0000000000208146

AUTHOR

Ignacio Porras

0000-0003-0754-8717

showing 6 related works from this author

New measurement of the 242Pu(n,γ) cross section at n-TOF-EAR1 for MOX fuels: Preliminary results in the RRR

2016

The spent fuel of current nuclear reactors contains fissile plutonium isotopes that can be combined with 238U to make mixed oxide (MOX) fuel. In this way the Pu from spent fuel is used in a new reactor cycle, contributing to the long-term sustainability of nuclear energy. The use of MOX fuels in thermal and fast reactors requires accurate capture and fission cross sections. For the particular case of 242Pu, the previous neutron capture cross section measurements were made in the 70’s, providing an uncertainty of about 35% in the keV region. In this context, the Nuclear Energy Agency recommends in its “High Priority Request List” and its report WPEC-26 that the capture cross section of 242Pu…

Nuclear reactionnTOFQC1-999Nuclear engineeringContext (language use)CERN nTOFNeutron[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]01 natural sciences7. Clean energyPhysics and Astronomy (all)Nuclear reactorsReactors nuclears0103 physical sciencesCERNNeutron cross sectionNuclear Physics - ExperimentNeutronddc:530242Pu neutron capture010306 general physicsMOX fuelNeutrons:Energies::Energia nuclear [Àrees temàtiques de la UPC]Fissile materialCross section:Física [Àrees temàtiques de la UPC]010308 nuclear & particles physicsPhysicsNuclear reactionSpent nuclear fuelNeutron temperature13. Climate actionneutron time-of-flight measurement
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The n_TOF facility: Neutron beams for challenging future measurements at CERN

2016

The CERN n TOF neutron beam facility is characterized by a very high instantaneous neutron flux, excellent TOF resolution at the 185 m long flight path (EAR-1), low intrinsic background and coverage of a wide range of neutron energies, from thermal to a few GeV. These characteristics provide a unique possibility to perform high-accuracy measurements of neutron-induced reaction cross-sections and angular distributions of interest for fundamental and applied Nuclear Physics. Since 2001, the n TOF Collaboration has collected a wealth of high quality nuclear data relevant for nuclear astrophysics, nuclear reactor technology, nuclear medicine, etc. The overall efficiency of the experimental prog…

AstrofísicanTOF[PHYS.PHYS.PHYS-ACC-PH]Physics [physics]/Physics [physics]/Accelerator Physics [physics.acc-ph]QC1-999Nuclear TheoryNeutronAstrophysics01 natural sciences7. Clean energylaw.inventionNuclear physicsPhysics and Astronomy (all)Neutron fluxlaw0103 physical sciencesCERNNuclear astrophysicsNeutronSpallation010306 general physicsNuclear ExperimentPhysics:Energies::Energia nuclear [Àrees temàtiques de la UPC]NeutronsLarge Hadron Collider:Física [Àrees temàtiques de la UPC]010308 nuclear & particles physicsPhysicsNuclear dataNuclear reactorNeutron radiationAccelerators and Storage Rings3. Good health13. Climate action
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New reaction rates for the destruction of $^7$Be during big bang nucleosynthesis measured at CERN/n_TOF and their implications on the cosmological li…

2019

New measurements of the7Be(n,α)4He and7Be(n,p)7Li reaction cross sections from thermal to keV neutron energies have been recently performed at CERN/n_TOF. Based on the new experimental results, astrophysical reaction rates have been derived for both reactions, including a proper evaluation of their uncertainties in the thermal energy range of interest for big bang nucleosynthesis studies. The new estimate of the7Be destruction rate, based on these new results, yields a decrease of the predicted cosmological7Li abundance insufficient to provide a viable solution to the cosmological lithium problem.

