A5001957668- Nuclear physics research studies
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Quantum Chromodynamics and Particle Interactions
- Advanced Chemical Physics Studies
- Advanced NMR Techniques and Applications
- Quantum, superfluid, helium dynamics
- Astronomical and nuclear sciences
- Atomic and Subatomic Physics Research
- Nuclear reactor physics and engineering
- X-ray Spectroscopy and Fluorescence Analysis
- Particle accelerators and beam dynamics
- Inorganic Fluorides and Related Compounds
- Particle physics theoretical and experimental studies
- Astro and Planetary Science
- Radiation Therapy and Dosimetry
- Cold Atom Physics and Bose-Einstein Condensates
- Gamma-ray bursts and supernovae
- Fluorine in Organic Chemistry
- Dark Matter and Cosmic Phenomena
- Medical Imaging Techniques and Applications
- Atmospheric Ozone and Climate
- Electron and X-Ray Spectroscopy Techniques
- Radiation Detection and Scintillator Technologies
- Stellar, planetary, and galactic studies
Texas A&M University
2014-2024
Kurchatov Institute
1999-2011
Czech Academy of Sciences, Nuclear Physics Institute
2011
Ghulam Ishaq Khan Institute of Engineering Sciences and Technology
2010-2011
Université Paris-Sud
2011
Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali del Sud
2009-2011
University of Jyväskylä
2009-2011
Institut National de Physique Nucléaire et de Physique des Particules
2010-2011
Centre National de la Recherche Scientifique
2010-2011
Mitchell Institute
2005-2011
The three-body breakup ${}^{6}{\stackrel{\ensuremath{\rightarrow}}{\mathrm{He}}}^{4}\mathrm{He}+n+n$ is studied experimentally, using a secondary ${}^{6}\mathrm{He}$ ion beam of 240 MeV/nucleon incident on carbon and lead targets. Integrated cross sections for one- two-neutron knockout differential $d\ensuremath{\sigma}{/dE}^{*}$ $d\ensuremath{\sigma}/d\ensuremath{\vartheta}$ inelastic nuclear or electromagnetic excitations into the continuum are presented. $E$1-strength distribution deduced...
The 18O(p, α)15N reaction is of primary importance to pin down the uncertainties, due nuclear physics input, affecting present-day models asymptotic giant branch stars. Its rate can modify both fluorine nucleosynthesis inside such stars and oxygen nitrogen isotopic ratios, which allow one constrain proposed astrophysical scenarios. Thus, an indirect measurement low-energy region has been performed access, for first time, range relevance application. In particular, a full, high-accuracy...
The reaction ${}^{17}\mathrm{O}(n,\ensuremath{\alpha}){}^{14}\mathrm{C}$ was studied at energies from ${E}_{\mathrm{c}.\mathrm{m}.}=0$ to ${E}_{\mathrm{c}.\mathrm{m}.}=350\phantom{\rule{0.28em}{0ex}}\mathrm{keV}$ by using the quasifree deuteron breakup in three-body ${}^{17}\mathrm{O}+d\ensuremath{\rightarrow}\ensuremath{\alpha}+{}^{14}\mathrm{C}+p$, which extended Trojan Horse indirect method (THM) neutron-induced reactions. It is found that ${}^{18}\mathrm{O}$ excited state...
The $^{18}\mathrm{O}(p,\ensuremath{\alpha})^{15}\mathrm{N}$ reaction is of primary importance in several astrophysical scenarios, including fluorine nucleosynthesis inside asymptotic giant branch stars as well oxygen and nitrogen isotopic ratios meteorite grains. Thus the indirect measurement low energy region has been performed to reduce nuclear uncertainty on theoretical predictions. In particular strength 20 90 keV resonances deduced change rate evaluated.
Background: Clustering phenomena in $N\ensuremath{\ne}Z$ nuclei provide an opportunity to understand the interplay between cluster and nucleon degrees of freedom.Purpose: To study resonances ${}^{18}\mathrm{O}$ spectrum, populated ${}^{14}\mathrm{C}+\ensuremath{\alpha}$ elastic scattering.Method: The thick target inverse kinematics technique was used measure excitation function for scattering. A 42-MeV ${}^{14}\mathrm{C}$ beam populate states energy up 14.9 MeV ${}^{18}\mathrm{O}$. analysis...
