Boris Pritychenko | Brookhaven National Laboratory (original) (raw)

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Papers by Boris Pritychenko

Nuclear Data Sheets, 2015

ABSTRACT Present contribution represents a first application of ENDF/B-VII.1 neutron library for ... more ABSTRACT Present contribution represents a first application of ENDF/B-VII.1 neutron library for calculation of Maxwellian-averaged cross sections and astrophysical reaction rates. Recent improvements in neutron cross section evaluations and more extensive utilization of covariance files, by the CSEWG collaboration, allowed us to perform complete calculations and provide additional insights on all currently available neutron-induced reaction data. Nuclear reaction calculations using ENDF libraries and current Java technologies will be discussed and new results will be presented. This work was sponsored by the Office of Nuclear Physics, Office of Science of the U.S. Department of Energy, under Contract No. DE-AC02-98CH10886 with Brookhaven Science Associates, LLC.

Nuclear astrophysics and californium fission neutron spectrum averaged cross sections and their u... more Nuclear astrophysics and californium fission neutron spectrum averaged cross sections and their uncertainties for ENDF materials have been calculated. Absolute values were deduced with Maxwellian and Mannhart spectra, while uncertainties are based on ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0 and Low-Fidelity covariances. These quantities are compared with available data, independent benchmarks, EXFOR library, and analyzed for a wide range of cases. Recommendations for neutron cross section covariances are given and implications are discussed.

Nuclear Data Sheets, 2012

We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals,... more We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellianaveraged cross sections and astrophysical reaction rates for 843 ENDF materials using data from the major evaluated nuclear libraries and European activation file. Extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate nuclear industry and neutron physics quantities, produce s-process Maxwellian-averaged cross sections and astrophysical reaction rates, systematically calculate uncertainties, and provide additional insights on currently available neutron-induced reaction data. Nuclear reaction calculations are discussed and new results are presented. Due to space limitations, the present paper contains only calculated Maxwellian-averaged cross sections and their uncertainties. The complete data sets for all results are published in the Brookhaven National Laboratory report.

Nuclear Data Sheets, 2015

Nuclear astrophysics and californium neutron spectrum cross sections and their uncertainties for ... more Nuclear astrophysics and californium neutron spectrum cross sections and their uncertainties for ENDF materials have been calculated. Absolute values were deduced with Maxwellian and Mannhart spectra, while uncertainties are based on ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0 and Low-Fidelity covariances. These quantities are compared with available data, independent benchmarks, EXFOR library, and analyzed for a wide range of cases. Recommendations for neutron cross section covariances are given and implications are discussed.

Present contribution represents a significant improvement of our previous calculation of Maxwelli... more Present contribution represents a significant improvement of our previous calculation of Maxwellian-averaged cross sections and astrophysical reaction rates. Addition of newlyevaluated neutron reaction libraries, such as ROSFOND and Low-Fidelity Covariance Project, and improvements in data processing techniques allowed us to extend it for entire range of sprocess nuclei, calculate Maxwellian-averaged cross section uncertainties for the first time, and provide additional insights on all currently available neutron-induced reaction data. Nuclear reaction calculations using ENDF libraries and current Java technologies will be discussed and new results will be presented.

Present contribution represents a significant improvement of our previous calculation of Maxwelli... more Present contribution represents a significant improvement of our previous calculation of Maxwellian-averaged cross sections and astrophysical reaction rates. Addition of newly-evaluated neutron reaction libraries, such as ROSFOND and Low-Fidelity Covariance Project, and improvements in data processing techniques allowed us to extend it for entire range of s-process nuclei, calculate Maxwellian-averaged cross section uncertainties for the first time, and provide additional

Stellar nucleosynthesis is an important nuclear physics phenomenon that is responsible for presen... more Stellar nucleosynthesis is an important nuclear physics phenomenon that is responsible for presently observed chemical elements and isotope abundances. It is also one of the corner stone hypotheses that provides basis for our understanding of Nature. Its theoretical predictions are often verified through the astrophysical observation and comparison of calculated isotopic abundances with the observed values. These calculations depend heavily

Nuclear Physics News, 2012

Nuclear Data Sheets, 2014

A new evaluation of 2β-decay half lives and their systematics is presented. These data extend the... more A new evaluation of 2β-decay half lives and their systematics is presented. These data extend the previous evaluation and include the analysis of all recent measurements. The nuclear matrix elements for 2β-decay transitions in 12 nuclei have been extracted. The recommended values are compared with the large-scale shell-model, QRPA calculations and experimental works. T 2ν 1/2 ∼ 1/E 8 systematic trend has been observed for 128,130 Te recommended values. Such trend indicates similarities for nuclear matrix elements in Te nuclei and was predicted for 2β(2ν)-decay mode. The complete list of results is available online at http://www.nndc.bnl.gov/bbdecay/.

