I. Pohjalainen
A5089752562- Nuclear physics research studies
- Nuclear Physics and Applications
- Atomic and Molecular Physics
- Astronomical and nuclear sciences
- Nuclear reactor physics and engineering
- Neutrino Physics Research
- Particle physics theoretical and experimental studies
- Mass Spectrometry Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Nuclear Materials and Properties
- Quantum Chromodynamics and Particle Interactions
- Advanced Chemical Physics Studies
- Radioactive element chemistry and processing
- Radiation Detection and Scintillator Technologies
- Astro and Planetary Science
- Radioactive contamination and transfer
- Particle accelerators and beam dynamics
- Ion-surface interactions and analysis
- Atomic and Subatomic Physics Research
- Spectroscopy and Laser Applications
- Particle Detector Development and Performance
- Laser Design and Applications
- Scientific Measurement and Uncertainty Evaluation
- Superconducting Materials and Applications
- Rare-earth and actinide compounds
University of Jyväskylä
2016-2025
GSI Helmholtz Centre for Heavy Ion Research
2022-2024
University of Liverpool
2023
Nantes Université
2022
Institut National de Physique Nucléaire et de Physique des Particules
2022
Centre National de la Recherche Scientifique
2022
IMT Atlantique
2022
Universitat de València
2019-2020
Instituto de Física Corpuscular
2019-2020
Brookhaven National Laboratory
2017
Precision mass measurements of neutron-rich rhodium isotopes have been performed at the JYFLTRAP Penning trap spectrometer Ion Guide Isotope Separator On-Line (IGISOL) facility. We report results on ground- and isomeric-state masses in $^{110,112,114,116,118}\mathrm{Rh}$ very first measurement $^{120}\mathrm{Rh}$. The isomeric states were separated measured for time using phase-imaging ion-cyclotron-resonance (PI-ICR) technique. For $^{112}\mathrm{Rh}$, we also new half-lives both ground...
The rare-earth peak in the $r$-process abundance pattern depends sensitively on both astrophysical conditions and subtle changes nuclear structure region. This work takes an important step elucidating reducing uncertainties calculations via precise atomic mass measurements at JYFLTRAP double Penning trap. $^{158}$Nd, $^{160}$Pm, $^{162}$Sm, $^{164-166}$Gd have been measured for first time precisions $^{156}$Nd, $^{158}$Pm, $^{162,163}$Eu, $^{163}$Gd, $^{164}$Tb improved considerably. Nuclear...
Mass measurements of fission and projectile fragments, produced via $^{238}\mathrm{U}$ $^{124}\mathrm{Xe}$ primary beams, have been performed with the multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS) Fragment Separator (FRS) Ion Catcher a resolving power (FWHM) up to 410 000 an uncertainty down $6\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}8}$. The nuclides were separated in flight fragment separator FRS at 300 1000 MeV/u thermalized cryogenic stopping cell....
High-precision mass measurements of exotic ^{95-97}Ag isotopes close to the N=Z line have been conducted with JYFLTRAP double Penning trap spectrometer, silver ions produced using recently commissioned inductively heated hot cavity catcher laser ion source at Ion Guide Isotope Separator On-Line facility. The atomic ^{95}Ag was directly determined for first time. In addition, masses β-decaying 2^{+} and 8^{+} states in ^{96}Ag identified measured time, precision ^{97}Ag has improved. newly...
211Po ions in the ground and isomeric states were produced via 238U projectile fragmentation at 1000 MeV/u. The spatially separated flight from primary beam other reaction products by fragment separator FRS. energy-bunched, slowed-down thermalized a gas-filled cryogenic stopping cell (CSC). They then extracted CSC injected into high-resolution multiple-reflection time-of-flight mass spectrometer (MR-TOF-MS). excitation energy of isomer and, for first time, isomeric-to-ground state ratio...
Abstract Understanding the evolution of nuclear charge radius is one long-standing challenges for theory. Recently, density functional theory calculations utilizing Fayans functionals have successfully reproduced radii a variety exotic isotopes. However, difficulties in isotope production hindered testing these models immediate region chart below heaviest self-conjugate doubly-magic nucleus 100 Sn, where near-equal number protons ( Z ) and neutrons N lead to enhanced neutron-proton pairing....
The impact of nuclear deformation can been seen in the systematics charge radii, with radii generally expanding increasing deformation. In this Letter, we present a detailed analysis precise relationship between quadrupole and size. Our approach combines first measurements changes mean-square well-deformed palladium isotopes A=98 A=118 density functional calculations using Fayans functionals, specifically Fy(std) Fy(Δr,HFB), UNEDF2 functional. are extracted from collinear laser spectroscopy...
A novel system has been developed to detect simultaneous double-alpha emission from purified and weightless sources. The includes the collection of 224Ra low-energy recoils in helium buffer gas decay 228Th. recoil products are thermalized collected a cryogenic cell extracted into an RF-ion guide for mass selection. mass-separated ions implanted at low kinetic energy thin carbon foil placed between two large-area double-sided silicon strip detectors observe correlated alpha-particle emission....
The multinucleon transfer (MNT) reaction approach was successfully employed for the first time to measure isomeric ratios (IRs) of 211Po isomer (25/2+) and its ground state (9/2+) at IGISOL facility using a 945 MeV 136Xe beam impinged on 209Bi natPb targets. dominant production isomers compared corresponding states consistently revealed in α-decay spectra. Deduced IR populated through 136Xe+natPb found have an enhancement ≈1.8-times than that observed 136Xe+209Bi. State-of-the-art...
