bluuebunny/crossref_metadata_2025 huggingface dataset:
Understanding the mechanism of enhanced alcoholysis of biomass carbohydrates to alkyl levulinates over bifunctional catalysts: does it resemble that in water?
Authors: Zhang Yuxuan , Ju Zhaoyang , Chen Xueli , Lyu Qian , Mei Jiaqi , Han Lujia , Liu Dong , Xiao Weihua
Published: May 2023

New insights into the origin of the enhancement in levulinate production from biomass carbohydrates over Brønsted–Lewis acid systems are reported, contributing to a better understanding of the alcoholysis mechanism.
Coupled immobilized bi-enzymatic flow reactor employing cofactor regeneration of NAD+ using a thermophilic aldehyde dehydrogenase and lactate dehydrogenase
Authors: Shortall Kim , Arshi Simin , Bendl Simon , Xiao Xinxin , Belochapkine Serguei , Demurtas Denise , Soulimane Tewfik , Magner Edmond
Published: May 2023

An immobilized bi-enzymatic (ALDHTt-LDH) flow reactor has been develeoped for the selective oxidation of aldehydes.
CH4dehydrogenation and H2formation on a Pt(100) surface: an insight from the reactive molecular dynamics simulations
Authors: Arifin Rizal , Darminto
Published: May 2023

Reactive molecular dynamics simulations revealed that the dissociation of CH4molecules on the Pt(100) surface lead to the formation of H2, CH3, C2H4, HPt, H2Pt, H3Pt, H4Pt2, H3Pt2, CH4Pt, CH5Pt, and C-chains.
Twist and measure: characterizing the effective radius of strings and bundles under twisting contraction
Authors: Hanlan Jesse M. , Davis Gabrielle E. , Durian Douglas J.
Published: May 2023

We present data for the contraction of strings and bundles under twist, for multiple materials and strand numbers. Deviation from the standard model is highlighted and improved to a degree by accounting for volume conservation and extensibility.
Controlled synthesis of Cu,Fe dual-atom catalysts restrained on metal–organic frameworks for efficient O2 activation
Authors: Xue Qi , Wun Ching Kit Tommy , Chen Tianxiang , Kawaguchi Shogo , Day Sarah , Tang Chiu , Wu Tai-Sing , Soo Yun-Liang , Lin Cong , Peng Yung-Kang , Yin Jun , Lo Tsz Woon Benedict
Published: May 2023

We present the precise synthesis of Cu,Fe DACs supported on UiO-66-NH2. The DACs show high selectivity towards benzaldehyde in photocatalytic styrene oxidation by efficient O2 activation.
A pectin-based photoactivated bactericide nanosystem for achieving an improved utilization rate, photostability and targeted delivery of hematoporphyrin
Authors: Li Yun , Cai Zhi , Yin Yihua , Yi Ying , Cai Weiquan , Tao Shengxiang , Du Mengting , Zhang Jingli , Cao Ruyu , Luo Yijing , Xu Wenjin
Published: May 2023

The bacteria-targeted PEC-HP bactericide nanosystem improved the photostability of HP, enhanced the photodynamic antibacterial activity and avoided phototoxicity to non-target organisms.
Nanozyme-integrated microneedle patch for enhanced therapy of cutaneous squamous cell carcinoma by breaking the gap between H2O2 self-supplying chemodynamic therapy and photothermal therapy
Authors: Ju Enguo , Peng Mengran , Xu Yanteng , Wang Yuqin , Zhou Feng , Wang Haixia , Li Mingqiang , Zheng Yue , Tao Yu
Published: May 2023

A microneedle patch has been developed to bridge the gap between H2O2 self-supplying chemodynamic therapy and photothermal therapy, resulting in enhanced therapy of cutaneous squamous cell carcinoma.
Design, synthesis and functionalization of BODIPY dyes: applications in dye-sensitized solar cells (DSSCs) and photodynamic therapy (PDT)
Authors: Yadav Indresh Singh , Misra Rajneesh
Published: May 2023

The present review focuses on the design, synthesis, functionalization, and application of BODIPY dyes in dye-sensitized solar cells and photodynamic therapy.
The challenge with high permittivity acceptors in organic solar cells: a case study with Y-series derivatives
Authors: Fürk Peter , Mallick Suman , Rath Thomas , Reinfelds Matiss , Wu Mingjian , Spiecker Erdmann , Simic Nikola , Haberfehlner Georg , Kothleitner Gerald , Ressel Barbara , Holler Sarah , Schaubeder Jana B. , Materna Philipp , Amenitsch Heinz , Trimmel Gregor
Published: May 2023

We synthesized high-permittivity Y-series acceptors and disclose that main reasons for the limited efficiency are others than altered bulk heterojunction morphologies.
Electrospray prepared flexible CsPbBr3 perovskite film for efficient X-ray detection
Authors: Chen Sixin , Liu Weiwei , Xu Meng , Shi Pan , Zhu Menghua
Published: May 2023

Flexible CsPbBr3 film is facilely prepared through an improved electrospraying method. Highly crystalline film and efficient X-ray detection are acquired by optimizing the solvent system and crystal growth temperature.
The impact of environmental effects on active galactic nuclei: A decline in the incidence of ionized outflows
Authors: Rodríguez Del Pino B. , Arribas S. , Chies-Santos A. L. , Lamperti I. , Perna M. , Vílchez J. M.
Published: May 2023

