F. L. Bello Garrote
A5025475943- Nuclear physics research studies
- Astronomical and nuclear sciences
- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Atomic and Molecular Physics
- Quantum Chromodynamics and Particle Interactions
- Advanced Chemical Physics Studies
- Particle physics theoretical and experimental studies
- Rare-earth and actinide compounds
- High-pressure geophysics and materials
- Particle accelerators and beam dynamics
- X-ray Spectroscopy and Fluorescence Analysis
- Radiation Detection and Scintillator Technologies
- Particle Accelerators and Free-Electron Lasers
- Astro and Planetary Science
- Gamma-ray bursts and supernovae
- Neutrino Physics Research
- Superconducting Materials and Applications
- Advanced NMR Techniques and Applications
- Radioactive Decay and Measurement Techniques
- Radiopharmaceutical Chemistry and Applications
- Radiation Therapy and Dosimetry
- Fractal and DNA sequence analysis
- Inorganic Fluorides and Related Compounds
- advanced mathematical theories
University of Oslo
2016-2025
GSI Helmholtz Centre for Heavy Ion Research
2017
Proton-<a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mi>γ</a:mi></a:math> coincidences from <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mrow><b:mo>(</b:mo><b:mi>d</b:mi><b:mo>,</b:mo><b:mi>p</b:mi><b:mo>)</b:mo></b:mrow></b:math> reactions between a <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"><c:mmultiscripts><c:mi>Ni</c:mi><c:mprescripts/><c:none/><c:mn>66</c:mn></c:mmultiscripts></c:math> beam and deuterated polyethylene target have been analyzed with the...
The β-decay half-lives of 94 neutron-rich nuclei ^{144-151}Cs, ^{146-154}Ba, ^{148-156}La, ^{150-158}Ce, ^{153-160}Pr, ^{156-162}Nd, ^{159-163}Pm, ^{160-166}Sm, ^{161-168}Eu, ^{165-170}Gd, ^{166-172}Tb, ^{169-173}Dy, ^{172-175}Ho, and two isomeric states ^{174m}Er, ^{172m}Dy were measured at the Radioactive Isotope Beam Factory, providing a new experimental basis to test theoretical models. Strikingly large drops are observed neutron-number N=97 for _{58}Ce, _{59}Pr, _{60}Nd, _{62}Sm, N=105...
Excited states in the $N=102$ isotones $^{166}\mathrm{Gd}$ and $^{164}\mathrm{Sm}$ have been observed following isomeric decay for first time at RIBF, RIKEN. The half-lives of measured to be 950(60) 600(140) ns $^{164}\mathrm{Sm}$, respectively. Based on patterns potential energy surface calculations, including ${\ensuremath{\beta}}_{6}$ deformation, a spin parity ${6}^{\ensuremath{-}}$ has assigned both nuclei. Collective observables are discussed light systematics region, giving insight...
The γ-ray strength functions and nuclear level densities of 138La 139La have been measured below the neutron separation energies. These new data were used to calculate astrophysical Maxwellian-averaged (n,γ) cross-sections investigate production destruction p-nucleus in photodisintegration process. results confirm underproduction p-process with respect observed abundances strongly support ν-process through νe capture on 138Ba as main contributor synthesis Type II supernovae.
The level structures of 70Co and 70Ni, populated from the β decay 70Fe, have been investigated using β-delayed γ-ray spectroscopy following in-flight fission a 238U beam. experimental results are compared to Monte-Carlo Shell-Model calculations including pf+g9/2+d5/2 orbitals. strong population (1+) state at 274 keV in is variance with expected excitation energy ∼1 MeV near spherical single-particle estimates. This observation indicates dominance prolate-deformed intruder configurations...
The cascading 3.21 and 4.44 MeV electric quadrupole transitions have been observed from the Hoyle state at 7.65 excitation energy in ^{12}C, excited by ^{12}C(p,p^{'}) reaction 10.7 proton energy. From proton-γ-γ triple coincidence data, a value of Γ_{rad}/Γ=6.2(6)×10^{-4} was obtained for radiative branching ratio. Using our results, together with Γ_{π}^{E0}/Γ Eriksen et al. [Phys. Rev. C 102, 024320 (2020)PRVCAN2469-998510.1103/PhysRevC.102.024320] currently adopted Γ_{π}(E0) values, width...
