Conveners
Theory/Codes: I
- Ionel Stetcu (LANL)
Theory/Codes: II
- Toshiiko Kawano (LANL)
Theory/Codes: III
- James Benstead (AWE)
Theory/Codes: IV
- Goran Arbanas (ORNL)
Theory/Codes: V
- Ian Thompson
Theory/Codes: VI
- Gregory Potel Aguilar
Theory/Codes: VII
- Marc Dupuis
Theory/Codes: VIII
- Jutta Escher
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Ian Thompson26/07/2022, 11:15
Charged-particle-induced reactions at low energies in the resolved resonance region are important for a range of applications in basic and applied sciences. Ion Beam Analysis of materials for cultural heritage, environment and climate control, and forensics, depends on the knowledge of proton-, deuteron- and alpha-induced reactions at energies of a few MeV. Management of fuel in nuclear...
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Ian Thompson (LLNL)26/07/2022, 11:39
The R-matrix method of Lane and Thomas is the standard procedure for modelling resonances at low energies, to determine widths and angular distributions needed for nuclear evaluations. Many different codes have been written, all with different input and output file formats. To ensure that results can be replicated, I have written a python code FERDINAND using FUDGE to read & write ENDF, GNDS...
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Gustavo Nobre (BNL)26/07/2022, 11:51
The different processes known in astrophysics to govern the successions of nuclear formation and decay, r-process and s-process, depend strongly on nuclear properties such as the intrinsic density of levels of a given nucleus and how they behave when emitting or absorbing particles such as neutrons, protons and/or photons. There are few experimental constraints that we can use to narrow down...
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Mr Benedikt Raab (TU WIEN)26/07/2022, 12:03
Three-body break-up channels play an important role in light nuclear systems even at low incident energies. In standard two-body R-matrix theory these processes can only be treated approximatively for instance by using sequential decay models. We will present a novel three-body R-matrix formalism that is based on a proposal by Glöckle [1]. In this framework the Faddeev equations are solved by...
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Marc Dupuis (CEA, DAM, DIF)27/07/2022, 06:00
Nucleon inelastic scattering to the continuum can be adequately described through the exciton or quantum mechanical multistep direct (MSD) and multistep compound (MSC) pre-equilibrium models, as they account not only for the high energy component of particle emission spectrum, but also it provides initial conditions of the formed Compound Nucleus (CN).
It was previously shown that an ...
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Toshihiko Kawano (Los Alamos National Laboratory)27/07/2022, 06:24
Neutron inelastic scattering is one of the major nucleon-nucleus interactions in the fast energy range, and its cross section constantly increases above the threshold energy of the first excited state up to a few MeV. Since the inelastic scattering process changes the momentum of interacting neutrons and produces characteristic gamma-rays, high quality nuclear data for this process are...
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Satoshi Kunieda (Japan Atomic Energy Agency)27/07/2022, 06:36
For thorough understanding resonant theories and cause of discrepancies among different cross-section measurements, development of an R-matrix analysis code AMUR is being progressed.
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The code is organized by “theoretical” and “experimental” classes based on the object-oriented framework. In the theoretical class, with sharing the same compound nucleus, the independent distant poles can... -
Thomas Srdinko27/07/2022, 06:48
A versatile R-matrix module for multi-channel reaction calculations was developed which allows not only phenomenological R-matrix analyses, but also extensions to new and non-standard formulations of R-matrix theory such as the Reduced R-matrix formulation and the hybrid R-matrix concept. An important feature of the module is the capability to combine standard R-matrix analysis with the result...
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James Benstead (AWE)27/07/2022, 07:00
A survey has been conducted of the resonance data available in the major evaluated libraries for a range of mid-mass isotopes. Although many isotopes have data derived from experimental measurements and rigorous analyses, the data for some others, particularly for isotopes that are unstable, are purely theoretically generated, e.g. via the use of the TARES code.
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A subsequent project has... -
Dr Luiz Leal (IRSN)27/07/2022, 07:12
Reich-Moore (RM) approach has been extensively used in the resolved resonance energy range (RRR) for a wide range of isotopes. The Reich-Moore approximation was suggested late in the fifties for cross section representation of fissile isotopes since experimental fission width distribution according to given resonance spin and parity showed that only a few degrees of freedom (DoF) was involved...
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Dr Sophie Péru (CEA, DAM, DIF)27/07/2022, 07:45
The Gogny-based QRPA approach developed in CEA, DAM, DIF [1] can be applied to spherical as well as to axially deformed nuclei, from light (i.e. oxygen) to superheavy elements [2]. For electric and magnetic dipole modes, intensive computational efforts have been made to produce a large-scale data set of gamma-ray strength functions with as little as possible phenomenological corrections. The...