Active galactic nuclei (AGNs) have generally been considered to be less frequent in denser environments due to a lower number of galaxy-galaxy interactions and/or the removal of their gas-rich reservoirs by the dense intergalactic medium. However, recent observational and theoretical works suggest that the effect of ram-pressure stripping acting on galaxies in dense environments might reduce the angular momentum of their gas, causing it to infall towards the super massive black hole at their centre, activating the AGN phase. In this work we explore the connection between environment and nuclear activity by evaluating the variation in the incidence of ionized outflows, a common phenomenon associated with nuclear activity, in AGNs across different environments. We select a sample of approximately 3300 optical AGNs from the Sloan Digital Sky Survey Data Release 13, which we match with a group catalogue to identify galaxies in isolation or residing in groups. We further probe their environments through the projected distance to the central galaxy of the group or cluster and the projected surface density to the fifth neighbour (δ5). The presence of ionized outflows is determined through the modelling of the [O III] λ5007 emission line. We find that at lower masses (< 1010.3 M⊙), the fraction of ionized outflows is significantly lower in satellite AGNs (∼7%) than in isolated (∼22%) AGNs, probably due to their different AGN luminosity, L[O III], in this stellar mass range. The fraction of outflows decreases at distances closer to the central galaxy of the group or cluster for all satellite AGNs; however, only the lower-mass ones (109 − 1010.3 M⊙) display a significant decline with δ5. Although this study does not include AGNs in the densest regions of galaxy clusters, our findings suggest that AGNs in dense environments accrete less gas than those in the field, potentially due to the removal of the gas reservoirs via stripping or starvation, leading to a negative connection between environment and AGN activity. Based on our results, we propose that the observed change in the incidence of outflows when moving towards denser regions of groups and clusters could contribute to the higher gas metallicities of cluster galaxies compared to field galaxies, especially at lower masses.
Development of a small Time-Projection-Chamber for the quasi-absolute neutron flux measurement
Authors: Chatel Carole , Mathieu Ludovic , Aïche Mourad , Diakaki Maria , Bouland Olivier
Published: May 2023

Accurate actinides fission cross sections around 1 MeV are of primary importance for the safety of generation IV reactors. To have accurate measurements, the neutron flux must also be accurately estimated. This is usually done with respect to the 235U(n,f) cross section. It is however possible to measure the neutron flux with respect to the 1H(n,n)p cross section which is a primary standard, providing an independent and precise measurement. Typically, the usual proton recoil technique uses a silicon detector for neutrons of energy between 1 and 70 MeV. However, the high electron and gamma background due to neutron production under irradiation makes the use of this or any other detector not suitable for an accurate measurement below 1 MeV. To this end, the Gaseous Proton Recoil Telescope is developed and characterized. The goal is to provide quasi-absolute neutron flux measurements with an accuracy better than 3%. It consists of a double ionization chamber with a Micromegas segmented detection plane and the gaseous pressure can be adjusted to protons – and hence neutron – energy. The sensitivity to gamma and electrons background, the intrinsic efficiency as well as the resolution of this detector have been investigated.
Measurement of neutron-induced fission cross sections of 235U and 238U relative to n-p scattering at CSNS Back-n facility
Authors: Chen Yonghao , Yang Yiwei , Ren Zhizhou , Jiang Wei , Fan Ruirui , Yi Han , Liu Rong , Tang Jingyu , Jing Hantao , Li Yang , Li Qiang , Tan Zhixin
Published: May 2023

235U and 238U are very important isotopes in the nuclear energy system. Their neutron-induced fission cross sections have been measured intensively and evaluated as standard up to 200 MeV. However, as a matter of fact, the experimental data in the high-energy region are scarce. This work reports the measurement of 235, 238U(n, f) cross sections relative to n-p scattering performed at the China Spallation Neutron Source (CSNS) back-streaming neutron facility (Back-n). Preliminary results of 235, 238U(n, f) cross sections from 10 to 66 MeV are obtained, which are generally following the shape of the IAEA standard. However, significant discrepancies are observed at some given energies, which will be further studied.
On the need for precise nuclear structure data for high quality (n, n’γ) cross-section measurements
Authors: Henning Greg , Kerveno Maëlle , Dessagne Philippe , Claeys François , Dari Bako Nicolas , Dupuis Marc , Hilaire Stéphane , Romain Pascal , de Saint Jean Cyrille , Capote Roberto , Boromiza Marian , Olacel Adina , Negret Alexandru , Borcea Catalin , Plompen Arjan , Paradela Dobarro Carlos , Nyman Markus
Published: May 2023

The necessary improvement of evaluated nuclear data for nuclear applications development is possible through new and high-quality measurements, often combined with appropriate nuclear-reaction modelling. In particular, improving inelastic cross-section evaluations requires new and high-quality data. We measure (n, n’γ) cross-sections using prompt γ-ray spectroscopy and neutron energy determination by time-of-flight. To extract, from these partial data, the total inelastic cross-section, we rely on theoretical model as well as nuclear structure data such as γ ray emission probabilities. This structure information, tabulated in databases, comes with uncertainty. This directly affects the precision of our results, regardless of how good the measurement is. In this paper, we will present the issue of limited precision structure data and its impact on nuclear reaction data quality in the case of neutron inelastic scattering measurements. We will also discuss how to foresee and mitigate the issue.
Measurement of double-differential neutron yields for iron, lead, and bismuth induced by 107-MeV protons for research and development of accelerator-driven systems
Authors: Iwamoto Hiroki , Nakano Keita , Meigo Shin-ichiro , Satoh Daiki , Iwamoto Yosuke , Sugihara Kenta , Nishio Katsuhisa , Ishi Yoshihiro , Uesugi Tomonori , Kuriyama Yasutoshi , Yashima Hiroshi , Okabe Kota , Makii Hiroyuki , Hirose Kentaro , Orlandi Riccardo , Suzaki Fumi , Oizumi Akito , Tsukada Kazuaki , Maekawa Fujio , Mori Yoshiharu
Published: May 2023

