A5018759764- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Nuclear physics research studies
- Radiation Detection and Scintillator Technologies
- Atomic and Subatomic Physics Research
- Nuclear Materials and Properties
- Advanced NMR Techniques and Applications
- Muon and positron interactions and applications
- Particle Detector Development and Performance
- Astro and Planetary Science
- Radiation Therapy and Dosimetry
- Atomic and Molecular Physics
- Astronomical and nuclear sciences
- Superconducting Materials and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Particle physics theoretical and experimental studies
- Advanced Chemical Physics Studies
- Quantum Chromodynamics and Particle Interactions
- Ammonia Synthesis and Nitrogen Reduction
- High-Energy Particle Collisions Research
- Fusion materials and technologies
- Particle accelerators and beam dynamics
- Gamma-ray bursts and supernovae
- Graphene research and applications
- Copper Interconnects and Reliability
Charles University
2015-2024
Goethe University Frankfurt
2019-2023
Medisch Centrum Alkmaar
2022
International Atomic Energy Agency
2009-2022
CEA Paris-Saclay
2009-2020
Commissariat à l'Énergie Atomique et aux Énergies Alternatives
2009-2020
European Organization for Nuclear Research
2020
Université Paris-Saclay
2020
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud
2016-2017
Triangle Universities Nuclear Laboratory
2008-2011
The neutron time-of-flight facility n_TOF features a white source produced by spallation through 20GeV/c protons impinging on lead target. facility, aiming primarily at the measurement of neutron-induced reaction cross sections, was operating CERN between 2001 and 2004, then underwent major upgrade in 2008. This paper presents detail all characteristics new beam currently available configurations, which correspond to two different collimation systems choices moderator. discussed include...
The energy-dependent cross section of the ^{7}Be(n,α)^{4}He reaction, interest for so-called cosmological lithium problem in big bang nucleosynthesis, has been measured first time from 10 meV to keV neutron energy. challenges posed by short half-life ^{7}Be and low reaction have overcome at n_TOF thanks an unprecedented combination extremely high luminosity good resolution beam new experimental area (EAR2) facility CERN, availability a sufficient amount chemically pure ^{7}Be, specifically...
At the neutron time-of-flight facility n_TOF at CERN a new vertical beam line was constructed in 2014, order to extend experimental possibilities this an even wider range of challenging cross-section measurements interest astrophysics, nuclear technology and medical physics. The design hall based on FLUKA Monte Carlo simulations, aiming maximizing flux, reducing halo minimizing background from neutrons interacting with collimator or back-scattered dump. present paper gives overview relevant...
We report on the measurement of ^{7}Be(n,p)^{7}Li cross section from thermal to approximately 325 keV neutron energy, performed in high-flux experimental area (EAR2) n_TOF facility at CERN. This reaction plays a key role lithium yield big bang nucleosynthesis (BBN) for standard cosmology. The only two previous time-of-flight measurements this did not cover energy window interest BBN, and they showed large discrepancy between each other. was with Si telescope high-purity sample produced by...
Thermal stability of ultrafine grained (mean grain size 150 nm) copper prepared by high pressure torsion was studied means positron-lifetime spectroscopy correlated with transmission electron microscopy. The microstructure the material is strongly inhomogeneous. interiors low dislocation density are separated distorted regions number dislocations. We have found that positrons trapped at dislocations inside and in microvoids situated grains. Calculations lifetime a positron microvoid as...
A high-resolution measurement of the neutron-induced fission cross section $^{234}\mathrm{U}$ and $^{237}\mathrm{Np}$ has been performed at CERN Neutron Time-of-Flight facility. The sections have determined in a wide energy range from 1 eV to GeV using evaluated $^{235}\mathrm{U}$ as reference. In these measurements determination for resonances could be improved, whereas previous discrepancies were confirmed. New cross-section data are provided high neutron energies that go beyond limits...
Dipole-strength distributions in the nuclides $^{98}\mathrm{Mo}$ and $^{100}\mathrm{Mo}$ up to neutron-separation energies have been studied photon-scattering experiments at bremsstrahlung facility of Forschungszentrum Dresden-Rossendorf. To determine dipole-strength neutron-emission thresholds, statistical methods were developed for analysis measured spectra. The spectra scattered photons corrected detector response atomic background by simulations using code GEANT3. Simulations...
