bluuebunny/crossref_metadata_2025 huggingface dataset:
Broadband organic photodetectors based on ternary blend active layers with enhanced and spectrally flat response
Authors: Wang Jianbin , Chen Shan-Ci , Yin Zhigang , Zheng Qingdong
Published: September 2020

Under −25 V bias, the optimized ternary OPD exhibits a relatively flat EQE spectrum from 330 to 810 nm with an average EQE of 3.3 × 105% which is more than 40 times larger than that of the binary OPD.
Ageing state identification and analysis of AC 500 kV XLPE submarine cable based on high‐voltage frequency dielectric response
Authors: Dai Xize , Hao Jian , Jian Zheng , Gao Zhen , Cheng Jialu , Zheng Xinlong
Published: September 2020

Carrying out the insulation condition measurement and analysis is important for the safe operation of the submarine cable. In this study, the high‐voltage frequency dielectric response is used to identify the ageing state of the AC 500 kV cross‐linked polyethylene (XLPE) submarine cable. The complex capacitance and tanδ in the low‐frequency area for the new, thermal ageing, electro‐thermal ageing cable all increase with the testing voltage increased from 200 to 2000 V. It is founded that the dielectric response at high voltage is more likely to detect the ageing differences. Based on the carbonyl index and the dielectric loss of the XLPE specimens at different position of the insulation layer, the non‐uniform ageing phenomenon of the cable insulation is presented for the thermal ageing and electro‐thermal ageing cable. The loss quantity parameter and its changing behaviour with testing voltage based on the frequency dielectric response could be used to identify the ageing state. The comparison of the modified Cole–Cole model parameter under 200 and 2000 V also indicates that the higher voltage dielectric response is helpful to identify the ageing differences.
Temperature conditions in the ventilation shaft lining and the space behind lining when reversing the main ventilation unit in winter
Authors: Kurilko Aleksandr , Solovev Dmitrii
Published: September 2020

Using mathematical modeling methods, the authors studied the temperature changes in the ventilation shaft lining and the space behind lining under an alternating thermal effect of the ventilation flow (reversing the main ventilation unit in winter). We established the pattern of the temperature conditions created in the ventilation shaft, the lining, and the host rock mass when reversing the main ventilation unit at mines in the North. Our studies have shown that, in case of emergency at the mine, which requires reversing the air flow in the coldest period of the year, it will result in a change in the temperature conditions in the ventilation shaft, the concrete lining, and the host rock mass. The extent of such effect depends on the reverse duration. Thus, at an ambient temperature of -45°C, during the first 24 hours after the reverse, we can observe complete freezing of the concrete lining at a ventilation flow rate of over 2 m/s. The rock temperature drops below 0°C and, at air flow rates of up to 10 m/s, the frozen area thickness around the shaft will be no more than 7 cm. 48 hours after the reverse, the maximum freezing depth of the rock will be 30 cm.
Geomechanical conditions of vein gold deposits in permafrost zone
Authors: Avdeev Arkady , Sosnovskaya Elena
Published: September 2020

Developing the vein deposits in the permafrost zone results in specific geomechanical conditions. The paper describes the main results of studies of the geomechanical conditions of 8 vein deposits located in the permafrost zone for 2000-2020. In the process of research, zoning of the temperature conditions in mines has been carried out. The research has established the position of the permafrost zones, the natural transition zones of frozen rocks to thawed rocks, the zones of seasonal ventilation thawing and technogenic thawing. The authors have made the qualitative assessment of the degree of stability of the mine workings and pillars, taking into account the temperature conditions. It is proposed, when evaluating the stability of structural elements of geotechnologies, to adjust the strength properties of rocks using a differentiated coefficient of structural weakening. The paper has presented the results of field measurements of the initial stress-deformed state at various temperature conditions. The general regularities of the distribution of initial stresses are established: hydrostatic stresses act in frozen rocks, and increased gravitational-tectonic stresses act in natural and technogenic thawed rocks. The authors have proposed to use the obtained results as boundary conditions for the calculation of geotechnological parameters in the design and initial development of vein gold deposits of the permafrost zone. The authors have proposed the measures to improve the safety of mining operations in permafrost: thermal insulation of mine walls, use of electric transport, regulation of ventilation.
Use of mechanical activation in the processing of gold-bearing ores and anthropogenic materials
Authors: Litvinova Natalia , Kopylova Aleksandra , Stepanova Valentina , Tatsumi Hitachi
Published: September 2020

The results of experimental studies on the use of mechanical activation in the processing of ores and anthropogenic materials of the Far Eastern region are presented. The effectiveness of the use of electrophotoactivated solutions and complex reagents at the stage of mineral preparation has been established. Technological solutions have been proposed to reduce the loss of finely dispersed and chemically bonded gold during the processing of gold-bearing materials based on a directed change in the properties of the surface of minerals. The effectiveness of the use of the mechanochemical activation process for various aspects of the technological chain has been experimentally confirmed – a decrease in the sorption properties of materials, development of microcracks in oxidized ores for the penetration of leaching solutions into mineral aggregates, oxidation of the surface of primary ores, and removal of films from the mineral surface. Indicators of technological refractoriness of the studied ores and anthropogenic materials were revealed – a high proportion of chemically bound gold with atoms of basic and accessory mineral-forming elements, the presence of grains of the valuable component covered with oxide films, enclosed in carbonates, quartz and waste rock. The refractoriness of ores is confirmed by a high sorption capacity (the predominance of carbonaceous and clay matter), the presence of trace impurities in gold (Sb, As, Cu, Fe, Hg), which increase the consumption of cyanide during leaching. The material composition is dominated by a significant amount of chemical elements – cyanosides, actively interacting with the main complexing agent of leaching solutions – cyanide of alkali metals.
Selective flotation of phosphorus-bearing ores
Authors: Elbendari Abdalla , Aleksandrov Aleksandr , Nikolaeva Nadezhda , Afanasova Anastasiya
Published: September 2020