For the research and development of accelerator-driven systems (ADSs) and fundamental ADS reactor physics research using the Kyoto University Critical Assembly combined with the fixed-field alternating gradient (FFAG) accelerator, we are conducting a series of experiments on double-differential neutron yields using the FFAG accelerator at Kyoto University. This paper presents an overview of the experiments together with preliminary results.
New perspectives for neutron capture measurements in the upgraded CERN-n_TOF Facility
Authors: Lerendegui-Marco J. , Casanovas A. , Alcayne V. , Aberle O. , Altieri S. , Amaducci S. , Andrzejewski J. , Babiano-Suarez V. , Bacak M. , Balibrea J. , Beltrami C. , Bennett S. , Bernardes A. P. , Berthoumieux E. , Boromiza M. , Bosnar D. , Caamaño M. , Calviño F. , Calviani M. , Cano-Ott D. , Cerutti F. , Cescutti G. , Chasapoglou S. , Chiaveri E. , Colombetti P. , Colonna N. , Console Camprini P. , Cortés G. , Cortés-Giraldo M. A. , Cosentino L. , Cristallo S. , Dellmann S. , Di Castro M. , Di Maria S. , Diakaki M. , Dietz M. , Domingo-Pardo C. , Dressler R. , Dupont E. , Durán I. , Eleme Z. , Fargier S. , Fernández B. , Fernández-Domínguez B. , Finocchiaro P. , Fiore S. , Furman V. , García-Infantes F. , Gawlik-Ramiega A. , Gervino G. , Gilardoni S. , González-Romero E. , Guerrero C. , Gunsing F. , Gustavino C. , Heyse J. , Hillman W. , Jenkins D. G. , Jericha E. , Junghans A. , Kadi Y. , Kaperoni K. , Kaur G. , Kimura A. , Knapová I. , Kokkoris M. , Kopatch Y. , Krtička M. , Kyritsis N. , Ladarescu I. , Lederer-Woods C. , Lerner G. , Manna A. , Martínez T. , Masi A. , Massimi C. , Mastinu P. , Mastromarco M. , Maugeri E. A. , Mazzone A. , Mendoza E. , Mengoni A. , Michalopoulou V. , Milazzo P. M. , Mucciola R. , Murtas† F. , Musacchio-Gonzalez E. , Musumarra A. , Negret A. , Pérez de Rada A. , Pérez-Maroto P. , Patronis N. , Pavón-Rodríguez J. A. , Pellegriti M. G. , Perkowski J. , Petrone C. , Pirovano E. , Plaza J. , Pomp S. , Porras I. , Praena J. , Quesada J. M. , Reifarth R. , Rochman D. , Romanets Y. , Rubbia C. , Sánchez A. , Sabaté-Gilarte M. , Schillebeeckx P. , Schumann D. , Sekhar A. , Smith A. G. , Sosnin N. V. , Stamati M. E. , Sturniolo A. , Tagliente G. , Tarrío D. , Torres-Sánchez P. , Urlass S. , Vagena E. , Valenta S. , Variale V. , Vaz P. , Vecchio G. , Vescovi D. , Vlachoudis V. , Vlastou R. , Wallner T. , Woods P. J. , Wright T. , Zarrella R. , Žugec P. ,   the n_TOF Collaboration
Published: May 2023

The n_TOF facility has just undergone in 2021 a major upgrade with the installation of its third generation spallation target that has been designed to optimize the performance of the two n_TOF time-of-flight lines. This contribution describes the key features and limitations for capture measurements in the two beam lines prior to the target upgrade and presents first results of (n,γ) measurements carried out as part of the commissioning of the upgraded facility. In particular, the energy resolution, a key factor for both increasing the signal-to-background ratio and obtaining accurate resonance parameters, has been clearly improved for the 20 m long vertical beam-line with the new target design while keeping the remarkably high resolution of the long beamline n_TOF-EAR1. The improvements in the n_TOF neutron beam-lines need to be accompanied by improvements in the instrumentation. A review is given on recent detector R&D projects aimed at tackling the existing challenges and further improving the capabilities of this facility.
Emissions of Hydrogen Isotopes from the Nuclear Muon Capture Reaction in natSi
Authors: Manabe Seiya , Watanabe Yukinobu , Niikura Megumi , Nakano Keita , Nakano Keita , Saito Takeshi Y. , Suzuki Daisuke , Kawashima Yoshitaka , Tomono Dai , Sato Akira , Harano Hideki
Published: May 2023

The energy spectra of protons, deuterons and tritons produced by the nuclear muon capture reaction in natSi were measured at the M1 beam line of Muon Science Innovative Channel (MuSIC) in Research Center for Nuclear Physics (RCNP) using a counter telescope consisting of a Si detector and a CsI(Tl) scintillation detector. The measured energy spectra were consistent with the previous ones. The experimental energy spectra were compared with theoretical model calculations using the Particle and Heavy Ion Transport code System (PHITS). In PHITS, both the dynamical and statistical processes in the nuclear muon capture reaction are described by the Quantum Molecular Dynamics (QMD) or the modified QMD and the Generalized Evaporation Model (GEM), respectively. The PHITS simulation reproduced generally well the measured proton spectrum at emission energies below 20 MeV, while underestimation was seen at emission energies above 20 MeV. The PHITS simulation underestimates remarkably the measured energy spectra of light complex particles (deuterons, tritons, and alpha particles) in the high energy region.
Neutron Capture and Transmission Measurements of 54Fe at the RPI LINAC
Authors: Singh Sukhjinder , Danon Yaron , Ney Adam , Cook Katelyn , Fritz Dominik , Wang Benjamin , Brain Peter , Daskalakis Adam , Rapp Michael
Published: May 2023