The study of the $^{17}\mathrm{O}(n,\ensuremath{\alpha})^{14}\mathrm{C}$ reaction has been performed by means Trojan horse method (THM) applied to quasifree $^{2}\mathrm{H}(^{17}\mathrm{O},\ensuremath{\alpha}^{14}\mathrm{C})^{1}\mathrm{H}$ induced at a beam energy 43.5 MeV. THM allowed us 8121-keV $^{18}\mathrm{O}^{*}$ resonant level, for which previous investigation pointed out ability overcome centrifugal barrier suppression effects in entrance channel. Here, view developments reactions,...
Resonances in the unbound nucleus N11 have been studied, using resonance scattering reaction C10+p. The data give evidence for three states above C10+p threshold with energies 1.30, 2.04, and 3.72 MeV. These can be interpreted, a potential-model analysis, as ground state first two excited spin-parity 12+, 12−, 52+ arising from shell-model orbitals 1s12, 0p12, 0d52. A narrow superposed on broad structure found at higher energy could interpreted mirror of 32− Be11 shifted down energy. This...
The low-energy bare-nucleus cross section for $^{15}\mathrm{N}$$(p,\ensuremath{\alpha})$$^{12}\mathrm{C}$ is extracted by means of the Trojan horse method applied to $^{2}\mathrm{H}$($^{15}\mathrm{N}$,$\ensuremath{\alpha}$$^{12}\mathrm{C}$)$n$ reaction at ${E}_{\mathrm{beam}}=60$ MeV. For first time we modified half-off-energy-shell resonant $R$-matrix that takes into account off-energy-shell effects and initial- final-state interactions. In particular it has been shown inclusion Coulomb...
The ${}^{15}\mathrm{N}(p,\ensuremath{\gamma}){}^{16}\mathrm{O}$ reaction provides a path from the CN cycle to CNO bi-cycle and tri-cycle. measured astrophysical factor for this is dominated by resonant capture through two strong ${J}^{\ensuremath{\pi}}={1}^{\ensuremath{-}}$ resonances at ${E}_{R}=312$ 962 keV direct ground state. Asymptotic normalization coefficients (ANCs) seven excited states in $^{16}\mathrm{O}$ were extracted comparison of experimental differential cross sections...
In 1954 Fred Hoyle postulated that a 7.65 MeV excited state in ${}^{12}$C had to exist for carbon-based life develop on Earth. During stellar helium burning, such allows short-lived ${}^{8}$Be, formed from two $\ensuremath{\alpha}$ particles, resonantly react with third particle form this which can decay the ground via $\ensuremath{\gamma}$ or electron-positron pair emission. The branching fraction radiative determines amount of produced stars. A recent experiment suggested was significantly...
Peripheral fragmentation of a 240 MeV͞nucleon beam the halo nucleus 6 He incident on carbon target has been studied in kinematically complete experiment.It is found that one-neutron stripping to unbound 5 dominant mechanism and it leads spin alignment plane perpendicular momentum vector.This expected be common feature for all neutron nuclei.
The ground and first excited states in $^{15}\mathrm{F}$ were studied resonant elastic scattering using the thick $({\text{CH}}_{4})$ gas target method inverse kinematics with a separated $^{14}\mathrm{O}$ beam. An analysis of excitation functions was carried out potential model. quantum numbers $1∕{2}^{+}$ (ground state) $5∕{2}^{+}$ (first assigned to lowest two $^{15}\mathrm{F}$. Also, widths proton decay energies unbound levels obtained. data indicates that large diffuseness is needed...
We present new improved $R$ matrix fits of direct data and indirect Trojan Horse for the $^{15}\mathrm{N}(p,\ensuremath{\alpha})^{12}\mathrm{C}$ reaction provide a more accurate recommended value $S(0)=73.0\ifmmode\pm\else\textpm\fi{}5.0$ MeV b from Redder [A. et al., Z. Phys. A 305, 325 (1982)] $S(0)=70.0\ifmmode\pm\else\textpm\fi{}13.5$ [M. La Cognata Rev. C 76, 065804 (2007)]. also analyze recent fit by Barker [F. C. Barker, 78, 044611 (2008)] demonstrate that when all uncertainties are...
We measured the excitation function for 13O + p elastic scattering to obtain data on unknown 14F nucleus. The ground state and several low-lying excited states in were observed spin/parity assignments made. appears be much less unstable than was predicted. compare theoretical predictions level scheme with experimental results.
The structure of the 18O nucleus at excitation energies above alpha decay threshold was studied using 14C+alpha resonance elastic scattering. A number states with large reduced widths have been observed, indicating that alpha-cluster degree freedom plays an important role in this N not equal Z nucleus. However, is very different from relatively simple pattern strong quasi-rotational bands neighboring 16O and 20Ne nuclei. 0+ state width exceeding single particle limit identified energy...
Background: Multicenter (molecular) structures can play an important role in light nuclei. The highly deformed rotational band ${}^{10}$Be with a bandhead at 6.179 MeV has been observed recently and suggested to have exotic $\ensuremath{\alpha}$:$2n$:$\ensuremath{\alpha}$ configuration.Purpose: Search for states $\ensuremath{\alpha}$:$pn$:$\ensuremath{\alpha}$ two-center molecular configurations ${}^{10}$B that are analogous the structure ${}^{10}$Be.Methods: $T=1$ isobaric analog were...
Identification of alpha cluster states analogous to the 12C Hoyle state in heavier alpha- conjugate nuclei can provide tests existence condensates nuclei. Such are predicted for 16O, 20Ne, 24Mg, 28Si etc. at excitation energies slightly above multi-alpha particle decay threshold, but have not yet been experimentally identified. The Thick Target Inverse Kinematics (TTIK) technique be used study breakup excited self-conjugate into many particles. reaction 20Ne+{\alpha} was studied using a 20Ne...
The 22Ne(α,γ)26Mg and 22Ne(α,n)25Mg reactions play an important role in astrophysics because they have significant influence on the neutron flux during weak branch of s-process. We constrain astrophysical rates for these by measuring partial α-widths resonances 26Mg located Gamow window Ne22+α capture. These were populated using 22Ne(6Li,d)26Mg 22Ne(7Li,t)26Mg at energies near Coulomb barrier. At low α-transfer favor population spin states extracted observed exhibit only minor dependence...
The level structure of the unbound nucleus 11N has been studied by 10C+p elastic resonance scattering in inverse geometry with LISE3 spectrometer at GANIL, using a 10C beam an energy 9.0 MeV/nucleon. An additional measurement was done A1200 MSU. excitation function above threshold determined up to 5 MeV. A potential-model analysis revealed three states energies 1.27−0.05+0.18 MeV (Γ=1.44±0.2 MeV), 2.01−0.05+0.15 (Γ=0.84±0.2 and 3.75±0.05 (Γ=0.60±0.05 MeV) spin-parity assignments...
An excitation function for resonance elastic scattering of $\ensuremath{\alpha}$ particles on $^{18}\mathrm{O}$ and $^{18}\mathrm{Ne}$ was measured using the method inverse geometry with a very thick target. Spectroscopic information obtained 23 levels in energy region from 11.9 to $13.7\phantom{\rule{0.3em}{0ex}}\text{MeV}$ $^{22}\mathrm{Ne}$. Twelve them are new. General features $\ensuremath{\alpha}$-cluster bands $^{22}\mathrm{Ne}$ analyzed framework potential model deep well....
The interaction of ${}^{8}\mathrm{Li}$ with ${}^{208}\mathrm{Pb}$ has been studied over a range energies near the nominal Coulomb barrier. An excitation function for total reaction cross section is obtained from elastic-scattering angular distributions and compared existing data ${}^{6,7}\mathrm{Li}$ scattering. result this comparison indicates that barrier ${}^{8}\mathrm{Li}{+}^{208}\mathrm{Pb}$ reduced by approximately 4 MeV relative to ${}^{7}\mathrm{Li}.$ yields ${}^{7}\mathrm{Li}$...
The reaction $^{13}\mathrm{C}(\ensuremath{\alpha},n)$ is considered to be the main source of neutrons for $s$ process in asymptotic giant branch stars. At low energies, cross section dominated by $1/{2}^{+}$ 6.356 MeV subthreshold resonance $^{17}\mathrm{O}$ whose contribution at stellar temperatures uncertain a factor 10. In this work, we performed most precise determination low-energy astrophysical $S$ using indirect normalization (ANC) technique. $\ensuremath{\alpha}$-particle ANC state...