Download or read book Report on 238Pu n X Surrogate Cross Section Measurement written by and published by . This book was released on 2010 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this year's effort is to measure the 238Pu(n, f) and 238Pu(n,2n) cross section from 100 keV to 20 MeV. We designed a surrogate experiment that used the reaction 239Pu(a, a(prime)x) as a surrogate for 238Pu(n, x). The experiment was conducted using the STARS/LIBERACE experimental facility located at the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory in January 2010. A description of the experiment and status of the data analysis is given. In order to obtain a reliable 238Pu(n, x) cross section we designed the experiment using the surrogate ratio technique. This technique allows one to measure a desired, unknown, cross section relative to a known cross section. In the present example, the 238Pu(n, x) cross section of interest is determined relative to the known 235U(n, x) cross section. To increase confidence in the results, and to reduce overall uncertainties, we are also determining the 238Pu(n, x) cross section relative to the known 234U(n, x) cross section. The compound nuclei of interest for this experiment were produced using inelastic alpha scattering. For example, 236U(a, a(prime)x) served as a surrogate for 235U(n, x); analogous reactions were considered for the other cross sections. Surrogate experiments determine the probabilities for the decay of the compound nuclei into the various channels of interest (fission, gamma decay) by measuring particle-fission (p-f) or particle?gamma (p?g) reaction spectra. By comparing the decay probabilities associated with the unknown cross section to that of a known cross section it is possible to obtain the ratio of these cross sections and thus determine the unknown, desired cross section.
Download or read book Report on 240Am n X Surrogate Cross Section Test Measurement written by and published by . This book was released on 2012 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main goal of the test measurement was to determine the feasibility of the 243Am(p, t) reaction as a surrogate for 24°Am(n, f). No data cross section data exists for neutron induced reactions on 24°Am; the half-life of this isotope is only 2.1 days making direct measurements difficult, if not impossible. The 48-hour experiment was conducted using the STARS/LIBERACE experimental facility located at the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory in August 2011. A description of the experiment and results is given. The beam energy was initially chosen to be 39 MeV in order to measure an equivalent neutron energy range from 0 to 20 MeV. However, the proton beam was not stopped in the farady cup and the beam was deposited in the surrounding shielding material. The shielding material was not conductive, and a beam current, needed for proper tuning of the beam as well as experimental monitoring, could not be read. If the 24°Am(n, f) surrogate experiment is to be run at LBNL, simple modifications to the beam collection site will need to be made. The beam energy was reduced to 29 MeV, which was within an energy regime of prior experiments and tuning conditions at STARS/LIBERACE. At this energy, the beam current was successfully tuned and measured. At 29 MeV, data was collected with both the 243Am and 238U targets. An example particle identification plot is shown in Fig. 1. The triton-fission coincidence rate for the 243Am target and 238U target were measured. Coincidence rates of 0.0233(1) cps and 0.150(6) cps were observed for the 243Am and 238U targets, respectively. The difference in count rate is largely attributed to the available target material - the 238U target contains approximately 7 times more atoms than the 243Am. A proton beam current of H".7 nA was used for measurements on both targets. Assuming a full experimental run under similar conditions, an estimate for the run time needed was made. Figure 2 shows the number of days needed as a function of acceptable uncertainty for a measurement of 1-20 MeV equivalent neutron energy, binned into 200 keV increments. A 5% measurement will take 3 days for U, but 20 days for Am. It may be difficult to be the sole user of the LBNL cyclotron, or another facility, for such an extended period. However, a 10% measurement will take 19 hours for U, and 5 days for Am. Such a run period is more reasonable and will allow for the first ever measurement of the 24°Am(n, f) cross section. We also anticipate 40% more beam time being available at Texas A & M Cyclotron Institute compared to LBNL in FY2012. The increased amount of beam time will allow us to accumulate better statistics then what would have been available at LBNL.
Download or read book Report on 241 242Am n X Surrogate Cross Section Measurement written by and published by . This book was released on 2011 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main goal of this measurement is to determine the 242Am(n, f) and 241Am(n, f) cross sections via the surrogate 243Am. Gamma-ray data was also collected for the purpose of measuring the (n,2n) cross-sections. The experiment was conducted using the STARS/LIBERACE experimental facility located at the 88 Inch Cyclotron at Lawrence Berkeley National Laboratory the first week of February 2011. A description of the experiment and status of the data analysis follow.
Download or read book 239Pu n 2n 238Pu Cross Section Inferred from IDA Calculations and GEANIE Measurements written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents the latest 239Pu(n,2n)238Pu cross sections inferred from calculations performed with the nuclear reaction-modeling code system, IDA, coupled with experimental measurements of partial [gamma]-ray cross sections for incident neutron energies ranging from 5.68 to 17.18 MeV. It is found that the inferred 239Pu(n,2n)238Pu cross section peaks at E{sub inc} ≈ 11.4 MeV with a peak value of approximately 326 mb. At E{sub inc} ≈ 14 MeV, the inferred 239Pu(n,2n)238Pu cross section is found to be in good agreement with previous radio-chemical measurements by Lockheed. However, the shape of the inferred 239Pu(n,2n)238Pu cross section differs significantly from previous evaluations of ENDL, ENDF/B-V and ENDF/B-VI. In our calculations, direct, preequilibrium, and compound reactions are included. Also considered in the modeling are fission and [gamma]-cascade processes in addition to particle emission. The main components of physics adopted and the parameters used in our calculations are discussed. Good agreement of the inferred 239Pu(n,2n)238Pu cross sections derived separately from IDA and GNASH calculations is shown. The two inferences provide an estimate of variations in the deduced 239Pu(n,2n)238Pu cross section originating from modeling.