This paper presents the results of the beneficiation of a phosphorus-bearing mineral through selective flotation process. The chemical examination showed that the sample contain a low content of P2O5 12.5 % and significant amounts of rare earth elements (REE), %: yttrium - 0.01, lanthanum - 0.06, cerium - 0.09, neodymium - 0.03. The particle size distribution of the sample was performed, and each separated fraction was chemically analyzed. A detailed examination of the mineralog ical characteristics was conducted using automated mineral liberation analyzer (MLA). It has been shown that the apatite particles are mostly liberated in all fraction sizes. The maximum percentage of apatite polymineral aggregate was recorded in the grain size of -0.5 + 0.2 mm, mainly with nepheline and pyroxenes. The maximum percentage of apatite binary aggregate was noted in the grain size of -0.16 + 0.071 and -0.071 + 0.045 mm. Based on the obtained results, the size of the flotation feed was predetermined, which allowing the complete liberation of phosphorusbearing mineral (apatite) and avoiding over-grinding of the ore.
Intensification of humic acid extraction from lignites
Authors: Moskalenko Tatiana , Mikheev Valery , Vorsina Elena
Published: September 2020

One of the methods of initial properties of solid fuels changing by their organic mass oxidation is considered in the paper. Creation of innovative ways of intensification of existing solid fuels processing and their adoption by industry has always been and remains an actual task. Thus the chemical process is the most important stage of raw materials processing into target products. Chemical exposure allows to optimize the technological mode, expanding the scope of control of technological process parameters and, to a certain extent, modify the properties of the resulting products. The article presents the results of experimental research of influence of preliminary oxidation on the lignite organic mass from Kharanorsk and Kangalas deposits by different chemical reagents to determine a degree of this process impact on the efficiency of their processing into humic substances. Inorganic and organic oxidizers of different concentrations were used as reagents. The greatest effect for increasing the humic acids yield was observed when using 6-10 % hydrogen peroxide for oxidation, and 10 % hydrochloric acid. The results of experiments on the coal preoxidation effect can be used as a basis for the development of a new method of lignites processing into humic substances.
Technological, economic and social aspects of the provision of solid fuels to the Arctic regions of Yakutia
Authors: Tkach Sergye , Batugina Natalya , Gavrilov Vladimir
Published: September 2020

The article examines the reasons leading to the increase in the price of fuel and energy resources consumed in the Arctic regions of the Yakutia. The paper studies the conditions for the development of coal deposits in the region. It is shown the lack of open cast mines that meet modern criteria for efficient use of small-scale open mining by quality and logistic accessibility. This article determines that with the minimum level of clogging of the hard coal mined and the stabilization of its quality over time, it is possible to efficiently recycle the fuel without other precombustion measures. In the case of development of brown coal deposits, additional enrichment is required after extraction to improve the level of consumables. The paper stresses that development of local small-scale deposits of coal is important direction to improve energetic safety of arctic regions. It is necessary to select the coal mines most suitable for open-cast mining, as close to consumers and also with the best quality indicators. The use of the specified measures of technological and economic management, administrative regulation and improvement of mechanisms of «northern delivery» make it possible to facilitate the creation and operation of new coal mines in the Arctic zone of Yakutia. In turn, this reduce coal delivery periods, its quantity and quality losses in the supply chain, and improve local fuel and energy complexes.
Strategy of consolidation in gold mining as a tool for creating an effective business
Authors: Kradenykh Irina , Barchukov Aleksei
Published: September 2020

The subject of the article is the search for an effective strategic solution within the framework of sustainable development of gold mining enterprises belonging to small and medium-sized mining businesses. The purpose of the study is to analyze the problem and provide a theoretical justification for the feasibility of horizontal integration for this category of gold mining enterprises. The scientific article reveals the processes of development of the gold mining industry, taking into account the state of the mineral resource base of placer gold. The role of horizontal integration and the feasibility of its application in the framework of enterprises belonging to small and medium-sized mining businesses are outlined. A method for evaluating the effectiveness of a horizontally integrated gold mining enterprise is proposed, taking into account potential synergetic effects and the possibility of production diversification. These approaches, even at the project stage, will allow us to assess the feasibility and effectiveness of the planned consolidation.
Ground penetrating radar investigations of the geological structure of loose sediments at solid mineral deposits
Authors: Fedorova Larisa , Lejzerowicz Anna , Kulyandin Gavril , Savvin Denis , Fedorov Maksim
Published: September 2020

