B. Pietras
A5066084947- Nuclear physics research studies
- Nuclear Physics and Applications
- Nuclear reactor physics and engineering
- Radiation Detection and Scintillator Technologies
- Astronomical and nuclear sciences
- Particle Detector Development and Performance
- Atomic and Molecular Physics
- Quantum, superfluid, helium dynamics
- Gamma-ray bursts and supernovae
- Atomic and Subatomic Physics Research
- High-Energy Particle Collisions Research
- Medical Imaging Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Advanced Chemical Physics Studies
- Advanced NMR Techniques and Applications
- Laser-Plasma Interactions and Diagnostics
- Astro and Planetary Science
- High-pressure geophysics and materials
- Statistical and numerical algorithms
- Radioactivity and Radon Measurements
- Medical Imaging and Pathology Studies
- Mass Spectrometry Techniques and Applications
- Fusion materials and technologies
- Scientific Research and Discoveries
- Pulsars and Gravitational Waves Research
Universidade de Santiago de Compostela
2013-2022
Canadian Nuclear Laboratories
2020
University of Liverpool
2009-2018
We report on direct time-of-flight based mass measurements of 16 light neutron-rich nuclei. These include the first determination masses Borromean drip-line nuclei $^{19}\mathrm{B}$, $^{22}\mathrm{C}$, and $^{29}\mathrm{F}$ as well that $^{34}\mathrm{Na}$. In addition, most precise determinations to date for $^{23}\mathrm{N}$ $^{31}\mathrm{Ne}$ are reported. Coupled with recent interaction cross-section measurements, present results support occurrence a two-neutron halo in dominant...
The s-wave neutron fraction of the 0+ levels in 12Be has been investigated for first time through 11Be(d,p) transfer reaction using a 5A MeV 11Be beam at TRIUMF, Canada. populated all known bound states 12Be. ground state spectroscopic factor was determined to be 0.28−0.07+0.03 while that long-lived 02+ excited 0.73−0.40+0.27. This observation, together with smaller effective separation energy indicates enhanced probability an extended density tail beyond 10Be core compared state.
The quenching of the $N=20$ shell gap in neutron-rich nuclei is investigated by studying single-particle structure ${}^{27}$Ne via neutron transfer using a ${}^{26}$Ne beam. Two low-lying negative-parity intruder states have been observed, lowest which identified as ${J}^{\ensuremath{\pi}}=3/{2}^{\ensuremath{-}}$, confirming earlier speculations. A level 7/2${}^{\ensuremath{-}}$ observed higher energy than 3/2${}^{\ensuremath{-}}$, contrary to ordering at $\ensuremath{\beta}$-stability and...
The two fragments produced in fission reactions induced by $^{208}\mathrm{Pb}$ projectiles impinging on a liquid hydrogen target at $500A\phantom{\rule{0.28em}{0ex}}\mathrm{MeV}$ have been fully identified coincidence. experiment was performed GSI Darmstadt, where the combined use of inverse kinematics technique with an efficient detection setup permitted one to detect and identify range from $Z=27$ $Z=52$. corresponding isotopic cross sections velocities were measured high accuracy. results...
The spectroscopy of O21 has been investigated using a radioactive O20 beam and the (d,p) reaction in inverse kinematics. ground first excited states have determined to be Jπ=5/2+ 1/2+, respectively. Two neutron unbound were observed at excitation energies 4.77(10) 6.17(11) MeV. spectroscopic factor deduced for lower these, interpreted as 3/2+ level, reveals relatively pure (60%) 0d3/2 single-particle configuration, good agreement with shell-model calculations that predict O26 unbound. large...
The ground state of the proton-rich nucleus 23Al has been studied by one-proton removal on a carbon target at about 50 MeV/nucleon using EXOGAM + SPEG experimental setup GANIL. Longitudinal momentum distributions 22Mg breakup fragments, inclusive and in coincidence with γ rays de-exciting residues, were measured. ground-state structure is found to be configuration mixing d-orbital valence proton coupled four core states—0+gs, 2+1, 4+1, 4+2. We confirm spin parity as Jπ=5/2+. measured...
Total fission cross sections of $^{208}\mathrm{Pb}$ induced by protons have been determined at $370A,500A$, and $650A$ MeV. The experiment was performed GSI Darmstadt where the combined use inverse kinematics technique with an efficient detection setup allowed us to determine these uncertainty below $6%$. This result achieved accurate beam selection registration both fragments in coincidence which were also clearly distinguished from other reaction channels. These data solve existing...