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Emanuel Chimanski (Instituto Tecnológico de Aeronáutica)27/07/2022, 08:09
Nuclear structure and inelastic scattering have key roles in the study of the origin of elements in the Universe as well as in the modern medical treatments. A precise knowledge of reaction rates and particle absorption are of fundamental importance in the mass aggregation mechanism of r-process and increase the accuracy of radio isotopes production and radiation therapies. The theoretical...
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Dr Odsuren Myagmarjav (School of Engineering and Applied Sciences and Nuclear Research Center, National University of Mongolia, Ulaanbaatar 210646, Mongolia)27/07/2022, 08:21
The first excited $1/2^+$ state in $^9$Be has been observed as a sharp peak just above the $^8$Be+$n$ threshold energy in the photo-disintegration cross section of $^9$Be. Since the size of the peak has a strong influence on the reaction rate of the $^9$Be synthesis, experimental data have been investigated [1, 2].
We performed calculations using an $\alpha+\alpha+n$ three-cluster model [3,...
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Hirokazu Sasaki (LosAlamos National Laboratory)27/07/2022, 08:33
The giant dipole resonance (GDR) is one of the most well-known collective excitation modes since the dawn of research on nuclear physics. The origin of GDR is a collective motion of neutrons against protons inside the nucleus. Since its discovery in the photoabsorption cross section, extensive theoretical studies have been done to reveal the nature of such electric dipole excitation. The...
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Arthur Beloeuvre (Subatech)27/07/2022, 08:45
First-forbidden beta decays play an important role in several domains of physics. First, in astrophysics, where nuclear data such as the half-life govern stellar evolution and nucleosynthesis [1]. Second, they are of interest for nuclear reactors physics as first highlighted in 2014 [2]. In first-forbidden $\beta$-decays, the form factor of the leptonic spectra are not equal to one as for...
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Konstantinos Kravvaris27/07/2022, 11:00
First-principles calculations have made great strides during the past years in bridging the gap from fundamental nuclear interactions derived from chiral effective field theory to the description of nuclear structure and dynamics. Due to their predictive capability, large-scale calculations can form the basis on which nuclear data evaluations can be performed. In this talk, I will outline a...
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Xiaojun Sun (Guangxi Normal University)27/07/2022, 11:24
Based on the statistical theory of light nucleus reactions, the description of the complicated emission processes of proton and light composite charged particles are further improved through considering the effects of Coulomb barriers both in incident and different outgoing reaction channels. Moreover, the analysis of the reaction channels including the sequential and simultaneous emission...
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Igor Moskalenko (Stanford University)27/07/2022, 11:36
A series of benchmark experiments with thin targets was carried out at ITEP in 1994 - 2009 in support of subcritical systems with an external neutron source (Accelerator Driven Systems, ADS) [1-3].
The cross sections for the formation of residual products of nuclear reactions were determined by the activation method ͟using precision γ-spectrometry. Thin samples made of material considered...
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Wendi Chen (Beihang University)27/07/2022, 11:48
It is an open question in the fields of nuclear reactions to study the mechanism of reactions induced by the weakly bound nuclei at different incident energies with various target nuclei and calculate the reaction cross sections. The structure of weakly bound nuclei, which is easily broken up, plays an important role in their induced reaction and is thought to be the main reasons for their...
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Alessandro Baroni (Los Alamos National Laboratory)28/07/2022, 06:00
It is reasonable to believe that in the not-too-distant future, quantum computing will revolutionize our ability to model and understand atomic nuclei and their interactions, and will find applications well beyond basic research. Advances in technologies that allow the production of quantum hardware with a larger number of qubits and significantly smaller error rates are still a few years...
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Kelsey Lund (North Carolina State University)28/07/2022, 06:24
The rapid neutron capture (r-process) is one of the main mechanisms whereby elements heavier than iron are synthesized, and is responsible for the creation of the heaviest stable isotopes of the actinides. Kilonova emissions are modeled as being largely powered by the radioactive decay of species synthesized via the r-process and in principle, observations of these offer insight into...
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Shoto Watanabe (Hokkaido University)28/07/2022, 06:36
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Oliver Gorton (San Diego State University)28/07/2022, 06:48
Currently, reaction measurements on fission products are being planned by the Nuclear Science PG at both Argonne Nat. Lab and at FRIB (Facility for Rare Isotopes, Michigan State). These indirect experiments produce specific short-lived nuclei via beta decay, and the subsequent neutron and gamma emission are studied. Some initial experiments found a surprising overabundance of gamma emission....