For effective commercial development of deposits, an increase in the information content of operational exploration is required. In recent years, the range of methods used to obtain complete and reliable information about the structure and properties of the rock mass of a developed field include remote methods of high-frequency electrical prospecting, in particular, the ground penetrating radar (GPR) method. The paper presents a methodological experience in the interpretation of GPR data of sandy river sediments based on the identification of radar facies. In the considered area, four types of radar facies have been identified that characterize the structure of sandy deposits and the morphology of the river bed. The criteria for identifying radar facies were used to analyze wave patterns of loose sediments in a sand and gravel pit and a placer gold deposit. Experimental GPR investigations are presented by data from a sandy-gravel pit (Warsaw, Poland) and from a placer gold deposit (Yakutia, Russia). As an example, a GPR section along the Paplin quarry and its interpretation, with the identification of GPR facies, is presented. A cross-sectional GPR profile of the dredging landfill is considered for the placer gold deposit. The analysis of the wave pattern was carried out, geological boundaries were highlighted. Based on the interpretation results, the characteristics of the rocks were given. It was noted that according to the GPR data, it is possible to identify zones of uplift of bedrock, which can affect the course of the dredge. As a result of using GPR in a swampy area where drilling was impossible, a deep three-layer section was obtained. The presented results of the successful use of GPR investigations and methodological approaches in the interpretation of data, show the promise of using the GPR method in assessing mining and geological conditions, in particular, placer deposits. At the same time, the efficiency of obtaining data can further contribute to the optimization of technology and increase the efficiency of field development.
GAINS: neutron inelastic cross section measurements of interest for applications and reaction studies
Authors: Negret A. , Borcea C , Boromiza M. , Dessagne Ph. , Henning Gr. , Kerveno M. , Nyman M. , Olacel A. , Plompen A.J.M
Published: September 2020

The paper represents an overview of the measurements performed using GAINS at GELINA (JRC-Geel, Belgium). While undergoing continuous upgrades, the setup produced highly precise cross sections. Our measurements are primarily driven by technological needs with an emphasis on structural materials used in the development of nuclear facilities. However, most cases offered the opportunity to investigate various reaction mechanism and/or nuclear structure issues. We concentrate on several specific experiments describing the particular difficulties we met and the solutions we adopted to infer reliable data and to draw significant conclusions.
Neutron capture cross section measurements of 241Am at the n_TOF facility
Authors: Oprea A. , Gunsing F. , Schillebeeckx P. , Aberle O. , Bacak M. , Berthoumieux E. , Cano-Ott D , Diakaki M. , Dupont E. , Geslot B. , Glodariu T. , Heyse J. , Mendoza E. , Negret A. , Alcayne V. , Amaducci S. , Andrzejewski J. , Audouin L. , Bécares V. , Babiano-Suarez V , Barbagallo M. , Becčvář F. , Bellia G. , Billowes J. , Bosnar D. , Brown A. , Busso M. , Caamaño M. , Caballero-Ontanaya L , Calviño F. , Calviani M. , Casanovas A. , Cerutti F. , Chen Y. H. , Chiaveri E. , Colonna N. , Cortés G. , Cortés-Giraldo M. A. , Cosentino L. , Cristallo S. , Damone L. A. , Dietz M. , Domingo-Pardo C , Dressler R. , Durán I. , Eleme Z. , Femández-Domínguez B. , Ferrari A. , Finocchiaro P. , Furman V. , Göbel K. , Garg R. , Gawlik A. , Gilardoni S. , Goncalves I. F. , González-Romero E. , Guerrero C. , Harada H. , Heinitz S. , Jenkins D. G. , Jericha E. , Käppeler F. , Kadi Y. , Kimura A. , Kivel N. , Kokkoris M. , Kopatch Y. , Krtička M. , Kurtulgil D. , Ladarescu I. , Lederer-Woods C , Lerendegui-Marco J , Meo S. Lo , Lonsdale S. J. , Macina D. , Manna A. , Martínez T. , Masi A. , Massimi C. , Mastinu P. , Mastromarco M. , Matteucci F. , Maugeri E. A. , Mazzone A. , Mengoni A. , Michalopoulou V. , Milazzo P. M. , Mingrone F. , Musumarra A. , Nolte R. , Ogállar F. , Patronis N. , Pavlik A. , Perkowski J. , Persanti L. , Porras I. , Praena J. , Quesada J. M. , Radeck D. , Ramos-Doval D , Reifarth R. , Rochman D. , Rubbia C. , Sabaté-Gilarte M. , Saxena A. , Schumann D. , Smith A. G. , Sosnin N. V. , Stamatopoulos A. , Tagliente G. , Tain J. L. , Talip T. , Tarifeño-Saldivia A. , Tassan-Got L , Torres-Sánchez P. , Tsinganis A. , Ulrich J. , Urlass S. , Valenta S. , Vannini G. , Variale V. , Vaz P. , Ventura A. , Vlachoudis V. , Vlastou R. , Wallner A. , Woods P. J. , Wright T. , Žugec P.
Published: September 2020

Neutron capture on 241Am plays an important role in the nuclear energy production and also provides valuable information for the improvement of nuclear models and the statistical interpretation of the nuclear properties. A new experiment to measure the 241Am(n, γ) cross section in the thermal region and the first few resonances below 10 eV has been carried out at EAR2 of the n_TOF facility at CERN. Three neutron-insensitive C6D6 detectors have been used to measure the neutron-capture gamma cascade as a function of the neutron time of flight, and then deduce the neutron capture yield. Preliminary results will be presented and compared with previously obtained results at the same facility in EAR1. In EAR1 the gamma-ray background at thermal energies was about 90% of the signal while in EAR2 is up to a 25 factor much more favorable signal to noise ratio. We also extended the low energy limit down to subthermal energies. This measurement will allow a comparison with neutron capture measurements conducted at reactors and using a different experimental technique.
Neutron inelastic cross section measurements on 54Fe
Authors: Olacel Adina , Borcea Catalin , Boromiza Marian , Dessagne Philippe , Henning Gregoire , Kerveno Maëlle , Leal Luiz , Negret Alexandru , Nyman Markus , Plompen Arjan
Published: September 2020

