Development of a reference database for beta-delayed neutron emission

Dimitriou, P.*; Dillmann, I.*; Singh, B.*; Piksaikin, V.*; Rykaczewski, K. P.*; Tain, J. L.*; Algora, A.*; Banerjee, K.*; Borzov, I. N.*; Cano-Ott, D.*; et al.

Nuclear Data Sheets, 173, p.144 - 238, 2021/03

https://doi.org/10.1016/j.nds.2021.04.006

-delayed neutron emission has been of interest since the discovery of nuclear fission. In nuclear power reactors, delayed-neutron data play a crucial role in reactor kinetics calculations and safe operation. -delayed neutron data also have a significant impact in the field of nuclear structure and astrophysics especially as nuclei farther away from stability are explored at the new generation of radioactive beam facilities. Several compilations of -decay half-lives and delayed-neutron emission probabilities are available, however, complete documentation of measurements and evaluation procedures is often missing for these properties. Efforts to address this gap in nuclear data and create an updated compilation and evaluation of -delayed neutron properties were undertaken under the auspices of the International Atomic Energy Agency (IAEA) which formed a Coordinated Research Project (CRP) on "Development of a Reference Database of Beta-delayed Neutron Emission Data". In this paper we summarize the work that was performed and present the results of the CRP.

Matrix-material dependence on the elongation of embedded gold nanoparticles induced by 4 MeV C and 200 MeV Xe ion irradiation

Li, R.*; Narumi, Kazumasa*; Chiba, Atsuya*; Hirano, Yu*; Tsuya, Daiju*; Yamamoto, Shunya*; Saito, Yuichi*; Okubo, Nariaki; Ishikawa, Norito; Pang, C.*; et al.

Nanotechnology, 31(26), p.265606_1 - 265606_9, 2020/06

https://doi.org/10.1088/1361-6528/ab7e70

We report the elongation of embedded Au nanoparticles (NPs) in three different matrices under irradiations of 4 MeV C ions and 200 MeV Xe ions. Large elongation of Au NPs was observed for crystalline indium tin oxide (ITO) under both 4 MeV C and 200 MeV Xe irradiation. The ITO layer preserved the crystallinity even after large elongation was induced. This is the first report of the elongation of metal NPs in a crystalline matrix.

Role of multichance fission in the description of fission-fragment mass distributions at high energies

Hirose, Kentaro; Nishio, Katsuhisa; Tanaka, Shoya*; Lguillon, R.*; Makii, Hiroyuki; Nishinaka, Ichiro*; Orlandi, R.; Tsukada, Kazuaki; Smallcombe, J.*; Vermeulen, M. J.; et al.

Physical Review Letters, 119(22), p.222501_1 - 222501_6, 2017/12

https://doi.org/10.1103/PhysRevLett.119.222501

Fission-fragment mass distributions were measured for U, Np and Pu populated in the excitation-energy range from 10 to 60 MeV by multi-nucleon transfer channels in the reaction O + U at the JAEA tandem facility. Among them, the data for U and Np were observed for the first time. It was found that the mass distributions for all the studied nuclides maintain a double-humped shape up to the highest measured energy in contrast to expectations of predominantly symmetric fission due to the washing out of nuclear shell effects. From a comparison with the dynamical calculation based on the fluctuation-dissipation model, this behavior of the mass distributions was unambiguously attributed to the effect of multi-chance fission.

Study of fission using multi-nucleon transfer reactions

Nishio, Katsuhisa; Hirose, Kentaro; Lguillon, R.*; Makii, Hiroyuki; Orlandi, R.; Tsukada, Kazuaki; Smallcombe, J.*; Chiba, Satoshi*; Aritomo, Yoshihiro*; Tanaka, Shoya*; et al.

Proceedings of 6th International Conference on Fission and Properties of Neutron-rich Nuclei (ICFN-6), p.590 - 597, 2017/11

https://doi.org/10.1142/9789813229426_0101

Fission fragments mass distributions of nuclei populated by the multinucleon transfer channels of the O + Th reaction

Lguillon, R.; Nishio, Katsuhisa; Hirose, Kentaro; Makii, Hiroyuki; Nishinaka, Ichiro*; Orlandi, R.; Tsukada, Kazuaki; Smallcombe, J.*; Chiba, Satoshi*; Aritomo, Yoshihiro*; et al.