54Fe radiative capture cross section and transmission measurements were conducted at the Rensselaer Polytechnic Institute (RPI) Gaerttner Linear Accelerator (LINAC) Center using an enriched 54Fe sample in the keV energy region. 54Fe is a constituent of natural iron, which is present in a large variety of nuclear grade materials. Therefore, it is important to have an accurate understanding of the cross sections of 54Fe, which can be measured experimentally. In the time-of-flight measurements conducted at the LINAC, an array of four C6D6 detectors surrounded the sample and radiative capture data were collected using a digital data acquisition system. Additionally, a Li-glass detector was used to collect transmission data using an analog data acquisition system. The radiative capture yield of the 54Fe measurements were normalized to saturated resonances observed in Au and Ta to obtain an absolute capture yield. The preliminary capture yield and preliminary transmission obtained can be compared to evaluations and existing experimental data. Some disagreements were observed in prominent d-wave capture resonances observed in 54Fe in the low-keV neutron energy region. Both sets of experimental data along with pre-existing datasets will greatly enhance RPI’s ability to perform resonance evaluation for 54Fe up to roughly 1 MeV.
Study of decay properties of Ba to Nd nuclei (A~160) relevant to the formation of the r-process rare-earth peak
Authors: Pallàs M. , Tarifeño-Saldivia A. , Kiss G. G. , Tain J. L. , Tolosa-Delgado A. , Vitéz-Sveiczer A. , Calviño F. , Agramunt J. , Aguilera P. , Algora A. , Allmond J. M. , Baba H. , Brewer N. T. , Caballero-Folch R. , Coleman-Smith P. J. , Cortes G. , Davinson T. , Dillmann I. , Domingo-Pardo C. , Estrade A. , Fukuda N. , Go S. , Griffin C. J. , Grzywacz R. K. , Hall O. , Harkness-Brennan L. J. , Isobe T. , Kahl D. , King T. T. , Korgul A. , Kovács S. , Kubono S. , Labiche M. , Liu J. , Madurga M. , Miernik K. , Molina F. , Mont-Geli N. , Morales A. I. , Nácher E. , Navarro A. , Nepal N. , Nishimura S. , Piersa-Silkowska M. , Phong V. , Rasco B. C. , Romero-Barrientos J. , Rubio B. , Rykaczewski K. P. , Saito Y. , Sakurai H. , Shimizu Y. , Singh M. , Sumikama T. , Suzuki H. , Szegedi T. N. , Takeda H. , Wang K. , Wolińska-Cichocka M. , Woods P. J. , Yokoyama R. ,   for the BRIKEN collaboration
Published: May 2023

Half-lifes (T1/2) of exotic neutron-rich isotopes of Ba, La, Ce, Pr, and Nd were measured at the RIKEN Nishina Center. The experimental setup consisted of the BigRIPS in-flight separator for ion selection identification, the Advance Implantation Detector Array (AIDA) for ions and β detection, and the BRIKEN detector for neutron counting. Using this setup, 4 new T1/2 have been measured for the first time, and 38 T1/2 have been remeasured with improved precision in several cases. These new experimental data should help to constrain theoretical models for calculations of T1/2. The status of the experimental analysis and preliminary results are provided in this contribution.
Importance of the residual nucleus level density in the calculation of the 239Pu(n, 2n)238Pu excitation function
Authors: Bouland Olivier , Méot Vincent , Roig Olivier
Published: May 2023

In parallel with the recent measurement by Méot et al. [1] of the 239Pu(n, 2n)238Pu reaction cross section in the [7-10] MeV neutron-incident energy range, a modeling work was undertaken to support the new measurement. This theoretical framework is here dedicated to study the impact of the type of level density for the 239Pu residual nucleus (RN) on the final shape of the low-energy tail of the (n, 2n) excitation function. For this purpose, the AVXSF-LNG program [4] has been upgraded to model second-chance reactions and coupled to the TALYS-ECIS06 nuclear reaction codes [3] that are used to provide the compound nucleus (CN) cross section to AVXSF-LNG as a function of the selected pre-equilibrium model . The spin-dependent population of the RN obtained after CN emission is commonly advertised when using an exciton-based model for calculating the total pre-equilibrium cross section. On the other hand a population based on a particle-hole state density is rather expected when using the MSD/MSC quantum mechanical description in place of the exciton-based model. As far as a spectrum of a few number of individual excitations is favored, the combinatorial Quasi-Particle-Vibrational-Rotational Level Density method [4] implemented in the AVXSF-LNG computer program is well suited to model the various alternatives. Several RN level densities have been tested in this work. It includes the testing of the Quasi-particle Random Phase Approximation-based result of Ref. [6]. As a guide line, the amount of pre-equilibrium flux in the total (n,2n) excitation function is being studied as a function of the type of level density selected for the residual nucleus.
Preequilibrium models for 58Ni (n, xp) reaction in Neutrons at 8, 9, 9.4, 11 and 14.8 MeV using the EMPIRE and TALYS codes
Authors: Yettou Leila , Belgaid Mohamed
Published: May 2023

In this study, the calculations of proton emission spectra produced by 58Ni (n, xp) reaction are used in the framework of preequilibrium models with the EMPIRE and TALYS codes. Exciton Model predictions combined with the Kalbach angular distributions systematics and statistical Multi-step Direct (MSD) with Multi-step Compound (MSC) processes preequilibrium models were used. Also, some necessary parameters as optical model, level density, level density a-parameter and single-particle level density parameter have been investigated for our calculations. The comparison with experimental data shows clear improvement over the Exciton and MSD with MSC models calculations.
Determination of the Plasma Delay Time in PIPS detectors for fission fragments at the LOHENGRIN spectrometer
Authors: Gómez Ana M. , Al-Adili Ali , Göök Alf , Pomp Stephan , Pousette André , Solders Andreas , Tarrío Diego , Gao Zhihao , Köster Ulli , Kim Yung Hee , Smith A. Gavin , Sosnin Nikolay V. , Bennett Samuel , Wright Tobias , Oberstedt Andreas , Oberstedt Stephan
Published: May 2023