A 54Fe(n, n'γ) cross section measurement was performed at the Geel Electron LINear Accelerator of EC-JRC, Geel using the Gamma Array for Inelastic Neutron Scattering spectrometer and a 235U fission chamber for flux normalization. The experimental results are presented in comparison with talys 1.9 default and tuned calculations. The tuned calculation, implying modifications of the optical model parameters, improved significantly the description of the experimental values and led to interesting conclusions regarding the interaction of the 54Fe nucleus with neutrons. Since the results of these calculations were already presented extensively in a dedicated paper, the present article focuses on details related to the experimental particularities and data analysis procedure.
Neutron resonance transmission analysis of cylindrical samples used for reactivity worth measurements
Authors: Šalamon L. , Geslot B. , Heyse J. , Kopecky S. , Leconte P. , Noguere G. , Paradela C. , Schillebeeckx P. , Snoj L.
Published: September 2020

A characterisation of cylindrical samples by Neutron Resonance Transmission Analysis (NRTA) at the GELINA facility of JRC Geel (Belgium) is presented. The samples were designed and produced for reactivity worth measurements in the MINERVE reactor of CEA Cadarache (France). NRTA was applied to determine the nuclide composition of UO2, Al2O3 and liquid samples that were doped with silver. The volume number densities of 238U, 107Ag and 109Ag obtained by NRTA are within 2 % fully consistent with the values that are quoted by the manufacturer. In addition, the NRTA data reveal a tungsten contamination which is not reported by the provider. It is shown that such a contamination contributes by up to 5.7 % to the reactivity worth.
PROFIL-2 Experiment and neutron capture cross sections of Europium isotopes
Authors: Chen Shengli , Noguere Gilles , Bernard David , De Saint Jean Cyrille , Tommasi Jean
Published: September 2020

Neutron-induced cross section is one of the key quantities in nuclear physics and nuclear engineering. The integral experiment can give good feedback to the cross sections with low uncertainties. Using the optical model and statistical model, the neutron-induced total and capture cross sections of153Eu are revaluated according to the experimental microscopic total cross sections and the PROFIL-2 integral experiment. The corresponding uncertainties and covariances are determined with the data assimilation method implemented in CONRAD code. On the other hand, the previous interpretation of the PROFIL-2 experiment showed that JEFF-3.1 overestimates the neutron-induced capture cross section of 151 Eu by a factor of 2. Further analysis performed in the present work points out that the large difference between calculation and experimental data is mainly due to the lack of152m1 Eu in ERANOS code, which was used to interpret the PROFIL-2 experiment. The correction of 152m1Eu on the interpretation largely reduces the difference between JEFF-3.1 and PROFIL-2 and shows the agreement between the PROFIL-2 integral experiment and other microscopic measurements. The revaluated neutron-induced total and capture cross sections of 151 Eu and 153Eu correspond well with both the microscopic experimental measurements and the PROFIL-2 integral experiment.
Fast Neutron Capture Reaction Data Measurement of Minor Actinides for Development of Nuclear Transmutation Systems
Authors: Katabuchi Tatsuya , Iwamoto Osamu , Hori Jun-ichi , Kimura Atsushi , Iwamoto Nobuyuki , Nakamura Shoji , Shibahara Yuji , Terada Kazushi , Rovira Gerard , Matsuura Shota
Published: September 2020

A research project entitled "study on accuracy improvement of fast-neutron capture reaction data of long-lived MAs for development of nuclear transmutation systems" is ongoing as a joint collaboration, including Tokyo Tech, Japan Atomic Energy Agency and Kyoto University in Japan. This project focuses on neutron capture reaction of minor actinides237Np,241Am and243Am, in the fast neutron energy region. The final goal of this project is to improve the neutron capture cross sections utilizing a high-intensity neutron beam from a spallation neutron source of the Japan Proton Research Complex. The overview of the project and the current progress are presented.
Structure of beta-decay strength function Sβ(E) and quenching of axial-vector weak interaction constant in halo nuclei
Authors: Izosimov Igor
Published: September 2020

Resonance structure of the beta decay strength function Sβ(E) for GT β--decay of halo nuclei6He and11Li is analyzed. Compare experimental total strength for β-transitions in gv2/4π units with the Ikeda sum rule (in(gAeff)2/4πunits) one can determine the squared ratio of axial-vector and vector weak interaction constants value (geff/gV)2. We obtained(geff/gv)1= 1.272 ± 0.010 for6He and (gAeff/gv)2= 1.5±0.2 for11Li β--decays. Quenching of the weak axial-vector constantgAeffin halo nuclei is discussed. Analysis of the evolution of EGTR- EIAStoward neutron-rich nuclei was done. It is shown that the valueZ/N≈ 0.6 corresponds to the SU(4) Wigner's spin-isospin symmetry region.
Theoretical calculation and evaluation of neutron inducedreactions on Pu isotopes
Authors: Guo Hairui , Han Yinlu , Ye Tao , Sun Weili , Chen Wendi
Published: September 2020