A complete kinematics measurement of the two fission fragments was used for first time to investigate dynamics at small and large deformations. Fissioning systems with high excitation energies, compact shapes, low angular momenta were produced in inverse by using spallation reactions lead projectiles. new generation experimental setup allowed full unambiguous identification mass atomic number both fragments. This permitted us accurately determine cross sections, charge distribution, neutron...
The nuclear level density is one of the main ingredients for statistical description fission process. In this work, we propose to constrain parameter by using reactions induced protons and light ions on $^{208}\text{Pb}$ at high kinetic energies. experiment was performed GSI (Darmstadt), where combined use inverse kinematics technique with an efficient detection setup allowed us measure atomic number two fragments in coincidence. This measurement permitted obtain precision partial cross...
Intermediate energy single-neutron removal from 31Mg has been employed to investigate the transition into N=20 island of inversion. Levels up 5 MeV excitation in 30Mg were populated and spin-parity assignments inferred corresponding longitudinal momentum distributions γ-ray decay scheme. Comparison with eikonal-model calculations also permitted spectroscopic factors be deduced. Surprisingly, 02+ level was found have a strength much weaker than expected conventional picture predominantly...
Background: To understand explosive hydrogen burning in stars and to explore various scenarios such as type I x-ray bursts (XRBs), reliable reaction rates are needed. The cross sections for radiative proton capture on near-dripline nuclei necessary the determination of rates, but cannot be measured directly.Purpose: determine rate ${}^{23}\mathrm{Al}{(p,\ensuremath{\gamma})}^{24}\mathrm{Si}$ using indirect methods and, a consequence, evaluate if sequential $2p$ ${}^{22}$Mg seed is...
Light charged particles emitted in proton-induced fission reactions on $^{208}\mathrm{Pb}$ have been measured at different kinetic energies: $370A,\phantom{\rule{0.16em}{0ex}}500A$, and $650A$ MeV. The experiment was performed by the SOFIA Collaboration GSI facilities Darmstadt (Germany). inverse kinematics technique combined with a setup especially designed to measure light coincidence fragments. This measurement allowed us, for first time, obtain correlations between during process charge...
Fission is an extremely complex mechanism that requires a dynamical approach to describe the evolution of process in terms intrinsic and collective excitations nuclear constituents. In order determine these effects experimental setup was mounted at GSI, which allowed us for first time full identification charge mass all fission fragments thanks magnetic separation use inverse kinematic technique. Moreover, we also measured neutron multiplicities light-charged particles emitted coincidence...
The reaction 20 O ( d , t ) has been studied in inverse kinematics using a secondary radioactive beam produced with the SPIRAL facility at GANIL. Fragments, light charged particles and gamma rays were measured TIARA, MUST2, VAMOS EXOGAM detectors preliminary results are reported. level scheme of 19 is built spin parity one state tentatively assigned one-neutron transfer angular distribution.
Among the variety of crystal calorimeters recently designed for several physics facilities, CALIFA (CALorimeter In-Flight emitted gAmmas and light-charged particles) has especially demanding requirements since it must perform within a very complicated energy domain (gamma-ray energies from 0.1 to 20 MeV up 300 protons). As part R&D program Barrel section CALIFA, reduced geometry prototype was constructed. This consisted 3 × 5 array CsI(Tl) crystals varying dimensions, coupled large area...
Proton-induced fission of 208Pb has been investigated at 370, 500 and 650 A MeV in complete kinematic measurements. The experiment was performed GSI Darmstadt where the combined use inverse kinematics technique with an efficient detection setup allowed to measure for first time atomic mass number both fragments. measurement together different model calculations allow us investigate dissipative transient effects process dependence on temperature deformation dissipation strength β. spallation...
Within this paper we will present an entirely new energy reconstruction method iPhos for charged particles detected in CsI(Tl) crystals. Based on pulse shape analysis of scintillation signals [1] protons that cannot be stopped within the active detector material can distinguished from those fully stopped. Due to a special signature punch-through protons, they identified and their full is reconstructed specific loss. In dedicated experiment at Cyclotron Center Bronowice, Krakow first proof...
The spectroscopy of 21O has been investigated using a radioactive 20O beam and the (d,p) reaction in inverse kinematics. ground first excited states have determined to be Jpi=5/2+ Jpi=1/2+ respectively. Two neutron unbound were observed at excitation energies 4.76 +- 0.10 6.16 0.11. spectroscopic factor deduced for lower these interpreted as 3/2+ level, reveals rather pure 0d3/2 single-particle configuration. large energy difference between 1/2+ is indicative emergence N=16 magic number. For...