The VElocity foR Direct particle Identification spectrometer (VERDI) is a 2E-2v fission spectrometer that allows the measurement of the total mass distribution of secondary fission fragments with a resolving power of 1-2 u. It consists of two time-of-flight (ToF) arms, with one Micro Channel Plate (MCP) detector and up to 32 Silicon PIPS (Passive Implanted Planar Silicon) detectors per arm. The MCPs provide the start timing signals and the PIPS detectors provide both the energy and the stopping ToF signals. In real conditions, the PIPS signals are affected by the formation of plasma from the interaction between the heavy ions and the detector material. The plasma contributes to a reduction in signal amplitude, resulting in a Pulse Height Defect (PHD), and introduces a signal delay, known as Plasma Delay Time (PDT). An experiment to characterize the PDT and PHD was performed at the LOHENGRIN recoil separator of the Institut Laue Langevin (ILL). Characteristic fission fragments from the 239Pu(n,f) reaction were separated based on their A/Q and E/Q ratios, allowing the measurement of a wide range of energies from 21 to 110 MeV and masses between 80 and 149 u. Six PIPS detectors were characterized to study their individual responses to the PDT and PHD effects. The signals were recorded in a digital acquisition system to completely exploit the offline analysis capabilities. Achieved combined timing and energy resolutions for fission fragments varied between 72(2) ps and 100(4) ps and 1.4% - 2% (FWHM), respectively. Preliminary PHD and PDT data are presented from the masses A=85, 95, 130 and 143. The PHD trends are strongly correlated with both the ion energy and mass. The PDT, on the other hand, shows a strong variation as a function of the ion kinetic energy but a smaller dependence on the ion mass.
Detector set up for the measurements of the neutron-induced fission cross section of 235U relative to n-p scattering up to 150 MeV at CERN-n_TOF
Authors: Pirovano E. , Manna A. , Colonna N. , Console Camprini P. , Cosentino L. , Dietz M. , Ducasse Q. , Finocchiaro P. , Massimi C. , Mengoni A. , Nolte R. , Radeck D. , Tassan-Got L. , Terranova N. , Ventura A. , Aberle O. , Alcayne V. , Amaducci S. , Andrzejewski J. , Audouin L. , Babiano-Suarez V. , Bacak M. , Barbagallo M. , Bennett S. , Berthoumieux E. , Billowes J. , Bosnar D. , Brown A. , Busso M. , Caamaño M. , Caballero-Ontanaya L. , Calviño F. , Calviani M. , Cano-Ott D. , Casanovas A. , Cerutti F. , Chiaveri E. , Cortés G. , Cortés-Giraldo M. A. , Cristallo S. , Damone L. A. , Davies P. J. , Diakaki M. , Domingo-Pardo C. , Dressler R. , Dupont E. , Durán I. , Eleme Z. , Fernández-Domínguez B. , Ferrari A. , Göbel K. , Garg R. , Gawlik-Ramie˛ga A. , Gilardoni S. , Gonçalves I. F. , González-Romero E. , Guerrero C. , Gunsing F. , Harada H. , Heinitz S. , Heyse J. , Jenkins D. G. , Junghans A. , Käppeler† F. , Kadi Y. , Kimura A. , Knapová I. , Kokkoris M. , Krtička M. , Kurtulgil D. , Ladarescu I. , Lederer-Woods C. , Leeb H. , Lerendegui-Marco J. , Lonsdale S. J. , Macina D. , Martínez T. , Masi A. , Mastinu P. , Mastromarco M. , Maugeri E. A. , Mazzone A. , Mendoza E. , Michalopoulou V. , Milazzo P. M. , Mingrone F. , Moreno-Soto J. , Musumarra A. , Negret A. , Ogállar F. , Oprea A. , Patronis N. , Pavlik A. , Perkowski J. , Piersanti L. , Petrone C. , Porras I. , Praena J. , Quesada J. M. , Ramos-Doval D. , Rauscher T. , Reifarth R. , Rochman D. , Rubbia C. , Sabaté-Gilarte M. , Saxena A. , Schillebeeckx P. , Schumann D. , Sekhar A. , Smith A. G. , Sosnin N. V. , Sprung P. , Stamatopoulos A. , Tagliente G. , Tain J. L. , Tarifeño-Saldivia A. , Thomas Th. , Torres-Sánchez P. , Tsinganis A. , Ulrich J. , Urlass S. , Valenta S. , Vannini G. , Variale V. , Vaz P. , Vescovi D. , Vlachoudis V. , Vlastou R. , Wallner A. , Woods P. J. , Wright T. , Žugec P.
Published: May 2023

A new measurement of the 235U(n,f) fission cross section was carried out at n_TOF. The experiment covered the neutron energy range from 10 MeV up to 500 MeV, and it used the 1H(n,n) cross section as normalization for the neutron fluence measurement. In this contribution, the measurements and the characterization of the detectors covering the incident energy range up to 150 MeV are discussed.
Comprehensive investigation of ﬁssion yields by using spallation- and (p,2p)- induced ﬁssion reactions in inverse kinematics
Authors: Rodríguez-Sánchez J. L. , Graña-González A. , Benlliure J. , Chatillon A. , García-Jiménez G. , Taïeb J. , Alvarez-Pol H. , Atar L. , Audouin L. , Authelet G. , Besteiro A. , Blanchon G. , Boretzky K. , Cabanelas P. , Casarejos E. , Cederkall J. , Cortina-Gil D. , Corsi A. , De Filippo E. , Feijoo M. , Galaviz D. , Gasparic I. , Gernhäuser R. , Haettner E. , Heil M. , Heinz A. , Holl M. , Jenegger T. , Ji L. , Johansson H. T. , Kelić-Heil A. , Kiselev O. A. , Klenze P. , Knyazev A. , Körper D. , Kröll T. , Lihtar I. , Litvinov Y. A. , Löher B. , Martorana N. , Morfouace P. , Mücher D. , Murillo Morales S. , Obertelli A. , Panin V. , Park J. , Paschalis S. , Perea A. , Petri M. , Pietri S. , Pirrone S. , Ponnath L. , Revel A. , Rhee H.-B. , Rose L. , Rossi D. M. , Russotto P. , Simon H. , Stott A. , Sun Y. , Sürder C. , Taniuchi R. , Tengblad O. , Törnqvist H. T. , Trimarchi M. , Velardita S. , Vesic J. , Voss B. , Weick H. ,   the R
Published: May 2023