The nuclear data on n+239,240,242,244Pu reactions for the incident energy up to 200 MeV are consistently calculated and evaluated in order to meet the design requirements of Generation-IV reactors and accelerator driven systems. The optical model, the distorted wave Born approximation theory, the Hauser-Feshbach theory, the fission model, the evaporation model, the exciton model and the intranuclear cascade model are used in the calculation, and new experimental data are taken into account. Our data are compared with experimental data and the evaluated data from JENDL-4/HE and TENDL. In addition, the variation tendency of reaction cross sections related to the target mass numbers is obtained, which is very important for the prediction of nuclear data on neutron-actinides reactions because the experimental data are lacking.
The refractive scattering of17F+12C
Authors: Hu Liyuan , Song Yushou , Hou Yingwei , Liu Huilan
Published: September 2020

The experimental data of the elastic scattering angular distribution of17F+12C at 170 MeV is analyzed by the continuum-discretized coupled channels (CDCC) method and the optical model (OM). In the CDCC calculation, the unambiguous optical potential of16O+12C is used as the input to give the coupling potentials. A very refractive feature is found and two evident Airy minima are predicted at large angles. The one-channel calculation is also performed and gives nearly the same result. In the OM calculations, this optical potential of16O+12C is used again and adjusted to reproduce the angular distribution of17F+12C. The Airy oscillation appears again in the calculated angular distribution. These results indicate that the elastic scattering of17F+12C at 170 MeV has the possibility of the nuclear rainbow phenomenon, which is probably due to the contribution from the16O core.
Microscopic optical potentials for Li isotopes
Authors: Chen Wendi , Guo Hairui , Sun Weili , Ye Tao , Han Yinlu , Shen Qingbiao
Published: September 2020

The microscopic optical potentials for Li isotopes (A=6,7) without free parameter are obtained by folding the microscopic optical potentials of their internal nucleons with density distributions generated from corresponding internal wave functions of Li isotopes. An isospin-dependent nucleon microscopic optical potential based on the Skyrme nucleon-nucleon effective interaction is used as the nucleon optical potential. Shell model is employed to construct the internal wave functions of Li isotopes and derive their density distributions of internal nucleons. The Li microscopic optical potentials are used to calculate the elastic-scattering angular distributions and reaction cross sections. The results reproduce experimental data well and are comparable to those calculated by phenomenological optical model potentials in many cases.
A new reference database for beta-delayed neutrons
Authors: Dimitriou Paraskevi , Dillmann Iris , Singh Balraj , Piksaikin Vladimir , Tain Jose-Luis , Rykaczewski Krzysztof , Algora Alejandro , Banerjee Kaushik , Borzov Ivan , Cano-Ott Daniel , Chiba Satoshi , Fallot Muriel , Foligno Daniela , Grzywacz Robert , Huang Xiaolong , Marketin Tomislav , Minato Futoshi , Mukherjee Gopal , Rasco Bertis-Charlie , Sonzogni Alejandro , Verpelli Marco
Published: September 2020

A new database containing all available experimental and evaluated β-delayed neutron data is presented in this paper. The database is the product of an international effort coordinated by the International Atomic Energy Agency. It comprises a microscopic section including all available experimental data on beta-decay half-lives, β-delayed neutron emission probabilities and spectra, as well as new systematics and global theoretical calculations for comparison. The beta-delayed neutron data for individual precursors have been benchmarked against available data on macroscopic properties such as total delayed-neutron yields and spectra, delayed-neutron decay curves and time-dependent group parameters using the summation method. All available measured macroscopic data have also been compiled in the macroscopic section of the database. The dedicated database is available online on the IAEA server (URL:http://www-nds.iaea.org/beta-delayed-neutron/database.html).
Structure of continuum states and srength function in the complex scaling method
Authors: Odsuren Myagmarjav , Khuukhenkhuu Gonchigdorj , Aiganym Sarsembayeva , Davaa Suren , Usukhbayar Batsaikhan
Published: September 2020

We present our recent results of the mirror nuclei 5He and 5Li obtained by analyzing structure of continuum states in the complex scaled α + N two-body model. Decomposed scattering cross section and continuum level density of α + N system are discussed.
Completeness of experimental fission product yields in EXFOR database
Authors: Fukuda Takanari , Okumura Shin , Otuka Naohiko
Published: September 2020

The Nuclear Reaction Data Centres (NRDC) collaborate on worldwide compilation and dissemination of experimental nuclear reaction data by developing and maintaining the EXFOR database. With the growing interests in the fission product yields of various projectiles and a wide range of energies, several evaluation activities are ongoing. In line with these activities, the IAEA conducted completeness check of fission product yield data in EXFOR against two experimental datasets developed by the ENDF and UKFY library evaluators. The present status and statistics of these datasets as well as the result of the EXFOR completeness review are presented.
Measurement of nuclide production cross section for lead and bismuth with proton in energy range from 0.4 GeV to 3.0 GeV
Authors: Matsuda Hiroki , Meigo Shin-ichiro , Iwamoto Hiroki , Maekawa Fujio
Published: September 2020