Physics Letters B, 761, p.125 - 130, 2016/10

https://doi.org/10.1016/j.physletb.2016.08.010

Identified charged hadron production in collisions at = 200 and 62.4 GeV

Adare, A.*; Afanasiev, S.*; Aidala, C.*; Ajitanand, N. N.*; Akiba, Yasuyuki*; Al-Bataineh, H.*; Alexander, J.*; Aoki, Kazuya*; Aphecetche, L.*; Armendariz, R.*; et al.

Physical Review C, 83(6), p.064903_1 - 064903_29, 2011/06

https://doi.org/10.1103/PhysRevC.83.064903

Transverse momentum distributions and yields for , and in collisions at = 200 and 62.4 GeV at midrapidity are measured by the PHENIX experiment at the RHIC. We present the inverse slope parameter, mean transverse momentum, and yield per unit rapidity at each energy, and compare them to other measurements at different collisions. We also present the scaling properties such as and scaling and discuss the mechanism of the particle production in collisions. The measured spectra are compared to next-to-leading order perturbative QCD calculations.

A Dispersive, lane-consistent coupled-channel optical model based on soft-rotator theory for accurate calculation of nuclear reaction data

Chiba, Satoshi; Soukhovitski, E. Sh.*; Capote, R.*; Quesada, J.*

Proceedings of 2009 International Congress on Advances in Nuclear Power Plants (ICAPP '09) (CD-ROM), p.9172_1 - 9172_7, 2009/05

Coupled-channels optical model code OPTMAN is widely applied to analyze experimental nucleon-nucleus interaction data. Sophisticated dispersive optical potential forms had been included in the code along with the possibility to calculate direct excitations of isobar analog states in (p,n) reactions. The latter along with accounting of the proton "effective" energy decrease due to Coulomb repulsion by nuclei, leads to full Lane-consistent optical potential. Such approach had been successfully applied to nucleon-nucleus interaction reaction analyses of experimental data for several nuclei up to 200 MeV incident energies.

A Global dispersive coupled-channel optical model potential for actinides

Capote, R.*; Chiba, Satoshi; Soukhovitskij, E. Sh.*; Quesada, J. M.*; Bauge, E.*

Journal of Nuclear Science and Technology, 45(4), p.333 - 340, 2008/04

https://doi.org/10.3327/jnst.45.333

A global dispersive coupled-channel optical model (DCCOM) potential is proposed to describe neutron and proton interactions with actinide nuclei at 0.001 to 200 MeV range. A linear dependence of the geometrical parameters on mass number is employed, and deformation parameters are adjusted for each nucleus to extend the DCCOM determined previously for U and Th to neighboring nuclei, Am, Pu and U. Fitted deformations are in reasonable agreement with those derived theoretically. The present DCCOM is capable of describing not only the cross sections but also the total cross section differences between Th and U up to 200 MeV within experimental uncertainty, verifying that the isovector potential and assumed geometrical parameters are adequate to describe the minute difference of the cross sections of actinide nuclei and its energy dependence.

Angular distributions of protons scattered by Ar nuclei with excitation of the 2 (1.46 MeV) and 3 (3.68 MeV) collective levels for incident energies of 25.1, 32.5, and 40.7 MeV

Okumusoglu, N. T.*; Gorur, F. K.*; Birchall, J.*; Soukhovitskij, E. Sh.*; Capote, R.*; Quesada, J. M.*; Chiba, Satoshi

Physical Review C, 75(3), p.034616_1 - 034616_10, 2007/03

https://doi.org/10.1103/PhysRevC.75.034616

Elastic and inelastic scattering of unpolarized and polarized protons by Ar nuclei for incident energies between 20 and 50 MeV has been studied by reanalyzing experimental scattering spectra for the 2 (1.46 MeV) and 3 (3.68 MeV) levels in the angular range 30 - 160 for incident protons of energies of 25.1, 32.5, and 40.7 MeV. An isospin dependent soft-rotator coupled channels optical model with the potential containing a dispersive term with a nonlocal contribution is used to analyze the data.

Is a global coupled-channel dispersive optical model potential for actinides feasible?

Capote, R.*; Soukhovitskij, E. Sh.*; Quesada, J. M.*; Chiba, Satoshi

Physical Review C, 72(6), p.064610_1 - 064610_6, 2005/12

https://doi.org/10.1103/PhysRevC.72.064610

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