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Boris Pritychenko (NNDC, BNL)28/07/2022, 07:00
Recommended 2$\beta$(2$\nu$) half-lives and their systematics [1] are examined in the framework of a semi-empirical approach. Impacts of nuclear deformation, transition energy, and forbidden decay on half-live values were observed. These findings were used to predict T$_{1/2}$ for 35 isotopes of interest. Current results are compared with other theoretical and experimental works.
[1] B....
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Catherine Apgar (Department of Nuclear Engineering, University of California, Berkeley, Berkeley, California 94720, USA)28/07/2022, 07:12
The Auger-emitting nuclides $^{119}Sb$ (for which $^{119m}Te$ is a generator) and $^{117m}Sn$ are promising candidates for the treatment of small tumors and for use in radiosynoviorthesis, but there is little information available regarding the formation of these nuclei when targets are bombarded with high energy protons in large-scale isotope production facilities. A more precise cross...
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Adriana Sweet (LLNL)28/07/2022, 07:50
Our understanding of neutron-induced reactions on nuclei far from stability
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has far reaching implications for cosmogenic nucleosynthesis and fundamental
nuclear physics. Direct measurement of the radiative-capture cross section is experimentally inaccessible for these short-lived nuclei; however, indirect methods such as the ?$\beta$-Oslo Method enable the experimental constraint of key... -
Jutta Escher (Lawrence Livermore National Laboratory)28/07/2022, 08:14
The availability of reliable nuclear data with quantified uncertainties is essential for basic and applied science. The last decade has seen much progress in the development of theory tools that allow us to achieve more accurate evaluations for compound (statistical) nuclear reactions. Integrated nuclear structure and reaction descriptions provide the basis for achieving consistent evaluations...
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Dr Olivier Bouland (CEA Cadarache France)28/07/2022, 08:26
Since its introduction, the so-called surrogate-reaction method (SRM) has motivated the development and improvement of theories in connection to direct reactions. A recent paper~\cite{bou:20} has shown that the assimilation of experimental probabilities in the neutron cross section evaluation process can still be better estimated using tools resulting from the efforts made over the two last...
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Toshihiko Kawano (Los Alamos National Laboratory)28/07/2022, 08:38
Fluctuation in the observed resonance decay widths is often characterized by the Porter-Thomas distribution, or the chi-square distribution. Compound nucleus reaction modelings, in which the Gaussian Orthogonal Ensemble (GOE) is involved as a propagator, have been successfully applied to study the properties of fluctuation in the S-matrix (or the cross section). In the GOE models, the...
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Goran Arbanas (ORNL)28/07/2022, 08:50
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Dr Marilena Avrigeanu (Horia Hulubei National Institute for Physics and Nuclear Engineering (IFIN-HH))28/07/2022, 09:02
\documentclass[aps,prc,groupedaddress,amsmath,amssymb,12pt,tightenlines]{revtex4}
\usepackage{graphics}
\usepackage{longtable}\begin{document}
\title{Role of direct interactions in $(d,p)$ and $(d,2p)$ reactions}
\author{M.~Avrigeanu} \email{marilena.avrigeanu@nipne.ro}
\author{C.~Costache}
\author{V.~Avrigeanu}\affiliation{Horia Hulubei National Institute for Physics and Nuclear...
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383. Evaluation of the neutron-induced cross sections of actinides using the CONRAD computer programGilles Noguere (CEA, DEN Cadarache)28/07/2022, 09:40
The CONRAD computer code is being developed by the nuclear data group of CEA Cadarache by since mid-2000. It was originally designed to analyse neutron-induced reactions in the resonance energy range and then, was extended to higher energies (several MeV) treatment with inclusion of charged-particles penetration factor. In the resonance range, nuclear models implemented in the CONRAD program...
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Roberto Capote (IAEA NDS)28/07/2022, 10:04
A comprehensive reevaluation of $^{239}$Pu transport cross sections from subthermal energies up to 30 MeV within the INDEN collaboration is presented. Softer prompt fission neutron spectra (PFNS) for thermal neutron-induced fission with an average energy of 2.08 MeV from the IAEA evaluation is combined with new resonance parameters and new nubar evaluation to preserve the good criticality...
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Dr Olivier Bouland (CEA Cadarache France)28/07/2022, 10:16
The evaluation state-of-the-art according to the $^{239}$Pu(n,2n) angular-integrated reaction cross section is well synthesized by Fig.1, enclosed, on which are drawn from one side, experimental data and on the other side, some major evaluated curves. Recent evaluations, by contrast to the old JEF-2.2 data file, remain consistent except near threshold and at energies above the maximum of the...