Recommended 2β(2ν) half-life values and their systematics were analyzed in the framework of a sim... more Recommended 2β(2ν) half-life values and their systematics were analyzed in the framework of a simple empirical approach. T 2ν 1/2 ∼ 1 E 8 trend has been observed for 128,130 Te recommended values. This trend was used to predict T 2ν 1/2 for all isotopes of interest. Current results were compared with other theoretical and experimental works.

Nuclear reaction data play an important role in nuclear reactor, medical, and fundamental science... more Nuclear reaction data play an important role in nuclear reactor, medical, and fundamental science and national security applications. The wealth of information is stored in internally adopted ENDF-6 and EXFOR formats. We present a complete calculation of resonance integrals, Westcott factors, thermal and Maxwellian-averaged cross sections for Z=1-100 using evaluated nuclear reaction data. The addition of newly-evaluated neutron reaction libraries, and improvements in data processing techniques allows us to calculate nuclear industry and astrophysics parameters, and provide additional insights on all currently available neutron-induced reaction data. Nuclear reaction calculations will be discussed and an overview of the latest reaction data developments will be given.

Atomic Data and Nuclear Data Tables, 2014

Physical Review C

The 0(g.s.)(+)-->2(1)(+) excitation in the proton-rich nucleus Ne-18 has been studied via inte... more The 0(g.s.)(+)-->2(1)(+) excitation in the proton-rich nucleus Ne-18 has been studied via intermediate energy heavy-ion scattering with a beam of this radioactive isotope. The observed gamma-ray yields have been combined with coupled channels calculations of the inelastic scattering reactions to obtain the electromagnetic matrix element B(E2;0(g.s.)(+)-->2(1)(+)). This result is combined with the corresponding results in the mirror nucleus O-18 and the T=1 states in the N=Z nucleus F-18 as a test of isospin purity.

Nuclear Data Sheets, 2015

ABSTRACT Present contribution represents a first application of ENDF/B-VII.1 neutron library for ... more ABSTRACT Present contribution represents a first application of ENDF/B-VII.1 neutron library for calculation of Maxwellian-averaged cross sections and astrophysical reaction rates. Recent improvements in neutron cross section evaluations and more extensive utilization of covariance files, by the CSEWG collaboration, allowed us to perform complete calculations and provide additional insights on all currently available neutron-induced reaction data. Nuclear reaction calculations using ENDF libraries and current Java technologies will be discussed and new results will be presented. This work was sponsored by the Office of Nuclear Physics, Office of Science of the U.S. Department of Energy, under Contract No. DE-AC02-98CH10886 with Brookhaven Science Associates, LLC.

Nuclear astrophysics and californium fission neutron spectrum averaged cross sections and their u... more Nuclear astrophysics and californium fission neutron spectrum averaged cross sections and their uncertainties for ENDF materials have been calculated. Absolute values were deduced with Maxwellian and Mannhart spectra, while uncertainties are based on ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0 and Low-Fidelity covariances. These quantities are compared with available data, independent benchmarks, EXFOR library, and analyzed for a wide range of cases. Recommendations for neutron cross section covariances are given and implications are discussed.

Nuclear Data Sheets, 2012

We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals,... more We present calculations of neutron thermal cross sections, Westcott factors, resonance integrals, Maxwellianaveraged cross sections and astrophysical reaction rates for 843 ENDF materials using data from the major evaluated nuclear libraries and European activation file. Extensive analysis of newly-evaluated neutron reaction cross sections, neutron covariances, and improvements in data processing techniques motivated us to calculate nuclear industry and neutron physics quantities, produce s-process Maxwellian-averaged cross sections and astrophysical reaction rates, systematically calculate uncertainties, and provide additional insights on currently available neutron-induced reaction data. Nuclear reaction calculations are discussed and new results are presented. Due to space limitations, the present paper contains only calculated Maxwellian-averaged cross sections and their uncertainties. The complete data sets for all results are published in the Brookhaven National Laboratory report.