In the last decades, measurements of spallation, fragmentation and Coulex induced ﬁssion reactions in inverse kinematics have provided valuable data to accurately investigate the ﬁssion dynamics and nuclear structure at large deformations of a large variety of stable and non-stable heavy nuclei. To go a step further, we propose now to induce ﬁssion by the use of quasi-free (p,2p) scattering reactions in inverse kinematics, which allows us to reconstruct the excitation energy of the compound ﬁssioning system by using the four-momenta of the two outgoing protons. Therefore, this new approach might permit to correlate the excitation energy with the charge and mass distributions of the ﬁssion fragments and with the ﬁssion probabilities, given for the ﬁrst time direct access to the simultaneous measurement of the ﬁssion yield dependence on temperature and ﬁssion barrier heights of exotic heavy nuclei, respectively. The ﬁrst experiment based on this methodology was realized recently at the GSI/FAIR facility and a detailed description of the experimental setup is given here.
Charged particle induced reactions on beryllium as a fast neutron source for irradiation experiments
Authors: Stefanik Milan , Simeckova Eva , Kozic Jan , Ansorge Martin , Majerle Mitja , Mrazek Jaromir , Novak Jan
Published: May 2023

Nuclear Physics Institute of the Czech Academy of Sciences (NPI CAS) in Rez operates the compact accelerator-driven NG-2 fast neutron source. The NG-2 neutron source uses proton (up to 35 MeV) and deuteron (up to 20 MeV) beams extracted from the isochronous cyclotron U-120M and beryllium target station for broad neutron spectrum production and lithium target station for quasi-monoenergetic neutron field production (the p+Li(C) reaction on thin target). These sources are primarily focused on nuclear data measurement and validation, especially for the future fusion energetics (DEMO and IFMIF-DONES research programs). To extend their experimental utilization mostly towards some more traditional research reactor applications (such as the neutron activation analysis and material research), the neutron fields generated by the p+Be and d+Be source reactions for various energies of charged particle beams provided by the U-120M cyclotron have been recently studied using the multi-foil activation technique. New neutron fields based on the p(35 MeV)+Be, p(30 MeV)+Be, p(24 MeV)+Be, and p(20 MeV)+Be source reactions as well as the d(20 MeV)+Be, d(15 MeV)+Be, and d(10 MeV)+Be reactions are available at NPI CAS now.
Beta spectrum shape studies for the predictions of the antineutrino spectrum from reactors
Authors: Alcalá G. A. , Algora A. , Fallot M. , Estienne M. , Guadilla V. , Gelletly W. , Beloeuvre A. , Stutzmann J.-S. , Bouvier S. , Eronen T. , Agramunt J. , Bonnet E. , Etasse D. , Giot L. , Laureau A. , Porta A. , Victoria J. A. , Molla Y. ,   the IGISOL collaboration
Published: May 2023

Nuclear reactors antineutrino measurements at short baselines do not fully agree with model predictions calculated with the Conversion Method. An alternative method to calculate the antineutrino spectra is theSummation Method. Both methods require the shapes of beta spectra as inputs. For that reason a new setup to measure the shape of the beta spectrum of relevant fission products for the calculation of the antineutrino spectra of reactors has been developed. Some preliminary measurements performed at IGISOL with isotopically clean beams are presented in this contribution.
From fission yield measurements to evaluation: Propositions of 235U(nth,f) Fission Yields for JEFF-4
Authors: Cheikh Sidi-Mohamed , Kessedjian Grégoire , Serot Olivier , Chebboubi Abdelhazize , Mills Robert , Vallet Vanessa , Bernard David , Capponi Luigi
Published: May 2023

The study of fission yields has a major impact on the characterization and understanding of the fission process and its applications. The fission products have a direct influence on the amount of neutron poisons that limit the fuel burnup and on the evaluation of the decay heat of the reactor after shutdown. Fission yield evaluation represents the synthesis of experimental and theoretical knowledge in order to perform the best estimation of mass and independent fission product yields. Today, the lack of correlations between the different fission observables induces some inconsistencies in the evaluations. For instance, the mass yield uncertainties are drastically overestimated while this observable is the best known. In this last decade, different covariance matrices have been proposed but the experimental part of those are neglected. A consistent covariance matrix depends on the global process of evaluation from data up to the models used. The collaboration develops a new methodology in the field of fission products for the future version of the JEFF-library coupling the analyses of the CEA and NNL institutes.
Measurement of the fission yield of 136Cs in the 239Pu(nth,f) reaction
Authors: Chebboubi Abdelaziz , Bernard David , Vallet Vanessa , Kessedjian Grégoire , Méplan Olivier , Kim Yung Hee , Köster Ulli , Géhin Florian , Sage Christophe , Ramdhane Mourad , Houdouin-Quenault Maxime , Düllmann Christoph E. , Mokry Christoph , Runke Jörg , Renisch Dennis , Litaize Olivier , Serot Olivier
Published: May 2023