For the Accelerator-Driven nuclear transmutation System (ADS), nuclide production yield estimation in a lead-bismuth target is important to manage the target. However, experimental data of nuclide production yield by spallation and high-energy fission reactions are scarce. In order to obtain the experimental data, an experiment in J-PARC using natPb and 209Bi samples were carried out. The samples were thin foils with about 0.1 mm thick and 25 mm × 25 mm square and were irradiated with protons at kinematic energy points of 0.4GeV, 2.2GeV, and 3.0 GeV. After the irradiation, the nuclide production cross section was determined by spectroscopic measurement of decay gamma-rays from the samples with HPGe detectors. In this paper, 14 nuclide production cross sections for lead and bismuth were obtained. They were compared with the calculated cross sections with various models and the evaluated one.
γ-ray strength function for astrophysical applications in the IAEA-CRP
Authors: Utsunomiya Hiroaki , Goriely Stephane , Renstrøm Therese , Tveten Gry M. , Ari-izumi Takashi , Miyamoto Shuji , Lui Yiu-Wing , Larsen Ann-Cecilie , Siem Sunniva , Hilaire Stephane , Péru Sophie , Koning Arjan J.
Published: September 2020

Theγ-ray strength function (γSF) is a nuclear quantity that governs photoabsorption in (γ, n) and photoemission in (n, γ) reactions. Within the framework of theγ-ray strength function method, we use (γ, n) cross sections as experimental constraints on theγSF from the Hartree-Fock-Bogolyubov plus quasiparticle-random phase approximation based on the Gogny D1M interaction for E1 and M1 components. The experimentally constrainedγSF is further supplemented with the zero-limitM1 andE1 strengths to construct the downwardγSF with which (n, γ) cross sections are calculated. We investigate (n, γ) cross sections in the context of astrophysical applications over the nickel and barium isotopic chains along the s-process path.
Improved model for atomic displacement calculation
Authors: Chen Shengli , Bernard David , Tommasi Jean , De Saint Jean Cyrille
Published: September 2020

Atomic displacement is one of the key factors that influence the behaviors of material properties during and after irradiation. Many models, including the international standard metric Norgett-Robinson-Torrens model (NRT), have been developed to calculate the number of Displacement per Atom (DPA) using the energy of Primary Knocked-on Atom (PKA) as a major parameter. However, extensive experiments and simulations indicate that the NRT-DPA model seriously overestimates (about 3 times) the actual DPA. Nordlund recently developed the Athermal Recombination-Corrected DPA (ARC-DPA) model, which shows that the Molecular Dynamics (MD) simulations can be directly used to compute DPA by fitting the simulated data for each isotope. The present work proposes a simpler expression for the efficiency function to calculate the DPA without requiring fitting parameters as needed in the ARC-DPA model. Our DPA calculation results utilizing the improved efficiency function are validated against the experimental data for the Fe, Ni, Cu, and Ag. The applications in fast breeder nuclear reactors show good agreement with the ARC-DPA metric for56Fe.
Status of JENDL
Authors: Iwamoto Osamu , Iwamoto Nobuyuki , Shibata Keiichi , Ichihara Akira , Kunieda Satoshi , Minato Futoshi , Nakayama Shinsuke
Published: September 2020

Recent progress and future plan of the JENDL project are summarized. Two special purpose files were released recently. One is Photo-nuclear Data File 2016 (JENDL/PD-2016) which contains the data of photo-nuclear reaction cross sections covering a wide area of the nuclear chart. The other one is the JENDL Activation Cross Section File for Nuclear Decommissioning 2017 (JENDL/AD-2017) which provides production cross sections of radioactive nuclei by neutrons. A special purpose file JENDL/ImPACT-2018 dedicated to transmutation of long-lived fission products will be released in 2019. Regarding the general-purpose file, we are preparing to release the next version, which would be made available by 2022 as JENDL-5. Evaluation efforts on nuclides across wide range of nuclei form light to heavy have being made. The first test version JENDL-5α1 was created in 2018. The evaluated data will be updated on the basis of benchmark tests on reactor criticalities and neutron shieldings.
Completeness of neutron-, photo-induced and spontaneous fission yields data
Authors: Pritychenko B. , Schwerer O. , Totans J. , Zerkin V. , Gritzay O.
Published: September 2020

Nuclear data collection, evaluation and dissemination activities have been performed worldwide for many years. They are absolutely essential for the overall progress of science and technology to create the complete collections of experimental data sets and associated publications, and store these data in publicly accessible databases. Due to many historical and technological reasons not all published data have been identified and compiled. These "missing data" manifest themselves via scientific publications, data evaluations and nuclear databases comparisons. The detailed analysis of the Nuclear Science References (NSR) and the Experimental Nuclear Reaction (EXFOR) databases shows thousands of previously missed nuclear reaction experiments and creates a roadmap for the creation of complete data records for fission cross sections, yields and covariances. The National Nuclear Data Center (NNDC) program for identification, compilation and storage of missing fission yields data sets is described, and recommendations for improving the databases completeness are given.
Analyzing the neutron scattering angular distribution in a ACE-formatted multigroup cross section library using the maximum entropy method
Authors: ZHU Shuai-tao , MA Xu-bo , TANG Hui , YANG Le , CAO Bo
Published: September 2020

To describe the angular distribution for a group-to-group neutron scattering event, the coefficients of a truncated Legendre polynomial are usually used in the multigroup cross section. However, the truncated expansion can caused negative values of a probability density function (PDF) in some scattering angles. In this study, the PDF of scattering angles is calculated using the maximum entropy method to avoid the negative probabilities of some scattering angles and the multigroup cross section library in ACE format is generated. The multigroup cross section library is verified by the computation of RBEC-M benchmark using RMC. The differences between two methods generating scattering data, the maximum entropy method and discrete angle method, are also discussed. The calculation results using multigroup cross section library in ACE format are well good agreement with the results of benchmark report. It shows that multigroup cross section library including the scattering angle data computed by the maximum entropy method is corrected and can be used for Monte Carlo calculation.
Overview of the OECD-NEA Working Party on International Nuclear Data Evaluation Cooperation (WPEC)
Authors: Fleming M. , Bernard D. , Brown D. , Chadwick M. , de Saint Jean C. , Dupont E. , Ge Z. , Harada H. , Hawari A. , Herman M. , Iwamoto O. , Kodeli I. , Koning A. , Malvagi F. , McNabb D. , Mills R.W. , Noguère G. , Palmiotti G. , Plompen A. , Salvatores M. , Sobes V. , White M. , Yokoyama K.
Published: September 2020