PhysicsRange (particle radiation)Large Hadron Collidern_TOF 7Be big bang nucleosynthesis cosmological lithium problem010308 nuclear & particles physicsPhysicsQC1-999chemistry.chemical_element[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]7. Clean energy01 natural sciencesReaction rateNuclear physicsBig Bang nucleosynthesischemistry13. Climate action0103 physical sciencesThermalNeutronLithiumNuclear Physics - Experiment010306 general physicsNuclear Experiment
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Be7(n,α)He4Reaction and the Cosmological Lithium Problem: Measurement of the Cross Section in a Wide Energy Range at n_TOF at CERN

2016

The energy-dependent cross section of the (7)Bed(n,alpha)He-4 reaction, of interest for the so-called cosmological lithium problem in big bang nucleosynthesis, has been measured for the first time from 10 meV to 10 keV neutron energy. The challenges posed by the short half-life of Be-7 and by the low reaction cross section have been overcome at n_TOF thanks to an unprecedented combination of the extremely high luminosity and good resolution of the neutron beam in the new experimental area (EAR2) of the n_TOF facility at CERN, the availability of a sufficient amount of chemically pure Be-7, and a specifically designed experimental setup. Coincidences between the two alpha particles have been…

Nuclear reactionPhysics010308 nuclear & particles physicsGeneral Physics and Astronomychemistry.chemical_elementAlpha particleNeutron radiation7. Clean energy01 natural sciencesNeutron temperatureNuclear physicsBig Bang nucleosynthesischemistry13. Climate actionNucleosynthesis0103 physical sciencesNeutronLithiumNuclear Experiment010306 general physicsPhysical Review Letters
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The 33S(n,α)30Si cross section measurement at n TOF-EAR2 (CERN): From 0.01 eV to the resonance region

2017

The 33S(n,α)30Si cross section measurement, using 10B(n,α) as reference, at the n TOF Experimental Area 2 (EAR2) facility at CERN is presented. Data from 0.01 eV to 100 keV are provided and, for the first time, the cross section is measured in the range from 0.01 eV to 10 keV. These data may be used for a future evaluation of the cross section because present evaluations exhibit large discrepancies. The 33S(n,α)30Si reaction is of interest in medical physics because of its possible use as a cooperative target to boron in Neutron Capture Therapy (NCT).

Nuclear reactionnTOFNeutron therapyQC1-999chemistry.chemical_elementNeutron01 natural sciencesResonance (particle physics)Nuclear physicsCross section (physics)Physics and Astronomy (all)0103 physical sciencesCERNNeutronddc:530010306 general physicsBoronPhysicsNeutrons:Energies::Energia nuclear [Àrees temàtiques de la UPC]Range (particle radiation)Large Hadron Collidercross sectionReaccions nuclears:Física [Àrees temàtiques de la UPC]010308 nuclear & particles physicsPhysicsNuclear reactionNeutron capturechemistryNuclear reactions
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Characterization and First Test of an i-TED Prototype at CERN n_TOF

2018

International audience; Neutron capture cross section measurements are of fundamental importance for the study of the slow process of neutron capture, so called s-process. This mechanism is responsible for the formation of most elements heavier than iron in the Universe. To this aim, installations and detectors have been developed, as total energy radiation C$_{6}$ D$_{6}$ detectors. However, these detectors can not distinguish between true capture gamma rays from the sample under study and neutron induced gamma rays produced in the surroundings of the setup. To improve this situation, we propose (Domingo Pardo in Nucl Instr Meth Phys Res A 825:78–86, 2016, [1]) the use of the Compton princ…

PhysicsAstrophysics::High Energy Astrophysical PhenomenaDetectorGamma rayi-TED n_TOF characterizationNeutron radiationRadiation[PHYS.NEXP]Physics [physics]/Nuclear Experiment [nucl-ex]030218 nuclear medicine & medical imagingNuclear physics03 medical and health sciencesNeutron capture0302 clinical medicineNeutron cross sectionNeutronGamma spectroscopy[PHYS.PHYS.PHYS-INS-DET]Physics [physics]/Physics [physics]/Instrumentation and Detectors [physics.ins-det]iTED n_TOF neutron
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