The experimental gamma-ray strength functions (gamma-SFs) of 142,144-151Nd have been studied for energies up to the neutron separation energy. results represent a unique set gamma-SFs an isotopic chain with increasing nuclear deformation. data reveal how low-energy enhancement, scissors mode and pygmy dipole resonance evolve deformation mass number. indicate that mechanisms behind enhancement are decoupled from each other.
The nuclear level density and the $\ensuremath{\gamma}$-ray strength function have been extracted for $^{89}\mathrm{Y}$ by using Oslo method on $^{89}\mathrm{Y}(p,{p}^{\ensuremath{'}}\ensuremath{\gamma})^{89}\mathrm{Y}$ coincidence data. displays a low-energy enhancement consistent with previous observations in this mass region $(^{93\text{--}98}\mathrm{Mo})$. Shell-model calculations support conclusion that observed is due to strong, $M1$ transitions at high excitation energies. data were...
The $\beta$-decay half-lives of 55 neutron-rich nuclei $^{134-139}$Sn, $^{134-142}$Sb, $^{137-144}$Te, $^{140-146}$I, $^{142-148}$Xe, $^{145-151}$Cs, $^{148-153}$Ba, $^{151-155}$La were measured at the Radioactive Isotope Beam Factory (RIBF) employing projectile fission fragments $^{238}$U. nuclear level structure, which relates to deformation, has a large effect on half-lives. impact newly-measured modeling astrophysical origin heavy elements is studied in context $r$ process...
The validity of the Brink-Axel hypothesis, which is especially important for numerous astrophysical calculations, addressed ^{116,120,124}Sn below neutron separation energy by means three independent experimental methods. γ-ray strength functions (GSFs) extracted from primary γ-decay spectra following charged-particle reactions with Oslo method and shape demonstrate excellent agreement those deduced forward-angle inelastic proton scattering at relativistic beam energies. In addition, GSFs...
The γ-ray strength functions (GSF) and nuclear level densities (NLD) below the neutron separation energy were extracted for 111−113,116−122,124 Sn from particle-γ coincidence data with Oslo method in a model consistent way. Combined results of recent systematic Coulomb excitation study, GSFs used to extract bulk characteristics low-lying electric dipole response, commonly associated pygmy resonance (PDR). A resonance-like peak on top tail isovector giant was observed all isotopes. It is...
A campaign of Coulomb-excitation experiments to study the electromagnetic structure \(^{110}\)Cd was performed using beams \(^{14}\)N, \(^{32}\)S, and \(^{60}\)Ni. The use various reaction partners enables disentangling contributions individual matrix elements involved in excitation process, yielding, among others, a precise determination lifetime 2\(^+_2\) state \(^{110}\)Cd. Abstract Published by Jagiellonian University 2025 authors
The low-lying electric dipole strength in \(^{111-113,116-122,124}\)Sn was extracted with the Oslo method to systematically investigate pygmy resonance (PDR) and its evolution Sn isotopes. nuclear level densities (NLD) \(\gamma \)-ray functions (GSF) obtained from data were used as inputs <span class="sf">TALYS</span> reaction code produce radiative neutron-capture cross sections, Maxwellian-averaged rates relevant for heavy-element nucleosynthesis. Despite a relatively small...
We study for the first time internal structure of 140Te through β-delayed γ-ray spectroscopy 140Sb. The very neutron-rich 140Sb nuclei with Z=51 and N=89 were produced by in-flight fission 238U beams at Radioactive Isotope Beam Factory, RIKEN. half-life spin-parity are reported as 173±12 ms 3−, respectively. In addition to excited states β-decay branch, one-neutron two-neutron emission branches also established. By identifying 2+ 4+ 140Te, we found that Te isotopes persist in their vibrator...
We have made a thorough study of the low-energy behavior $\ensuremath{\gamma}$-ray strength function within framework shell model. performed large-scale calculations spanning isotopic and isotonic chains over several mass regions, considering 283 nuclei in total, with purpose studying systematic enhancement (LEE) for $M1$ transitions. There are clear trends calculations: From being nearly absent lowest region, LEE becomes steeper more pronounced as number increases, given region it further...
The decay of a new four-quasiparticle isomeric state in 160Sm has been observed using γ-ray spectroscopy at the RIBF, RIKEN. is assigned 2π⊗2ν π52−[532], π52+[413], ν52−[523], ν72+[633] configuration. half-life this (11+) measured to be 1.8(4) μs. isomer decays into rotational band structure, based on (6−) ν52−[523]⊗ν72+[633] bandhead, consistent with gK−gR values. This (5−) two-proton quasiparticle state, which turn ground band. Potential energy surface and blocked-BCS calculations were...