Nuclear Data Sheets, 2015

Nuclear astrophysics and californium neutron spectrum cross sections and their uncertainties for ... more Nuclear astrophysics and californium neutron spectrum cross sections and their uncertainties for ENDF materials have been calculated. Absolute values were deduced with Maxwellian and Mannhart spectra, while uncertainties are based on ENDF/B-VII.1, JEFF-3.1.2, JENDL-4.0 and Low-Fidelity covariances. These quantities are compared with available data, independent benchmarks, EXFOR library, and analyzed for a wide range of cases. Recommendations for neutron cross section covariances are given and implications are discussed.

Present contribution represents a significant improvement of our previous calculation of Maxwelli... more Present contribution represents a significant improvement of our previous calculation of Maxwellian-averaged cross sections and astrophysical reaction rates. Addition of newlyevaluated neutron reaction libraries, such as ROSFOND and Low-Fidelity Covariance Project, and improvements in data processing techniques allowed us to extend it for entire range of sprocess nuclei, calculate Maxwellian-averaged cross section uncertainties for the first time, and provide additional insights on all currently available neutron-induced reaction data. Nuclear reaction calculations using ENDF libraries and current Java technologies will be discussed and new results will be presented.

Present contribution represents a significant improvement of our previous calculation of Maxwelli... more Present contribution represents a significant improvement of our previous calculation of Maxwellian-averaged cross sections and astrophysical reaction rates. Addition of newly-evaluated neutron reaction libraries, such as ROSFOND and Low-Fidelity Covariance Project, and improvements in data processing techniques allowed us to extend it for entire range of s-process nuclei, calculate Maxwellian-averaged cross section uncertainties for the first time, and provide additional

Stellar nucleosynthesis is an important nuclear physics phenomenon that is responsible for presen... more Stellar nucleosynthesis is an important nuclear physics phenomenon that is responsible for presently observed chemical elements and isotope abundances. It is also one of the corner stone hypotheses that provides basis for our understanding of Nature. Its theoretical predictions are often verified through the astrophysical observation and comparison of calculated isotopic abundances with the observed values. These calculations depend heavily

Nuclear Physics News, 2012

Nuclear Data Sheets, 2014

A new evaluation of 2β-decay half lives and their systematics is presented. These data extend the... more A new evaluation of 2β-decay half lives and their systematics is presented. These data extend the previous evaluation and include the analysis of all recent measurements. The nuclear matrix elements for 2β-decay transitions in 12 nuclei have been extracted. The recommended values are compared with the large-scale shell-model, QRPA calculations and experimental works. T 2ν 1/2 ∼ 1/E 8 systematic trend has been observed for 128,130 Te recommended values. Such trend indicates similarities for nuclear matrix elements in Te nuclei and was predicted for 2β(2ν)-decay mode. The complete list of results is available online at http://www.nndc.bnl.gov/bbdecay/.

Recommended 2β(2ν) half-life values and their systematics were analyzed in the framework of a sim... more Recommended 2β(2ν) half-life values and their systematics were analyzed in the framework of a simple empirical approach. T 2ν 1/2 ∼ 1 E 8 trend has been observed for 128,130 Te recommended values. This trend was used to predict T 2ν 1/2 for all isotopes of interest. Current results were compared with other theoretical and experimental works.

Nuclear reaction data play an important role in nuclear reactor, medical, and fundamental science... more Nuclear reaction data play an important role in nuclear reactor, medical, and fundamental science and national security applications. The wealth of information is stored in internally adopted ENDF-6 and EXFOR formats. We present a complete calculation of resonance integrals, Westcott factors, thermal and Maxwellian-averaged cross sections for Z=1-100 using evaluated nuclear reaction data. The addition of newly-evaluated neutron reaction libraries, and improvements in data processing techniques allows us to calculate nuclear industry and astrophysics parameters, and provide additional insights on all currently available neutron-induced reaction data. Nuclear reaction calculations will be discussed and an overview of the latest reaction data developments will be given.

Atomic Data and Nuclear Data Tables, 2014

Physical Review C

The 0(g.s.)(+)-->2(1)(+) excitation in the proton-rich nucleus Ne-18 has been studied via inte... more The 0(g.s.)(+)-->2(1)(+) excitation in the proton-rich nucleus Ne-18 has been studied via intermediate energy heavy-ion scattering with a beam of this radioactive isotope. The observed gamma-ray yields have been combined with coupled channels calculations of the inelastic scattering reactions to obtain the electromagnetic matrix element B(E2;0(g.s.)(+)-->2(1)(+)). This result is combined with the corresponding results in the mirror nucleus O-18 and the T=1 states in the N=Z nucleus F-18 as a test of isospin purity.