N. Patronis
A5010663115- Nuclear Physics and Applications
- Nuclear physics research studies
- Nuclear reactor physics and engineering
- Radiation Detection and Scintillator Technologies
- Nuclear Materials and Properties
- X-ray Spectroscopy and Fluorescence Analysis
- Astronomical and nuclear sciences
- Atomic and Subatomic Physics Research
- Radiation Therapy and Dosimetry
- Astro and Planetary Science
- Atomic and Molecular Physics
- Particle physics theoretical and experimental studies
- Particle Detector Development and Performance
- Quantum Chromodynamics and Particle Interactions
- Superconducting Materials and Applications
- Electron and X-Ray Spectroscopy Techniques
- Radiopharmaceutical Chemistry and Applications
- Particle accelerators and beam dynamics
- High-Energy Particle Collisions Research
- Advanced Chemical Physics Studies
- Ion-surface interactions and analysis
- Quantum, superfluid, helium dynamics
- Particle Accelerators and Free-Electron Lasers
- Boron Compounds in Chemistry
- Medical Imaging Techniques and Applications
University of Ioannina
2015-2024
Instituto de Física Corpuscular
2024
European Organization for Nuclear Research
2010-2024
Universitat de València
2024
Charles University
2009-2024
Institut National de Physique Nucléaire et de Physique des Particules
2007-2023
Université Paris-Saclay
2017-2023
Université Paris-Sud
2017-2023
Centre National de la Recherche Scientifique
2007-2023
Institut de Physique
2017-2023
A very exotic process of $\ensuremath{\beta}$-delayed fission $^{180}\mathrm{Tl}$ is studied in detail by using resonant laser ionization with subsequent mass separation at ISOLDE (CERN). In contrast to common expectations, the fission-fragment distribution post-$\ensuremath{\beta}$-decay daughter nucleus $^{180}\mathrm{Hg}$ ($N/Z=1.25$) asymmetric. This asymmetry more surprising since a mass-symmetric split this extremely neutron-deficient would lead two $^{90}\mathrm{Zr}$ fragments, magic...
The Miniball germanium detector array has been operational at the REX (Radioactive ion beam EXperiment) post accelerator Isotope Separator On-Line facility ISOLDE CERN since 2001. During last decade, a series of successful Coulomb excitation and transfer reaction studies have performed with this array, utilizing unique high-quality radioactive beams which are available ISOLDE. In article, an overview is given technical details full setup, including description $\gamma$ -ray particle...
The "island of inversion" nucleus 32 Mg has been studied by a (t, p) two neutron transfer reaction in inverse kinematics at REX-ISOLDE. shape coexistent excited 0+ state identified the characteristic angular distribution protons Δ L=0 transfer. excitation energy 1058 keV is much lower than predicted any theoretical model. low γ-ray intensity observed for decay this indicates lifetime more 10 ns. Deduced spectroscopic amplitudes are compared with occupation numbers from shell-model calculations.
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...
Coulomb-excitation experiments to study electromagnetic properties of radioactive even-even Hg isotopes were performed with $2.85\text{ }\mathrm{MeV}/\mathrm{nucleon}\text{ }\mathrm{mercury}$ beams from REX-ISOLDE. Magnitudes and relative signs the reduced $E2$ matrix elements that couple ground state low-lying excited states in $^{182\ensuremath{-}188}\mathrm{Hg}$ extracted. Information on deformation first ${0}^{+}$ was deduced using quadrupole sum rules approach. Results show is slightly...
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...
The $^{7}\mathrm{Li}+^{28}\mathrm{Si}$ elastic scattering was studied at near-barrier energies, namely, 8, 8.5, 9, 10, 11, 13, 15, and $16\phantom{\rule{0.3em}{0ex}}\text{MeV}$, with the aim to map real imaginary part of optical potential therefore probe threshold anomaly. Angular distributions were measured over a wide angular range (${\ensuremath{\theta}}_{\mathrm{lab}}=25\ifmmode^\circ\else\textdegree\fi{}$ $150\ifmmode^\circ\else\textdegree\fi{}$) for lower energies...
Collective properties of the low-lying levels in odd-A Cu67–73 were investigated by Coulomb excitation with radioactive beams. The beams produced at ISOLDE and postaccelerated REX-ISOLDE up to 2.99 MeV/u. In Cu67,69, 1/2−, 5/2−, 7/2− states populated. Cu71,73, besides known transitions deexciting single-particle-like 5/2− core-coupled levels, γ rays 454 135 keV, respectively, observed for first time. Based on a reanalysis β-decay work comparison systematics, spin 1/2− is suggested these...
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...
One of the challenges nuclear astrophysics is understanding observed abundances p-process nuclei. Nucleosynthesis calculations typically employ an extended reaction network involving tens thousands reactions and isotopes. As it impossible to experimentally investigate such a vast number reactions, these rely heavily on cross sections derived from Hauser-Feshbach (HF) theory. To improve predictive power HF theory, important provide updated parameterization incorporated models, validated...
The 6Li+28Si elastic scattering was studied at near-barrier energies with the aim to probe threshold anomaly. Angular distributions were measured over a wide angular range (θlab=25° 150°) 4 energies, namely, 7.5, 9, 11 and 13 MeV. present data together previous ones higher as well of 6Li on various targets near barrier analyzed by using optical potentials obtained in double-folding framework. It found that strength real part potential remains almost independent energy down to, possible even...
The 62Ni(n,gamma)63Ni(t_1/2=100+-2 yrs) reaction plays an important role in the control of flow path slow neutron-capture (s-) nucleosynthesis process. We have measured for first time total cross section this a quasi-Maxwellian (kT = 25 keV) neutron flux. measurement was performed by fast-neutron activation, combined with accelerator mass spectrometry to detect directly 63Ni product nuclei. experimental value 28.4+-2.8 mb, fairly consistent recent theoretical estimate, affects calculated net...
The neutron capture cross section of $^{14}\mathrm{C}$ is relevance for several nucleosynthesis scenarios such as inhomogeneous Big Bang models, induced CNO cycles, and neutrino driven wind models the $r$ process. $^{14}\mathrm{C}$($n,\ensuremath{\gamma}$) reaction also important validation Coulomb dissociation method, where ($n,\ensuremath{\gamma}$) can be indirectly obtained via time-reversed So far, example only case with neutrons both, direct measurement indirect dissociation, have been...
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 β+/EC decay of 180Tl and excited states in the daughter nucleus 180Hg have been investigated at CERN On-Line Isotope Mass Separator (ISOLDE) facility. Many new low-lying energy levels were observed 180Hg, which most significant are 0+2 419.6 keV 2+2 601.3 keV. former is bandhead an band assumed originally to be prolate nature. From β feeding different ground-state spin was deduced (4−,5−).3 MoreReceived 23 June 2011DOI:https://doi.org/10.1103/PhysRevC.84.034307©2011 American Physical Society
The detailed analysis of the β-delayed fission data 180Tl is presented. experiment was performed by producing a pure beam means highly selective resonance laser ionization followed mass separation with ISOLDE (CERN, Geneva) isotope separator. A surprising asymmetric distribution fragments from 180Hg, daughter β decays, observed. Here, energy calibration silicon detectors, which crucial for proper determination fragments' and split, presented total kinetic its dependence on split ratio...
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.
Abstract This article presents a few selected developments and future ideas related to the measurement of $$(n,\gamma )$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mo>(</mml:mo> <mml:mi>n</mml:mi> <mml:mo>,</mml:mo> <mml:mi>γ</mml:mi> <mml:mo>)</mml:mo> </mml:mrow> </mml:math> data astrophysical interest at CERN n_TOF. The MC-aided analysis methodology for use low-efficiency radiation detectors in time-of-flight neutron-capture measurements is discussed, with...
The neutron time-of-flight facility n_TOF at CERN is a spallation source dedicated to measurements of neutron-induced reaction cross-sections interest in nuclear technologies, astrophysics, and other applications. Since 2014, Experimental ARea 2 (EAR2) operational delivers fluence ∼4⋅107 neutrons per nominal proton pulse, which ∼50 times higher than the one 1 (EAR1) ∼8⋅105 pulse. high flux EAR2 results counting rates detectors that challenged previously existing capture detection systems....
^{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...