Download or read book Evaluation of the 239Pu n 2n Integrated Cross Section written by and published by . This book was released on 2001 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recently, new cross section measurements by the GEANIE collaboration have been published for 239Pu(n, 2n[gamma]) [Ber00] and 235U(n, 2n[gamma]) [You00] from threshold to 20 MeV. When combined with nuclear reaction calculations [Che00, Cha99, Cha01], these measurements provide the most accurate information available on the shape and magnitude of the 239Pu(n, 2n) cross section for incident neutron energies, E{sub n} ≈
Download or read book Alternate Approach to the 239Pu n 2n Cross Section written by and published by . This book was released on 2000 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using existing experimental data for neutron-induced total, elastic, inelastic, reaction and fission cross sections, as well as results from nuclear model calculations and evaluations from nuclear reaction data libraries, we derived an estimate for the cross sections for the 235U(n,2n) and 239Pu(n,2n) reactions for the neutron energy range from threshold to approximately 12 MeV. In effect, our approach is based on subtracting the fission and inelastic cross sections from the total reaction cross section where the difference is expected to yield the (n,2n) cross section. In addition to this subtraction approach, a ratio method and a differential method have also been explored. For 235U(n,2n), as a test case, we arrive at a cross section consistent with previous measurements, and for 239Pu(n,2n) we obtain a peak value of 400 " 60 mb for the incident neutron energy range of 10 (less-than or equal to) E{sub n} (less-than or equal to) 12 MeV.
Download or read book Calculation of 239Pu n 2n Cross Section by the Subtraction and the Ratio Methods written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The 239Pu(n,2n) and the 235U(n,2n) cross section are estimated by applying unitarity in several approaches: a subtraction method and also by using a ratio approach that relates the above cross sections to the 238U(n,2n) cross section and the 239Pu(n,2n) cross section to the 235U(n,2n) cross section, respectively. Also, a self-consistent, simultaneous analysis of the cross section data of four nuclei, 239Pu, 235U, 238U and 232Th, was undertaken to evaluate the 239Pu(n,2n) cross section at 11 MeV.
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 The 239 Pu n 2n 238 Pu Cross Section Preliminary Calculations written by and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary motivation for the present work is to provide theoretical values for the ratio of the partial 239Pu(n,2nxy)238Pu to total 239Pu(n,2n)238Pu cross section for several discrete gamma transitions. Results and conclusions of preliminary calculations from threshold to 20 MeV are presented. Calculations are based on theoretical models with parameters obtained from the literature or from our ad hoc systematics. Optical model cross sections and transmission coefficients were determined using the coupled-channels method. The calculations included a preequilibrium component followed by multiple particle and gamma-ray emissions. Fission competition was included at all stages of de-excitation. Suggestions for further verifications and possible improvements are provided.
Download or read book Systematics and Evaluation of n 2n and n 3n Cross sections written by V. N. Manokhin and published by . This book was released on 1996 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The 239 Pu n 2n 238Pu Cross Section written by and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary motivation for the present work is to provide theoretical values for the ratio of the partial 239Pu(n,2nx?)238Pu to total 239 Pu(n,2n)238Pu cross section for several discrete gamma transitions. Results and conclusions of preliminary calculations from threshold to 20 MeV are presented. Calculations are based on theoretical models with parameters obtained from the literature or from our ad hoc systematics. Optical model cross sections and transmission coefficients were determined using the coupled-channels method. The calculations included a preequilibrium component followed by multiple particle and gamma-ray emissions. Fission competition was included at all stages of de-excitation. Suggestions for further verifications and possible improvements are provided.
Download or read book Evaluation of the Cross sections for the Reactions 19 n 2n 18 31 n p 31i 93b n n 93Nb and 103h n n 103Rh written by B. Strohmaier and published by . This book was released on 1980 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1976 with total page 1292 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Evaluation of Nuclear Reaction Cross sections for 239Pu in the Resonance Energy Region with a View to Compiling a Complete File of Constants written by V.A. Kon'shin and published by . This book was released on 1975 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Handbook of Nuclear Engineering written by Dan Gabriel Cacuci and published by Springer Science & Business Media. This book was released on 2010-09-14 with total page 3701 pages. Available in PDF, EPUB and Kindle. Book excerpt: This is an authoritative compilation of information regarding methods and data used in all phases of nuclear engineering. Addressing nuclear engineers and scientists at all levels, this book provides a condensed reference on nuclear engineering since 1958.
Download or read book Calculation of 239pu n N Cross Sections to 5 MeV written by and published by . This book was released on 2000 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Calculations of the 239Pu(n, n') cross section and other relevant cross sections for incident neutron energies of up to 5 MeV are presented. Two components of the 239Pu(n, n') cross section are included. The direct contribution to the 239Pu(n, n') cross section is computed by the coupled-channel optical model. The compound component is calculated by a Hauser-Feshbach statistical treatment. Fission and [gamma]-cascade processes are considered as competing channels in the compound-decay process. Whenever possible, calculations are compared with experimental data and evaluations.
Download or read book Evaluation of Fission Cross Sections and Covariances 233U 235U 238U 239Pu 240Pu and 241Pu written by and published by . This book was released on 2000 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Los Alamos Science written by and published by . This book was released on 2005 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Publications of the National Bureau of Standards Catalog written by United States. National Bureau of Standards and published by . This book was released on 1975 with total page 618 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ERDA Energy Research Abstracts written by United States. Energy Research and Development Administration and published by . This book was released on 1976 with total page 980 pages. Available in PDF, EPUB and Kindle. Book excerpt:
