Study of the neutron-induced fission cross section of 237Np at CERN's n_TOF facility over a wide energy range

Neutron-induced fission cross sections of isotopes involved in the nuclear fuel cycle are vital for the design and safe operation of advanced nuclear systems. Such experimental data can also provide additional constraints for the adjustment of nuclear model parameters used in the evaluation process, resulting in the further development of fission models. In the present work, the 237Np(n,f) cross section was studied at the EAR2 vertical beam-line at CERN's n_TOF facility, over a wide range of neutron energies, from meV to MeV, using the time-of-flight technique and a set-up based on Micromegas detectors, in an attempt to provide accurate experimental data. Preliminary results in the 200 keV – 14 MeV neutron energy range as well as the experimental procedure, including a description of the facility and the data handling and analysis, will be presented.

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Preliminary results on the study of 237Np(n,f) at n_TOF/EAR2 in energies related to nuclear waste transmutation

HNPS Proceedings ◽

10.12681/hnps.2472 ◽

2020 ◽

Vol 27 ◽

pp. 18

Author(s):

Athanasios Stamatopoulos ◽

And The n_TOF Collaboration

Keyword(s):

Cross Section ◽

Fuel Cycle ◽

Evaluation Process ◽

Fission Cross Section ◽

Nuclear Model ◽

Model Parameters ◽

Preliminary Results ◽

Wide Range ◽

Nuclear Systems ◽

Induced Fission

The accurate knowledge of neutron-induced fission cross sections of isotopes involved in the nuclear fuel cycle is essential for the optimum design and safe operation of next generation nuclear systems. Such experimental data can additionally provide constraints for the adjustment of nuclear model parameters used in the evaluation process, resulting in a further understanding of the nuclear fission process. In this respect measurements of the 237Np(n,f) cross section have been performed at the n_TOF facility at CERN in the horizontal 185 m flight-path (EAR1) which were discrepant by 7% in the MeV region. The neutron-induced fission cross section of 237Np(n,f) was recently restudied at the EAR2 19.5 m vertical beam-line at CERN’s n_TOF facility, over a wide range of neutron energies, from 100 keV up to 15 MeV, using the time-of-flight technique and a modern set-up based on Micromegas detectors. This study was performed in an attempt to resolve the aforementioned discrepancies and to provide accurate data of a reaction that is frequently used as reference in measurements related to feasibility and design studies of advanced nuclear systems. Preliminary results with a high statistical accuracy that resolve the discrepancies will be presented along with a brief discussion concerning the facility and the analysis.

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The 240Pu(n,f) cross section measurement at the new experimental area at CERN's n_TOF facility

HNPS Proceedings ◽

10.12681/hnps.1857 ◽

2019 ◽

Vol 24 ◽

pp. 139

Author(s):

A. Stamatopoulos ◽

For the NTOF Collaboration

Keyword(s):

Cross Section ◽

Cross Sections ◽

Fuel Cycle ◽

Evaluation Process ◽

Nuclear Fission ◽

Nuclear Model ◽

Model Parameters ◽

Experimental Area ◽

Wide Range ◽

Nuclear Systems

The accurate knowledge of the neutron-induced fission cross-sections of actinides and other isotopes involved in the nuclear fuel cycle are essential for the design of advanced nuclear systems. These experimental data can also provide feedback for the adjustment of nuclear model parameters used in the evaluation process, resulting in further developments of nuclear fission models. In the present work, the 240Pu(n,f) cross-section was measured at CERN's n_TOF facility over a wide range of neutron energies, from a few meV to several MeV, using the time-of-flight technique and a set-up based on MicroMegas detectors. This measurement was the first experiment to be performed in n_TOF's new experimental area (EAR-2), which offers a significantly higher neutron flux compared to the existing experimental area. Preliminary results as well as the experimental procedure, including a brief description of the facility, the sample mounting, the read-out process and the data handling and analysis, are presented.

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Evaluation of Optical Model Potential Using Neutron Induced Cross Section Reaction for Spherical Uranium-238 Isotope up to 20MeV

International Letters of Chemistry Physics and Astronomy ◽

10.18052/www.scipress.com/ilcpa.59.26 ◽

2015 ◽

Vol 59 ◽

pp. 26-34

Author(s):

Iman Tarik Al-Alawy ◽

Ronak Ikram Ali

Keyword(s):

Experimental Data ◽

Energy Range ◽

Cross Section ◽

Cross Sections ◽

Optical Model ◽

Threshold Energy ◽

Model Potential ◽

Model Parameters ◽

Incident Neutron ◽

Optical Model Potential

The evaluation are based on mainly on the calculations of the nuclear optical model potential and relevant parameters are collected and selected from References Input Parameter Library (RIPL) which is being developed under the international project coordinated by the International Atomic Energy Agency (IAEA). The analyzing of a complete energy range has done starting from threshold energy for each reaction. The cross sections are reproduced in fine steps of incident neutron energy with 0.01MeV intervals with their corresponding errors. The recommended cross sections for available experimental data taken from EXFOR library have been calculated for all the considered neutron induced reactions for U-238 isotopes. The calculated results are analyzed and compared with the experimental data. The optimized optical potential model parameters give a very good agreement with the experimental data over the energy range 0.001-20MeV for neutron induced cross section reactions (n,f), (n,tot), (n,el), (n,inl), (n,2n), (n,3n), and (n,γ) for spherical U-238 target elements.

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Neutron-induced fission cross section measurement of233U,241Am and243Am in the energy range 0.5 MeV ⩽En⩽ 20 MeV at n_TOF at CERN

Physica Scripta ◽

10.1088/0031-8949/2012/t150/014005 ◽

2012 ◽

Vol T150 ◽

pp. 014005 ◽

Cited By ~ 1

Author(s):

F Belloni ◽

P M Milazzo ◽

M Calviani ◽

N Colonna ◽

P Mastinu ◽

...

Keyword(s):

Energy Range ◽

Cross Section ◽

Fission Cross Section ◽

Cross Section Measurement ◽

Section Measurement ◽

Induced Fission

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Optical Model Potential Using CINDA Library for Neutron Induced Cross Section Reactions for Spherical Uranium-235,238 Isotopes

International Letters of Chemistry Physics and Astronomy ◽

10.18052/www.scipress.com/ilcpa.60.66 ◽

2015 ◽

Vol 60 ◽

pp. 66-73

Author(s):

Iman Tarik Al-Alawy ◽

Ronak Ikram Ali

Keyword(s):

Experimental Data ◽

Energy Range ◽

Cross Section ◽

Cross Sections ◽

Optical Model ◽

Threshold Energy ◽

Model Potential ◽

Model Parameters ◽

Incident Neutron ◽

Optical Model Potential

The calculation are based mainly on the nuclear optical model potential and relevant parameters are collected and selected from References Input Parameter Library (RIPL) which is being developed under the international project coordinated by the International Atomic Energy Agency (IAEA). The analyzing of a complete energy range has done starting from threshold energy for each reaction. The cross sections are reproduced in fine steps of incident neutron energy with 0.01MeV intervals with their corresponding errors. The recommended cross sections for available experimental data taken from CINDA library have been calculated for all the considered neutron induced reactions for spherical U-235 and U-238 isotopes. The calculated results are analyzed and compared with the experimental data. The optimized optical potential model parameters give a very good agreement with the experimental data over the energy range 0.001-20MeV for neutron induced cross section reactions (n,f), (n,tot), (n,el), (n,inl), (n,2n), (n,3n), and (n,γ) for spherical U-235 and U-238 target elements.

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High-resolution evaluation of the U5(n,f) cross section from 3 keV to 30 keV

EPJ Web of Conferences ◽

10.1051/epjconf/201921102003 ◽

2019 ◽

Vol 211 ◽

pp. 02003

Author(s):

I. Duran ◽

C. Paradela ◽

M. Caamaño ◽

P. Cabanelas ◽

L. Tassan-Got ◽

...

Keyword(s):

Experimental Data ◽

High Resolution ◽

Cross Section ◽

Resonance Region ◽

Fission Cross Section ◽

Energy Calibration ◽

Fine Grid ◽

Resonance Analysis ◽

Reference File ◽

Induced Fission

235U neutron-induced fission cross-section is commonly used as reference for determining other isotope fission cross-section. However, below 150 keV this cross section is only included as Standard at the thermal point and recently its integral value between 7.8 eV and 11 eV [1]. The resolved resonance region, spanning up to 2.25 keV, has been reevaluated with high resolution in the last ENDF/B-VIII release [2] and a SAMMY resonance analysis was done by L. Leal et al. [3] including the CERN-nTOF experimental work of Paradela el al. [4] up to 10 keV, taken into account the IAEA Reference file. In this work the 235U(n,f) low-background and high-resolution experimental data obtained at the CERN-nTOF facility is combined with previous high-resolution experimental data, in order to produce a very fine grid dataset with normalisation to the IAEA Reference file. The extremelyhigh energy calibration required to reproduce the resonance sharp profiles is based on the nTOF DAQ system with a resolution below 0.1% with reference to the 8.78 eV resonance and to the sharp Al(n,g) capture dip at 5.904 keV. The comparison of the so-evaluated profile with the experimental data and with the evaluated ones will be discussed.

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