The OECD Nuclear Energy Agency (NEA) Working Party on International Nuclear Data Evaluation Cooperation (WPEC) was established in 1989 to facilitate collaboration in nuclear data activities. Over its thirty year history, different Subgroups have been created to address topics in nearly every aspect of nuclear data, including: experimental measurements, evaluation, validation, model development, quality assurance of databases and the development of software tools.

WPEC has recently completed activities on fission yield evaluation, the general nuclear database structure (GNDS) to replace the ENDF-6 format, methods to provide feedback to evaluation, studies of specific capture cross sections, new methods in thermal scattering kernel evaluation and the Collaborative International Evaluated Library Organisation (CIELO) Pilot Project. Ongoing activities in GNDS application programming interface (API) development, methods for covariance evaluation and quality assurance in nuclear data validation using the International Criticality Safety Benchmark Evaluation Project (ICSBEP) database are complemented by the work of two Expert Groups that oversee the High-Priority Request List (HPRL) for Nuclear Data and the continuous development of the GNDS. New activities on the use of integral experiments for nuclear data validation and adjustment, as well as the use of the Shielding Integral Benchmark Archive and Database (SINBAD) for validation have begun and will be coordinated alongside future Subgroups.

After three decades we will review the status of WPEC, how it integrates other collections and activities organised by the NEA and how it dovetails with the initiatives of the IAEA and other bodies to effectively coordinate international activities in nuclear data.
International network of nuclear structure and decay data evaluators
Authors: Dimitriou Paraskevi , Basunia Shamsuzzoha , Bernstein Lee , Chen Jun , Elekes Zoltán , Huang Xiaolong , Hurst Aaron , Iimura Hideki , Jain Ashok Kumar , Kelley John , Kibédi Tibor , Kondev Filip , Lalkovski Stefan , McCutchan Elizabeth , Mitropolsky Ivan , Mukherjee Gopal , Negret Alexandru , Nesaraja Caroline , Nica Ninel , Pascu Sorin , Rodionov Alexander , Singh Balraj , Singh Sukhjeet , Smith Michael , Sonzogni Alejandro , Timár János , Tuli Jagdish , Verpelli Marco , Yang Dong , Zerkin Viktor
Published: September 2020

Compilation, evaluation and dissemination of nuclear data are arduous tasks that rely on contributions from experts in both the basic and applied sciences communities whose efforts are coordinated by the International Atomic Energy Agency (IAEA). The Evaluated Nuclear Structure Data File (ENSDF) includes the most extensive and comprehensive set of nuclear structure and decay data evaluations performed by the international network of Nuclear Structure and Decay Data evaluators (NSDD) under the auspices of the IAEA. In this report we describe the recent NSDD activities supported by the IAEA and provide some future perspectives.
Radioactive ion beam manipulation at the IGISOL-4 facility
Authors: Penttilä Heikki , Beliuskina Olga , Canete Laetitia , de Roubin Antoine , Eronen Tommi , Hukkanen Marjut , Kankainen Anu , Moore Iain , Nesterenko Dmitrii , Papadakis Philippos , Pohjalainen Ilkka , Reponen Mikael , Rinta-Antila Sami , Sarén Jan , Uusitalo Juha , Vilén Markus , Virtanen Ville
Published: September 2020

The IGISOL-4 facility in the JYFL Accelerator Laboratory of the University of Jyvaskyla (JYFL-ACCLAB) produces low-energy radioactive ion beams, primarily for nuclear spectroscopy, utilizing an ion guide-based, ISOL-type mass separator. Recently, new ion manipulation techniques have been introduced at the IGISOL-4 including the application of the PI-ICR (Phase-Imaging Ion Cyclotron Resonance) technique at the JYFLTRAP Penning trap, as well as commissioning of a Multi-Reflection Time-Of-Flight (MR-TOF) separator/spectrometer. The successful operation of the MR-TOF also required significant improvement of the Radio-Frequency Quadrupole (RFQ) cooler and buncher device beam pulse time structure. In addition, laser ionization techniques have been developed for particular cases, for example, a hot cavity laser ion source for silver production. A new stable isotope ion source and a beam line has been introduced for tuning and calibration purposes. In addition to the installations at the IGISOL-4 facility, the extension of the vacuum-mode recoil separator MARA (Mass Analysing Recoil Apparatus), MARA-LEB (MARA Low Energy Branch) has been under development. MARA-LEB will utilize the gas-cell technique and laser ionization to convert MeV-scale radioactive beams to low-energy ones.
NuDEX: A new nuclear γ-ray cascades generator
Authors: Mendoza E. , Cano-Ott D. , Jordan D. , Tain J.L. , Algora A.
Published: September 2020