Download or read book Measurement of the Fission Cross Section of 238Pu written by and published by . This book was released on 1986 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The fission cross sections of 238Pu have been measured from 0.1 eV to 80 keV energy range using the Rensselaer Intense Neutron Spectrometer. The cross sections were normalized to the 235U ENDF/B-V data broadened to the resolution of the Rensselaer Intense Neutron Spectrometer system. The fission areas and widths were determined for the resolved low-energy resonances. The ENDF/B-V fission cross sections for the 238Pu isotope are, in general, not in good agreement with the measured cross sections and a new evaluation is recommended. The observations of structure in the unresolved fission cross sections is suggestive of the existence of intermediate structure. 18 refs., 1 fig., 1 tab.
Download or read book Absolute and Relative Surrogate Measurements of the 236U n F Cross Section as a Probe for Angular Momentum Effects written by and published by . This book was released on 2007 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using both the absolute and relative surrogate techniques, the 236U(n, f) cross section was deduced over an equivalent neutron energy range of 0 to 20 MeV. A 42 MeV 3He beam from the 88-Inch Cyclotron at Lawrence Berkeley National Laboratory was used to perform a (3He, [alpha]) pickup reaction on targets of 235U (J{sup {pi}}=7/2−) and 238U (J{sup {pi}}=0) and the fission decay probabilities were determined. The 235U(3He, [alpha]f) and 238U(3He, [alpha]f) were surrogates for 233U(n, f) and 236U(n, f), respectively. The cross sections extracted using the Surrogate Method were compared to directly measured cross sections. The sensitivity of these cross sections to the J{sup {pi}}-population distributions was explored.
Download or read book Nuclear Reaction Data from Surrogate Measurements written by and published by . This book was released on 2007 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: A brief summary of the Surrogate reaction method, an indirect approach for determining compound-nuclear reaction cross sections, is presented. The possibilities for obtaining accurate (n, f) cross sections from Surrogate measurements that are analyzed in the Weisskopf-Ewing and Ratio approximations are considered. Theoretical studies and benchmark experiments that provide new insights into the validity and limitations of the Surrogate approach, are discussed.
Download or read book 14 MeV Neutrons written by Vladivoj Valkovic and published by CRC Press. This book was released on 2015-08-25 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt: Despite the often difficult and time-consuming effort of performing experiments with fast (14 MeV) neutrons, these neutrons can offer special insight into nucleus and other materials because of the absence of charge. 14 MeV Neutrons: Physics and Applications explores fast neutrons in basic science and applications to problems in medicine, the envir
Download or read book Guidelines on Soil and Vegetation Sampling for Radiological Monitoring written by International Atomic Energy Agency and published by . This book was released on 2019-10-21 with total page 247 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication addresses the sampling of soil and vegetation in terrestrial ecosystems, including agricultural, forest and urban environments, contaminated with radionuclides from events such as radiation accidents, radiological incidents and former nuclear activities. It considers sampling strategies and programmes, which are relevant for both emergency and existing exposure situations. Practical advice is provided on the design and implementation of sampling programmes for soil and vegetation within the framework of environmental monitoring. Examples of best practice on the formulation of optimized sampling strategies for different exposure situations are given based on the experience and lessons learned from implementation of past and existing programmes.
Download or read book Quantifying Uncertainty in Nuclear Analytical Measurements written by and published by . This book was released on 2004 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Dedicated specifically to nuclear analytical techniques, this publication is intended to assist scientists using alpha, beta and gamma spectrometries, neutron activation and XRF analyses, and other nuclear analytical methods, in assessing and quantifying the sources of uncertainty in their daily measurements.
Download or read book Nuclear Back end and Transmutation Technology for Waste Disposal written by Ken Nakajima and published by Springer. This book was released on 2014-11-05 with total page 331 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book covers essential aspects of transmutation technologies, highlighting especially the advances in Japan. The accident at the Fukushima Daiichi Nuclear Power Plant (NPP) has caused us to focus attention on a large amount of spent nuclear fuels stored in NPPs. In addition, public anxiety regarding the treatment and disposal of high-level radioactive wastes that require long-term control is growing. The Japanese policy on the back-end of the nuclear fuel cycle is still unpredictable in the aftermath of the accident. Therefore, research and development for enhancing the safety of various processes involved in nuclear energy production are being actively pursued worldwide. In particular, nuclear transmutation technology has been drawing significant attention after the accident. This publication is timely with the following highlights: 1) Development of accelerator-driven systems (ADSs), which is a brand-new reactor concept for transmutation of highly radioactive wastes; 2) Nuclear reactor systems from the point of view of the nuclear fuel cycle. How to reduce nuclear wastes or how to treat them including the debris from TEPCO’s Fukushima nuclear power stations is discussed; and 3) Environmental radioactivity, radioactive waste treatment and geological disposal policy. State-of-the-art technologies for overall back-end issues of the nuclear fuel cycle as well as the technologies of transmutation are presented here. The chapter authors are actively involved in the development of ADSs and transmutation-related technologies. The future of the back-end issues in Japan is very uncertain after the accident at the Fukushima Daiichi NPP and this book provides an opportunity for readers to consider the future direction of those issues.