A recent experimental campaign performed at the LOHENGRIN spectrometer at ILL aimed at measuring the independent fission yield of 136Cs in the 239Pu(nth,f) reaction. This nuclide can have an important contribution to the total dose rate coming from spent light water reactor UOX and MOX fuels. Moreover, its impact is of first order on the uncertainty of the total dose rate calculated in specific areas of Nuclear Power Plants within accidental conditions. One of the most important sources of uncertainty is its independent fission yield. Therefore, a new measurement of its independent yield along with a rigorous uncertainty analysis was performed. Due to its low independent yield, a new measurement technique has been applied. Ions recoiling from neutron-irradiated 239Pu target were collected by implantation into an Al foil placed inside a vacuum chamber. This foil was then transferred to a low γ-ray background setup located at nearby laboratory (LPSC). The procedure was then repeated for different LOHENGRIN settings. Compared to the JEFF-3.1.1 library, a decrease of the fission yield of 136Cs with a reduced uncertainty is obtained.
Determination of positron emission intensity in the decay of 86gY
Authors: Uddin M. Shuza , Basunia M. Shamsuzzoha , Bernstein Lee A. , Spahn Ingo , Scholten Bernhard , Neumaier Bernd , Qaim Syed M.
Published: May 2023

The β+- emitting radionuclide 86gY (t1/2 = 14.7 h) forms a matched-pair with the β--emitting therapeutic radionuclide 90Y (t1/2 = 2.7 d) for theranostic application in medicine. Precise knowledge of the positron emission probability of the PET nuclide is very important, which was rather uncertain for 86gY until recently. In this work, an 86gY source of high radionuclidic purity was prepared and the positron emission intensity per 100 decay of the parent (hereafter “positron emission intensity”) was determined by measuring the 511 keV annihilation γ-ray using high-resolution HPGe detector. The total source activity was obtained from known γ-ray emission probabilities. The electron capture (EC) intensity was also determined as an additional check by measuring the Kα and Kβ X-rays of energies 14.1 and 15.8 keV, respectively, using a low energy HPGe detector. From those measurements, normalized values of 27.2 ± 2.0% for β+ -emission and 72.8 ± 2.0% for EC were deduced. These results are in excellent agreement with values recently reported in the literature based on a detailed decay scheme study.
Evaluation of delayed neutron yields and time spectra from photofission of 238U induced by Bremsstrahlung photons below 9 MeV
Authors: Sari Adrien , Elayeb Aly , De Stefano Roberto , Meleshenkovskii Iaroslav , Michel Maugan , Carrel Frédérick
Published: May 2023

Few data exist regarding the yields and time spectra of delayed neutrons from the photofission reaction on actinides. In this paper, we report the characteristics of both six-group and eight-group delayed neutron time models for the photofission of 238U induced by a Bremsstrahlung photon spectrum with an end-point energy at 9 MeV. This study was conducted using a 9 MeV linear electron accelerator housed at the SAPHIR platform located at CEA Paris-Saclay, France. A reference sample of depleted uranium was positioned inside a neutron detection block, previously designed and optimized by Monte Carlo simulation, made of high-density polyethylene covered by cadmium and including ten one meter-long 3He proportional counters. Based on the consistent set of half-lives proposed by Spriggs et al. as early as 1999 for neutroninduced fission, our description in eight delayed neutron groups for 238U at 9 MeV is the first published for photofission. These new results bring valuable information to the scarce data available in the literature and represent useful inputs for the development of photofission-based nuclear measurement systems as they meet a significant interest in the fields of nuclear data, radioactive waste package characterization and for security-related applications.
Expanded COG criticality validation suite for inter-laboratory benchmark data comparison
Authors: Heinrichs David , Kim Soon , McKinley Scott
Published: May 2023

The COG suite of criticality benchmarks has been formally expanded from 591 to 3,395 to coverthe entire energy range from thermal to fast neutron spectra under a variety of reflector and moderator conditions and fissile materials. COG results have been compared with benchmark values from the International Criticality Safety Benchmark Evaluation Project Handbook for ENDF/B-VII.1, ENDF/BVIII.0 and JEFF-3.3. COG results have been also compared with a MERCURY validation suite. Most of the results agreed with the benchmark values within ±3σ. Among the three cross section data, cases with ENDF/B-VIII.0 performed best with about 85% of the total cases within ±3σ range. A major intercomparison project between COG, MCNP, MORET, and SCALE for ENDF/B-VIII.0 and JEFF-3.3 is in progress.
Bayesian Monte Carlo Evaluation of Imperfect (n, 233U) Data and Model
Authors: Brown Jesse M. , Arbanas Goran , Wiarda Dorothea , Guber Klaus H. , Holcomb Andrew , Sobes Vladimir
Published: May 2023

Conventional nuclear data evaluation methods using generalized linear least squares make the following assumptions: prior and posterior probability distribution functions (PDFs) of all model parameters and data are normal (Gaussian); the linear approximation is sufficiently accurate to minimize the cost function (even for nonlinear models); the model (e.g., of neutron cross section) and experimental data (including covariance data) are without defect and prior PDFs of parameters and measured data are known perfectly. Neglect of covariance between model parameters and measured data in conventional evaluations contributes to imperfections. These assumptions are inherent to the generalized linear least squares minimization method commonly used for resolved resonance region neutron cross section evaluations but are often not justified due to the presence of non-normal PDFs, nonlinear models (e.g., R-matrix formalism), and inherent imperfections in data and models (e.g. imperfect covariance data). Here, these assumptions are removed in a mathematical framework of Bayes’ theorem, which is implemented using the Metropolis-Hastings Monte Carlo method. Most importantly, new parameters are introduced to parameterize discrepancies between the theoretical model and measured data to quantify judgement about discrepancies or imperfections in a reproducible manner. An evaluation of 233U in the eV region using the ENDF-B/VIII.0 library and transmission data (Guber et al.) is presented, and posterior parameters are compared to those obtained by conventional evaluation methods. This example illustrates the effects of removing the most harmful assumption: that of model-data perfection.
Uncertainty Considerations that Impact the Use of Dosimetry Metrics in Modern Semiconductors
Authors: Griffin Patrick
Published: May 2023