We report on the first β-decay data of Sb138 to Te138 isotopes beyond doubly magic Sn132. The parent nucleus was produced by in-flight fission a U238 beam Be9 target at 345 MeV per nucleon and measured BigRIPS separator Radioactive Isotope Beam Factory RIKEN. By using advanced β−γ spectroscopy techniques, half-life tentative spin-parity were be 346(19) ms (3−), respectively. In addition, we observed several low-lying non-yrast states in for time. Our allowed us rearrange positions 2+ 4+ this...
Low-lying excited states in $^{72}\mathrm{Ni}$ have been investigated an in-flight fission experiment at the RIBF facility of RIKEN Nishina Center. The combination state-of-the-art BigRIPS and EURICA setups has allowed for a very accurate study $\ensuremath{\beta}$ decay from $^{72}\mathrm{Co}$ to $^{72}\mathrm{Ni}$, provided first experimental information on sequence $^{72}\mathrm{Fe}\ensuremath{\rightarrow}^{72}\mathrm{Co}\ensuremath{\rightarrow}^{72}\mathrm{Ni}$ delayed neutron-emission...
Excited states in the nucleus $^{133}\mathrm{Sn}$, with one neutron outside double magic $^{132}\mathrm{Sn}$ core, were populated following one-neutron knockout from a $^{134}\mathrm{Sn}$ beam on carbon target at relativistic energies Radioactive Isotope Beam Factory RIKEN. Besides $\ensuremath{\gamma}$ rays emitted decay of known single-particle $^{133}\mathrm{Sn}$ additional strength energy range 3.5--5.5 MeV was observed for first time. Since neutron-separation is low,...
In this article we report on the first spectroscopic information Sb8951140 and observation of an isomer in nucleus with T1/2=41(8) μs. It is located close proximity to Sn140 for N=90, where νf7/2 orbit completely filled. The possible origin isomeric state a πg7/21×νf7/2−1 coupling configuration, resulting (6−) or (7−) spin-parity. This likely caused by inversion πg7/2 πd5/2 orbitals at N=89. existence such far from stability discussed extensively context shell-model calculations compared...
The new Oslo Scintillator Array (OSCAR) has been commissioned at the Cyclotron Laboratory (OCL). It consists of 30 large volume (diameter 3.5 x 8 inches) LaBr$_3$(Ce) detectors that are used for $\gamma$-ray spectroscopy. response functions incident $\gamma$-rays up to 20 MeV simulated with $\texttt{Geant4}$. In addition, resolution, and total full-energy peak efficiencies extracted. results in very good agreement measurements from calibration sources experimentally obtained mono-energetic...
The nuclear level densities and $\gamma$-ray strength functions of $^{138,139,140}$La were measured using the $^{139}$La($^{3}$He, $\alpha$), $^{3}$He$^\prime$) $^{139}$La(d, p) reactions. particle-$\gamma$ coincidences recorded with silicon particle telescope (SiRi) NaI(Tl) (CACTUS) arrays. In context these experimental results, low-energy enhancement in A$\sim$140 region is discussed. $^{137,138,139}$La($n, \gamma)$ cross sections calculated at $s$- $p$-process temperatures experimentally...
The low-lying structures of the midshell $\nu g_{9/2}$ Ni isotopes $^{72}$Ni and $^{74}$Ni have been investigated at RIBF facility in RIKEN within EURICA collaboration. Previously unobserved states were accessed for first time following $\beta$ decay mother nuclei $^{72}$Co $^{74}$Co. As a result, we provide complete picture terms seniority scheme up to $(8^+)$ levels both nuclei. experimental results are compared shell-model calculations order define what extent quantum number is preserved...
Particle-$\ensuremath{\gamma}$ coincidence data have been analyzed to obtain the nuclear level density and $\ensuremath{\gamma}$-strength function of $^{64}\mathrm{Ni}$ by means Oslo method. The found in this work is very good agreement with known energy levels at low excitation energies as well deduced from particle-evaporation measurements above ${E}_{x}\ensuremath{\approx}5.5$ MeV. experimental presents an enhancement $\ensuremath{\gamma}$ below...