Download or read book Modern Flow Analysis written by Pawel Koscielniak and published by . This book was released on 2020 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flow analysis is an automatic, precise and fast way to perform analytical tests. Flow instruments are used for clinical and pharmaceutical analyses, quality control of industrial products, monitoring of environmental pollution and many other fields. The book presents the latest methodological, technical and instrumental achievements in flow analysis. It shows new possibilities for the miniaturization and full mechanization of flow systems, together with examples of their interesting application. The proposed solutions contribute to reducing the amount of used reagents and waste, as well as increasing the safety of working with hazardous reagents, resulting in modern devices operating in accordance with the principles of green chemistry. A number of innovative methods of processing and measuring analytical samples have also been described. The book very well reflects the current state of flow analysis and development directions.
Download or read book Handbook of Radioactivity Analysis written by Michael F. L'Annunziata and published by Academic Press. This book was released on 2020-03-07 with total page 1076 pages. Available in PDF, EPUB and Kindle. Book excerpt: Handbook of Radioactivity Analysis: Radiation Physics and Detectors, Volume One, and Radioanalytical Applications, Volume Two, Fourth Edition, constitute an authoritative reference on the principles, practical techniques and procedures for the accurate measurement of radioactivity - everything from the very low levels encountered in the environment, to higher levels measured in radioisotope research, clinical laboratories, biological sciences, radionuclide standardization, nuclear medicine, nuclear power, and fuel cycle facilities, and in the implementation of nuclear forensic analysis and nuclear safeguards. It includes sample preparation techniques for all types of matrices found in the environment, including soil, water, air, plant matter and animal tissue, and surface swipes.Users will find the latest advances in the applications of radioactivity analysis across various fields, including environmental monitoring, radiochemical standardization, high-resolution beta imaging, automated radiochemical separation, nuclear forensics, and more. Spans two volumes, Radiation Physics and Detectors and Radioanalytical Applications Includes a new chapter on the analysis of environmental radionuclides Provides the latest advances in the applications of liquid and solid scintillation analysis, alpha- and gamma spectrometry, mass spectrometric analysis, Cherenkov counting, flow-cell radionuclide analysis, radionuclide standardization, aerosol analysis, high-resolution beta imaging techniques, analytical techniques in nuclear forensics, and nuclear safeguards Describes the timesaving techniques of computer-controlled automatic separation and activity analysis of radionuclides Provides an extensive table of the radiation characteristics of most radionuclides of interest for the radioanalytical chemist
Download or read book NUREG CR written by U.S. Nuclear Regulatory Commission and published by . This book was released on 1977 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Use of Low Enriched Uranium Fuel in Accelerator Driven Subcritical Systems written by International Atomic Energy Agency and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This publication presents the results and conclusions of an international research collaboration devoted to gaining a better understanding of the physics of Accelerator Driven Subcritical Systems (ADS), with particular emphasis on using low enriched uranium (LEU) fuel. The publication contains information on nine ADS facilities, including descriptions of the hardware deployed, experiments conducted, computational resources and procedures used in the analyses, principal results obtained, and conclusions drawn from the knowledge gained as a consequence of this work. It is intended to provide information for users of ADS systems and those involved in the design of new ADS facilities to use LEU fuel and in the conversion of some existing facilities from using highly enriched Uranium (HEU) to LEU.
Download or read book New Nuclear Data written by and published by . This book was released on 1957 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Prompt Gamma Activation Analysis written by G. Molnar and published by Springer Science & Business Media. This book was released on 2010-02-23 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: Prompt gamma activation analysis (PGAA) is a unique, non-destructive nuclear analytical method with multi-element capabilities. It is most effective if intense neutron beams (especially cold beams) of nuclear reactors are used to induce the prompt gamma radiation. Based largely on the authors' pioneering research in cold neutron PGAA, the handbook describes the methodology in self-contained manner and reviews recent applications. The library of prompt gamma ray data and spectra for all natural elements is a unique aid to the practitioner. The level is understandable by a broad audience, which facilitates teaching and training. The Handbook of Prompt Gamma Activation Analysis is a comprehensive handbook written for those practising the method, wanting to implement it at a reactor facility, or just looking for a powerful non-destructive method of element analysis. The book is also useful for nuclear physics, chemistry and engineering scientists, scholars and graduate students interested in neutron-induced gamma ray spectroscopy and nuclear analytical methods.