The use of calculated dosimetry metrics is a crucial element in predicting neutron damage to modern semiconductors under various conditions, e.g., control electronics in avionic systems, satellite sensors, or power output from solar panels. These dosimetry metrics have little value unless they are accompanied by a quantified uncertainty. This paper outlines a mathematical framework that captures the response models for most semiconductor damage metrics and addresses some of the challenges faced in quantifying the relevant sources of uncertainty. The energy-dependent correlations in the damage functions are a critical underpinning in propagating the uncertainty back to a measured quantity. Significant issues are associated with “model defect” in some of the models used, i.e., assumptions in the model form that are not easily considered in the uncertainty estimate. Other issues relate to fundamental differences between the experimental measured quantity and the calculated metric used to represent the damage mode.
A Study of the Covariance Data in ENDF/B VIII.0 for Low Z Isotopes
Authors: Parsons D. Kent
Published: May 2023

Thirty group covariance data have been produced from ENDF/B VIII.0 MF 33 for H1, H2, He4, Li6, Li7, Be9, B10, B11, C12, C13, N15, O16, the JENDL O16 and F19. Multi-group cross section covariance data was produced by NJOY routine ERRORR. Negative eigenvalues were found only for F19, but the covariance constraints required for the condition of the sum of partial cross sections being equal to the resultant total cross section were found to be incorrect for H2, Li6, B10, C12, C13, and O16. An easy correction is suggested for Li6 and C13. An expansion of the ENDF-6 formats manual is suggested for the MF 33 chapter and a new proposed covariance normalization scheme is proposed.
Resolved resonance region analysis of 206Pb, 207Pb, and 208Pb for next generation lead-cooled fast systems
Authors: Brain Peter , Danon Yaron , Brown Dave , Barry Devin
Published: May 2023

Recently, great interest has been generated in using lead as a coolant for fast neutron sys tems and as a result it is important to investigate the ENDF/B-VIII.0 [6] isotopic evaluations that comprise stable le ad. To this end, resonance parameters for 206Pb, 207Pb, and 208Pb were re-evaluated because their resolved reso­ nance regions extend beyond 0.5 MeV meaning resonance parameters used in reconstructing cross sections and elastic scattering angular distributions impact fast systems. The impact of resonance parameters is demon­ strated by the differences between the evaluations in predicting experimental results from the fully modeled RPI Quasi-Differential Scattering Experiment[lO] via MCNPv6.2 [12]. In addition , MCNP KCODE calculations of lead-sensitive fast spectra critical benchmarks showed variations of keff on average of 400 pcm, caused solely from differences in elastic scattering angular distributions in 208Pb. Re-evaluation entailed fitting data with the program SAMMY[l8].
Database work for the new cross section standards evaluation
Authors: Carlson Allan , Capote Roberto , Neudecker Denise , Pronyaev Vladimir , Schnabel Georg
Published: May 2023

An effort is now underway to produce a new evaluation of the neutron standards. It is important to maintain experimental programs to increase the quality and extend the database for the neutron cross section standards in order to improve evaluations of them that will be used to convert cross section measurements made relative to those standards. Measurements have been made for most of the standard cross sections since the last evaluation of the standards. The improved database includes the cross sections for the H(n,n), 6Li(n,t), 10B(n,αγ), 10B(n,α), C(n,n), Au(n,γ), 235U(n,f) and 238U(n,f) standard reactions and ratios among them. The database also includes the 238U(n,γ) and 239Pu(n,f) cross sectionsin addition to the standard cross sections. Those data were included since there are many ratio measurements of those cross sections with the standards and absolute data are available for them.
New setup for measurement of prompt gammas from neutron interactions
Authors: Czakoj Tomáš , Košťál Michal , Losa Evžen , Šimon Jan , Matěj Zdeněk , Mravec Filip , Cvachovec František , Novák Evžen
Published: May 2023

Prompt gamma radiation from neutron interactions is an important issue as it affects the operation of nuclear facilities (radiation protection or gamma heating issues) or has various uses (non-destructive identification of elements). Despite of importance, its production is inaccurately described in present nuclear data libraries. Therefore, a set of experiments have been carried out focusing on this radiation - prompt gamma from neutron inelastic scattering on oxygen and prompt gamma from radiative capture on manganese, both present the form of an aqueous solution. The gammas were induced by the Am-Be neutron source (for oxygen) and 252Cf spontaneous fission neutron source (for manganese). In the case of oxygen, the present libraries can be used, but all the libraries tested overestimated the experiment by 20–30%, considering the experimental uncertainty of 6-9%. INDEN-4.0 library is giving the best results. In the case of manganese, none of the libraries tested give acceptable results. The INDEN updated data for gamma production on manganese give usable results, but there is still a discrepancy from -36% to 55% with uncertainties from 6-15%.
EUCLID: A New Approach to Constrain Nuclear Data via Optimized Validation Experiments using Machine Learning
Authors: Hutchinson J. , Alwin J. , Clark A.R. , Cutler T. , Grosskopf M.J. , Haeck W. , Herman M.W. , Kleedtke N. , Lamproe J. , Little R.C. , Michaud I.J. , Neudecker D. , Rising M.E. , Smith T. , Thompson N. , Vander Wiel S. , Wynne N.
Published: May 2023

Compensating errors between several nuclear data observables in a library can adversely impact application simulations. The EUCLID project (Experiments Underpinned by Computational Learning for Improvements in Nuclear Data) set out to first identify where compensating errors could be hiding in our libraries, and then design validation experiments optimized to reduce compensating errors for a chosen set of nuclear data. Adjustment of nuclear data will be performed to assess whether the new experimental data—spanning measurements from multiple responses—successfully reduced compensating errors. The specific target nuclear data for EUCLID are 239Pu fission, inelastic scattering, elastic scattering, capture, nu-bar, and prompt fission neutron spectrum (PFNS). A new experiment has been designed, which will be performed at the National Criticality Experiments Research Center (NCERC).