The cross section of the reaction $^{197}\mathrm{Au}$($n,\ensuremath{\gamma}$) was measured with time-of-flight technique at n_TOF (neutron time-of-flight) facility in unresolved resonance region between 5 and 400 keV using a pair ${\mathrm{C}}_{6}$D${}_{6}$ (where D denotes $^{2}\mathrm{H}$) liquid scintillators for detection prompt capture $\ensuremath{\gamma}$ rays. results total uncertainty $3.9%--6.7$$%$ resolution 20 bins per energy decade show fair agreement Evaluated Nuclear Data...
We have measured the neutron capture cross sections of stable magnesium isotopes ${}^{24,25,26}$Mg in energy range interest to $s$ process using time-of-flight facility n_TOF at CERN. Capture events from a natural metal sample and samples enriched ${}^{25}$Mg ${}^{26}$Mg were recorded total method based on C${}_{6}$${}^{2}$H${}_{6}$ detectors. Neutron resonance parameters extracted by simultaneous shape analysis present data existing transmission isotopic sample. Maxwellian-averaged for...
Our aim in the present work was to investigate changes of defect structure bulk niobium induced by hydrogen loading. The evolution microstructure with increasing concentration studied x-ray diffraction and two complementary techniques positron annihilation spectroscopy (PAS), namely lifetime slow implantation measurement Doppler broadening, defect-free Nb $(99.9%)$ containing a remarkable number dislocations. These samples were electrochemically loaded up...
The ($n,\ensuremath{\gamma}$) cross section of $^{197}\mathrm{Au}$ has been measured at n_TOF in the resolved resonance region, up to 5 keV, with aim improving accuracy an energy range where it is not yet considered standard. measurements were performed two different experimental setup and detection techniques, total method based on ${\mathrm{C}}_{6}$${\mathrm{D}}_{6}$ detectors, absorption calorimetry a 4$\ensuremath{\pi}$ BaF${}_{2}$ array. By comparing data collected accurate sets...
The $^{63}$Ni($n, \gamma$) cross section has been measured for the first time at neutron time-of-flight facility n\_TOF CERN from thermal energies up to 200 keV. In total, capture kernels of 12 (new) resonances were determined. Maxwellian Averaged Cross Sections calculated kT = 5 keV 100 with uncertainties around 20%. Stellar model calculations a 25 M$_\odot$ star show that new data have significant effect on $s$-process production $^{63}$Cu, $^{64}$Ni, and $^{64}$Zn in massive stars,...
The151Sm(n,gamma)152Sm cross section has been measured at the spallation neutron facility n_TOF CERN in energy range from 1 eV to MeV. The new combines excellent resolution time-of-flight, low repetition rates, and an unsurpassed instantaneous luminosity, resulting rather favorable signal/background ratios. 151Sm is of importance for characterizing capture nucleosynthesis asymptotic giant branch stars. At a thermal kT=30 keV Maxwellian averaged this unstable isotope (t(1/2)=93 yr) was...
Spectra of two-step gamma cascades following the thermal 162Dy(n,gamma)163Dy reaction have been measured. Distinct peaklike structures observed at midpoints these spectra are interpreted as a manifestation low-energy isovector M1 vibrational mode excited 163Dy nuclei.
We obtained an unprecedentedly large number of $s$-wave neutron widths through $\mathcal{R}$-matrix analysis cross-section measurements on enriched Pt samples. Careful these data rejects the validity Porter-Thomas distribution with a statistical significance at least 99.997%.
The neutron capture cross sections of the Zr isotopes have important implications in nuclear astrophysics and for reactor design. small section magic nucleus $^{90}\mathrm{Zr}$, which accounts more than 50% natural zirconium represents one key stellar $s$-process, because it acts as a bottleneck chain between Fe seed heavier isotopes. same element, Zr, also is an component structural materials used traditional advanced reactors. ($n,\ensuremath{\gamma}$) has been measured at CERN, using...