A5084004379- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Nuclear physics research studies
- Radiation Detection and Scintillator Technologies
- Nuclear Materials and Properties
- Atomic and Subatomic Physics Research
- Particle Detector Development and Performance
- Astro and Planetary Science
- Radiation Therapy and Dosimetry
- Particle physics theoretical and experimental studies
- X-ray Spectroscopy and Fluorescence Analysis
- Superconducting Materials and Applications
- Astronomical and nuclear sciences
- Particle Accelerators and Free-Electron Lasers
- High-Energy Particle Collisions Research
- Graphite, nuclear technology, radiation studies
- Gamma-ray bursts and supernovae
- Particle accelerators and beam dynamics
- Radioactive Decay and Measurement Techniques
- Advanced NMR Techniques and Applications
- Dark Matter and Cosmic Phenomena
- Quantum Chromodynamics and Particle Interactions
- Advanced Frequency and Time Standards
- Boron Compounds in Chemistry
- Fusion materials and technologies
University of Vienna
2015-2024
University of Basel
2011-2023
University of Edinburgh
2019-2023
European Organization for Nuclear Research
2021
Australian National University
2020
Istituto Nazionale di Fisica Nucleare, Sezione di Bari
2010-2019
Istituto Nazionale di Fisica Nucleare, Sezione di Bologna
2011-2017
Istituto Nazionale di Fisica Nucleare
2011-2017
University of Hull
2017
Universidade de Santiago de Compostela
2016
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...
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...
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$$%$ resolution 20 bins per energy decade show fair agreement Evaluated Nuclear Data...
The excitation function for the reaction 90Zr(n,2n)89Zr was measured from 12.3 to 19.5 MeV in steps of 0.2-0.8 using activation techniques. T(d,n)4He used produce neutrons. Neutron fluences were determined by means a proton-recoil telescope at 0 degrees and differential neutron production cross sections. Additionally, energy range 13.4-14.8 MeV, measurements performed smaller (0.04-0.15 MeV) relative well known sections reference 27Al(n, alpha )24Na. Activity 12.7 cm*12.7 cm Nai(Tl)...
The ($n,\ensuremath{\gamma}$) cross section of $^{197}\mathrm{Au}$ has been measured at n_TOF in the resolved resonance region, up to 5 keV, with aim improving accuracy an energy range where it is not yet considered standard. measurements were performed two different experimental setup and detection techniques, total method based on ${\mathrm{C}}_{6}$${\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...
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...
The ($n,\ensuremath{\gamma}$) reaction of the radioactive isotope ${}^{93}$Zr has been measured at n_TOF high-resolution time-of-flight facility CERN. Resonance parameters have extracted in neutron energy range up to 8 keV, yielding capture widths smaller (14$%$) than reported an earlier experiment. These results are important for detailed nucleosynthesis calculations and refined studies waste transmutation concepts.
The neutron sensitivity of the C$_6$D$_6$ detector setup used at n_TOF for capture measurements has been studied by means detailed GEANT4 simulations. A realistic software replica entire experimental hall, including beam line, sample, supports and walls area implemented in simulations have analyzed same manner as data, particular applying Pulse Height Weighting Technique. validated against a measurement background performed with $^\mathrm{nat}$C showing an excellent agreement above 1 keV. At...
This work reports on accurate, high-resolution measurements of the $^{25}$Mg($n, \gamma$)$^{26}$Mg and tot$) cross sections in neutron energy range from thermal to about 300 keV, leading a significantly improved parametrization. The relevant resonances for $n+^{25}$Mg were characterized combined R-matrix analysis experimental data. resulted an unambiguous spin/parity assignment corresponding excited states $^{26}$Mg. With this information upper limits reaction rates $^{22}$Ne($\alpha,...
^{140}Ce(n,γ) is a key reaction for slow neutron-capture (s-process) nucleosynthesis due to being bottleneck in the flow. For this reason, it was measured with high accuracy (uncertainty ≈5%) at n_TOF facility, an unprecedented combination of purity sample and low neutron-sensitivity detectors. The Maxwellian averaged cross section up 40% higher than previously accepted values. Stellar model calculations indicate reduction around 20% s-process contribution Galactic cerium abundance smaller...
The neutron capture cross section of $^{209}\mathrm{Bi}$ has been measured at the CERN n_TOF facility by employing pulse-height-weighting technique. Improvements over previous measurements are mainly because an optimized detection system, which led to a practically negligible sensitivity. Additional experimental sources systematic error, such as electronic threshold in detectors, summing \ensuremath{\gamma}-rays, internal electron conversion, and isomeric state bismuth, have taken into...
Neutron resonance analyses have been performed for the capture cross sections of $^{186}\mathrm{Os}$, $^{187}\mathrm{Os}$, and $^{188}\mathrm{Os}$ measured at n_TOF facility cern. Resonance parameters extracted up to 5, 3, 8 keV, respectively, using sammy code a full $R$-matrix fit yields. From these results average were derived by statistical analysis provide comprehensive experimental basis modeling stellar neutron rates isotopes in terms Hauser-Feshbach model. Consistent calculations...
Because the relatively small neutron capture cross sections of zirconium isotopes are difficult to measure, results previous measurements often not adequate for a number problems in astrophysics and nuclear technology. Therefore, $^{92}\mathrm{Zr}$($n,\ensuremath{\gamma}$) section has been remeasured at CERN n_TOF facility, providing set improved parameters 44 resonances energy range up 40 keV. With this information cross-section uncertainties keV region could be reduced $5%$ as required...
Neutron-induced fission cross sections for ${}^{\text{nat}}$Pb and $^{209}\mathrm{Bi}$ were measured with a white-spectrum neutron source at the CERN Neutron Time-of-Flight (n_TOF) facility. The experiment, using neutrons from threshold up to 1 GeV, provides first results these nuclei above 200 MeV. relative $^{235}\mathrm{U}$ $^{238}\mathrm{U}$ in dedicated chamber parallel plate avalanche counter detectors. Results are compared previous experimental data. Upgraded parametrizations of...
The cross section of the $^{62}$Ni($n,\gamma$) reaction was measured with time-of-flight technique at neutron facility n_TOF CERN. Capture kernels 42 resonances were analyzed up to 200~keV energy and Maxwellian averaged sections (MACS) from $kT=5-100$ keV calculated. With a total uncertainty 4.5%, stellar is in excellent agreement KADoNiS compilation $kT=30$ keV, while being systematically lower factor 1.6 higher temperatures. $^{63}$Ni($n,\gamma$) for first time n_TOF. We determined...