Evaluated nuclear data libraries written in ENDF-6 format are used by Monte Carlo codes such as Geant4, MCNP6 or FLUKA for the transport of low energy neutrons (up to 20 MeV). The format in which the production of γ-rays after neutron induced reactions is provided do not allow, in general, to generate these γ-ray cascades in a correlated way. This prevents, among other things, energy conservation event by event, which is crucial in many applications. We have developed a code capable to generate correlated de-excitation γ-ray cascades using as much information as possible available in the RIPL-3 and ENSDF nuclear structure data libraries, among other useful information. The code follows the same philosophy of the DICEBOX or DEGEN codes. It generates the complete level scheme and branching ratios of the nucleus by using all the information experimentally known (known level scheme and known branching ratios) and completing the missing information with the most reliable statistical models. This code is able to generate automatically cascades for a large variety of nuclei (∼300) without requiring a specific input for each particular isotope. The code has been written in C++ language and can be integrated in the Geant4 simulation toolkit framework.
Designing Stainless Steel Reflector at VR-1 Training Reactor
Authors: Frybort Jan , Suk Pavel , Fejt Filip
Published: September 2020

Light-water reactor cores are commonly surrounded by a stainless steel and water reflector. The reflectors are improving power distribution in the core, reducing the leakage of neutrons and thus also protecting the pressurized vessel from the neutron irradiation and the following embrittlement. Contrary to the standard procedures utilized for generation of the fuel assembly data, the reflector elements require a special approach. The major difficulty with the reflectors is represented by an absence of neutron sources in the reflector elements. Some artificial neutron source simulating the realistic source of neutrons from neutron leakage from the surrounding fuel assemblies must be added in the calculation model. The reflector data in the full-core calculations have a great impact on the power distribution in the core. The research in this field is usually focused on the square geometry, and therefore the accurate data for the hexagonal geometry are lacking. Improvements in this area are needed.

Training Reactor VR-1 is used for measurements related to nuclear engineering. Department of Nuclear Reactors operating this reactor at the Czech Technical University in Prague is currently designing reflector elements containing stainless steel in order to provide measurable characteristics that can be compared to calculations realized by either Monte-Carlo codes or macroscopic core simulators. This article summarizes the methodology of development of the reflector assemblies to improve their similarity with the VVER-1000 reflector. The impact of the evaluated nuclear data is assessed. Further improvements of the proposed design is necessary to reach better agreement with the neutron spectrum in VVER-1000 reactor reflectors. The influence of evaluated data on the global characteristics was found negligible.
Introduction of a C6D6detector system on the Back-n of CSNS
Authors: Ren Jie , Ruan Xichao , Bao Jie , Luan Guangyuan , Huang Hanxiong , Nie Yangbo
Published: September 2020

Radiative neutron capture cross sections are very important in the field of basic physics research and nuclear device R&D. The Back-n white neutron beam line of China Spallation Neutron Source (CSNS) is the first spallation neutron beam line in China. On the purpose for radiative neutron capture cross section measurement, a C6D6detector system was built in the Back-n experimental station. The pulse height weighting technique (PHWT) was used to make the system’s detective efficiency independent of the cascade path and the energy of cascade gamma rays. The neutron energy spectrum was measured for the energy between 1eV and 80keV with a6Li loaded ZnS scintillation detector. Besides, a testing experiment with197Au and169Tm samples was carried out to examine this system. According to the preliminary results, this C6D6detector system can be used to perform neutron capture cross section measurement.
National Criticality Experiments Research Center (NCERC) - capabilities and recent measurements
Authors: Thompson Nicholas , Hutchinson Jesson , Bahran Rian , Hayes David , Myers William , Arthur Jennifer , Bounds John , Cutler Theresa , Dinwiddie Derek , Goda Joetta , Grove Travis , Little Robert , McKenzie George , McSpaden Alex , Sanchez Rene , Sood Avneet , White Morgan , Margevicius Robert
Published: September 2020

The National Criticality Experiments Research Center (NCERC) located at the Device Assembly Facility (DAF) at the Nevada National Security Site (NNSS) and operated by Los Alamos National Laboratory (LANL) is home to four critical assemblies which are used to support of range of missions, including nuclear criticality safety and nuclear nonproliferation. Additionally, subcritical systems can also be assembled at NCERC. NCERC is providing critical and subcritical experiments valuable to the nuclear data community and experiments performed at NCERC are often published as benchmarks in the International Criticality Safety Benchmark Evaluation Project (ICSBEP) Handbook. This manuscript will give a broad overview of recent experiments performed at NCERC, upcoming experiments, and why integral measurements are important and useful to the nuclear data community.

The four critical assemblies are GODIVA IV, FLATTOP, COMET, and PLANET. GODIVA IV is a cylindrical metal fast burst reactor, the fourth in the GODIVA series that dates back to the 1950’s. FLATTOP is an highly enriched uranium (HEU) or Pu core reflected by natural uranium. COMET and PLANET are vertical lift assemblies, where one half of the reactor can be lifted to the upper half of the reactor to create a critical system. Some recent experiments include various critical intermediate energy assemblies with lead, and subcritical measurements of plutonium reflected by copper, tungsten, and nickel. Work is also underway to make a better measurement of the critical mass of neptunium, using a neptunium sphere surrounded by nickel shells. Additionally, measurements will be performed next year with HEU shells from Rocky Flats. These HEU shells will be stacked together to make larger systems, allowing for a large range of criticality (from subcritical to delayed critical). Other upcoming measurements include an HEU critical assembly sensitive to intermediate energy neutrons.