containing the parent element in each material. Applications of the analytical data for input to models and theoretical calculations related to the electronic and other properties of the materials are discussed. IntroductionElemental analyses for a wide array of elements in the Periodic Table are of extreme value for a wide range of purposes, including trying to gain a knowledge of materials failure when it occurs, modeling the electronic, magnetic, and chemical properties, and assessing and verifying quality control of the purity of the materials in which they are found. Both the elements and their compounds are useful for an extremely wide variety of applications in chemistry and materials science, including applications that are dependent on the elements' magnetic, electronic, and physical properties as well as their ability to form compounds and complexes. In obtaining precise analytical data for materials, the analyst may need a technique which will give really good, high-quality analytical data while preserving the integrity of the samples for archival purposes.The materials that have been analyzed in the present study represent an eclectic group of elements that are important from a wide number of standpoints. Additionally, in many cases, the counteranions associated with the central elements in the materials can be of extreme importance in the compound's role as synthetic precursors for other materials where the original materials or compounds have really good advantages as starting materials. Beryllium nitrate, for example, can be used as a starting material for the synthesis of beryllium oxide, 1 which is used in an extremely wide variety of applications ranging from sophisticated electronic materials 2 to dopants in gemstones 3 to dental materials. 4 It also represents, however, an element whose toxicity in humans 5,6 makes it extremely important as an analytical target due to many applications that impact both humans and the environment. Magnesium sulfate is widely used in medical and biomedical applications, 7 while scandium and its compounds (including the sulfate analyzed here) act as precursors in the synthesis of materials as well as serve as materials on their own. 8 Antimony is used in a wide variety of applications employing mixed elemental oxides, including catalysts, alloys, and magnetic materials. 9 Gallium is used for a wide assortment of electronic materials such as gallium arsenide, 10 many of which demand extremely high purity and quality control. Lead has applications in materials including powders, electronic devices, and ceramics 11 and also an extensive biochemistry and toxicology, 12 all areas of interest areas necessitating the ability to obtain de...
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