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Gregory Potel Aguilar (LLNL)28/07/2022, 10:28
Neutron-induced cross sections on fissile nuclei such as $^{239}$Pu are important for defense and energy applications, as well as for basic science. The quality of these values rely on two basic pillars: a) the availability of high-quality, curated experimental data. Within this context, it is essential to constantly update the existing database with the new experiments carried out in...
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Carole Chatel (CEA)28/07/2022, 10:40
The neutron fission cross section of the 242Pu target nucleus is being studied both experimentally and theoretically since at least five decades. Past studies include early measurements and derived resonance analyses as those by Auchampaugh et al. [1,2] and Weigmann et al. [3] and, since 2008, date of a renewed High Priority Request List demand according to the fission experimental data, a new...
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Vasilis Vlachoudis (CERN)28/07/2022, 11:30
FLUKA [1,2,3] is a multipurpose Monte Carlo code for the simulation of particle transport and interaction with matter. FLUKA relies on dedicated models for hadronic interactions, with the notable exception of low-energy neutrons (below 20 MeV), for which a group-wise treatment based on evaluated nuclear data has been employed for a sizable list of relevant isotopes. A point-wise treatment was...
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Dr Francesc Salvat Pujol (European Organization for Nuclear Research (CERN)), Gabriela Moryc (European Organization for Nuclear Research (CERN))28/07/2022, 11:43
A dedicated model for low-energy (<150 MeV/n) deuteron nuclear reactions has been a long-standing shortcoming of FLUKA [1-3], a general-purpose code for the Monte Carlo simulation of radiation transport. In view of the recently increasing interest in deuteron transport (e.g. for radioisotope production in medical applications [4-5] and for nuclear fusion studies [6]), a model for...
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Michael Rising (LANL)28/07/2022, 11:55
The CGMF code, which models the correlated particle emissions from fission events of various spontaneous and neutron-induced fissile systems, is now available as open-source software [1]. In the previous release of MCNP, version 6.2, the CGMF code was integrated and was optionally available to perform inline low-energy fission event simulations targeted toward nuclear nonproliferation and...
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Camilo Cordero Ramirez (CEA)28/07/2022, 12:07
Nuclear data in the different libraries (ENDF/B, JEFF, JENDL, CENDL) for the description of the outgoing particles are very often expressed as averaged distributions. This is the case, for example, of the (n,2n) reaction, for which we find only one energy distribution with a multiplicity equal to 2. The situation is quite similar for neutron capture (n,g) with an average photon number and an...
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Dr Igor Moskalenko (Stanford University)28/07/2022, 12:19
Modern theoretical studies and industrial applications related to the design, radiation protection, and reliability of nuclear facilities, medical applications, as well as space research and exploration are relying on extensive simulations and modeling. Computer codes realizing various semi-classical and quantum molecular dynamics (QMD) approaches are often employed to make up for the lack of...
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Dr Hairui Guo (Institute of Applied Physics and Computational Mathematics)
Optical model is one of the most fundamental theoretical models in nuclear reaction theory. It is applied widely in various nuclear reaction calculations. The microscopic optical potential (MOP) is generated theoretically based on the nucleon-nucleon interaction, which has no free parameters and does not depend on experimental data. The MOPs for nucleon, 2,3H, 3,4,6He and 6,7Li are obtained in...
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Mark Paris (LANL T-2)
Resonance parametrizations of nuclear scattering and reaction observables are useful for applications in nuclear astrophysics, nuclear energy and nuclear safety and security. Such parametrizations derived from the phenomenological $R$-matrix -- a Green-function approach -- afford compact and accurate descriptions of the relevant observables and their uncertainties as determined by the observed...
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Tanja Stary
R-matrix theory is a unique tool to provide quantitatively reliable descriptions of resonant scattering and reaction processes in nuclear systems. Albeit it is not a microscopic theory and lacks predictive power the method is widely used for analyses of experimental reaction data because it satisfies major conservation rules thus leading to consistent descriptions of collision processes....
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Mr Dmitry Martyanov (Joint Institute for Power and Nuclear Research - Sosny)
The recently developed multiband dispersive optical model with soft rotator nuclear model couplings is used to build a regional potential for fissile actinides. The model allows coupled-channel calculations for odd-A targets considering rotational bands built on vibrational states. Those complex vibrational states are characterized by a coupling of single-particle excitations with the...
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Dr Xavier Mougeot (Université Paris-Saclay, CEA, List, Laboratoire National Henri Becquerel (LNE-LNHB), F-91120 Palaiseau, France)
Over the past decade, forbidden non-unique beta transitions have been identified to be of critical importance in several fundamental physics topics, such as the modelling of antineutrino flux from nuclear reactors or from the Earth, and the background modelling in dark matter experiments. The decay half-lives of long-lived beta-emitting radionuclides, which exhibit a high degree of...
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