We report on high-precision atomic mass measurements of ^{148-153}La and ^{151}Ce performed with the JYFLTRAP double Penning trap using phase-imaging ion-cyclotron-resonance technique. The masses ^{152,153}La were experimentally determined for first time. confirm sharp kink in two-neutron separation energies at neutron number N=93 cerium (Z=58) isotopic chain. Our precision most exotic neutron-rich lanthanum (Z=57) isotopes reveal a unexpected sudden increase from N=92 to N=93. Unlike chain,...
The <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mi>β</a:mi></a:math>-delayed neutron emission in the <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"><b:mrow><b:mmultiscripts><b:mi>As</b:mi><b:mprescripts/><b:none/><b:mrow><b:mn>85</b:mn><b:mo>,</b:mo><b:mn>86</b:mn></b:mrow></b:mmultiscripts><b:mspace width="4pt"/><b:mi>β</b:mi></b:mrow></b:math> decays has been measured at Ion Guide Isotope Separator On Line facility of Accelerator Laboratory University Jyväskylä. complete...
Even mass neutron-rich niobium isotopes are among the principal contributors to reactor antineutrino energy spectrum. They also most challenging measure due refractory nature of niobium, and because they exhibit isomeric states lying very close in energy. The β-intensity distributions Nb100gs,100m Nb102gs,102m β decays have been determined using total absorption γ-ray spectroscopy technique. measurements were performed at upgraded Ion Guide Isotope Separator On-Line facility University...
Collinear laser spectroscopy was performed on the isomer of aluminium isotope ^{26m}Al. The measured shift to ^{27}Al in 3s^{2}3p ^{2}P_{3/2}^{○}→3s^{2}4s ^{2}S_{1/2} atomic transition enabled first experimental determination nuclear charge radius ^{26m}Al, resulting R_{c}=3.130(15) fm. This differs by 4.5 standard deviations from extrapolated value used calculate isospin-symmetry breaking corrections superallowed β decay Its corrected Ft value, important for estimation V_{ud}...
Isomers close to doubly magic Ni502878 provide essential information on the shell evolution and shape coexistence near Z=28 N=50 double closure. We report excitation energy measurement of 1/2+ isomer in Zn493079 through independent high-precision mass measurements with JYFLTRAP Penning trap ISOLTRAP multi-reflection time-of-flight spectrometer. unambiguously place at 942(10) keV, slightly below 5/2+ state 983(3) keV. With use state-of-the-art shell-model diagonalizations, complemented...
The atomic mass relations among the triplet $^{96}\mathrm{Zr}$, $^{96}\mathrm{Nb}$, and $^{96}\mathrm{Mo}$ have been determined by means of high-precision measurements using JYFLTRAP spectrometer at IGISOL facility University Jyv\"askyl\"a. We report $Q$ values for $^{96}\mathrm{Zr}$ single double $\ensuremath{\beta}$ decays to $^{96}\mathrm{Nb}$ $^{96}\mathrm{Mo}$, as well value decay which are ${Q}_{\ensuremath{\beta}}(^{96}\mathrm{Zr})=163.96(13)$,...
Isomeric states in $^{128}$In and $^{130}$In have been studied with the JYFLTRAP Penning trap at IGISOL facility. By employing novel ion manipulation techniques, different were separated masses of six beta-decaying measured. was also used to select ions interest for identification a post-trap decay spectroscopy station. A new high-spin isomer feeding $15^-$ $^{128}$Sn has discovered $1797.6(20)$ keV. Shell-model calculations CD-Bonn potential re-normalized perturbative G-matrix approach...
The $\ensuremath{\beta}$ decays of the ground state (gs) and isomeric $(m)$ $^{96}\mathrm{Y}$ have been studied with total absorption $\ensuremath{\gamma}$-ray spectroscopy technique at Ion Guide Isotope Separator On-Line facility. separation ${8}^{+}$ from ${0}^{\ensuremath{-}}$ was achieved thanks to purification capabilities JYFLTRAP double Penning trap system. $\ensuremath{\beta}$-intensity distributions both independently determined. In analyses deexcitation 1581.6 keV level in...
We report on a set of high-precision measurements nuclear binding and excitation energies, as well spins, magnetic dipole electric quadrupole moments neutron-rich silver isotopes, 113−123Ag. The were performed using the JYFLTRAP mass spectrometer collinear laser spectroscopy beamline at Ion Guide Isotope Separator On-Line (IGISOL) facility. For first time, we can firmly establish ordering long-lived Iπ=1/2−,7/2+ states in these pin down inversion two levels either A=121(N=74) or A=123(N=76)....
We report on precision mass measurements of $^{113,115,117}\mathrm{Ru}$ performed with the JYFLTRAP double Penning trap spectrometer at Accelerator Laboratory University Jyv\"askyl\"a. The phase-imaging ion-cyclotron-resonance technique was used to resolve ground and isomeric states in $^{113,115}\mathrm{Ru}$ enabled for first time a measurement isomer excitation energies, ${E}_{x}(^{113}\mathrm{Ru}^{\mathrm{m}})=100.5(8)$ keV ${E}_{x}(^{115}\mathrm{Ru}^{\mathrm{m}})=129(5)$ keV. state...
Long-lived isotopes of plutonium were studied using two complementary techniques, high-resolution resonance ionization spectroscopy (HR-RIS) and collinear laser (CLS). Isotope shifts have been measured on the $5{f}^{6}7{s}^{2}{\phantom{\rule{4pt}{0ex}}}^{7}{F}_{0}\ensuremath{\rightarrow}5{f}^{5}6{d}^{2}7s\phantom{\rule{4pt}{0ex}}(J=1)$ $5{f}^{6}7{s}^{2}{\phantom{\rule{4pt}{0ex}}}^{7}{F}_{1}\ensuremath{\rightarrow}5{f}^{6}7s7p\phantom{\rule{4pt}{0ex}}(J=2)$ atomic transitions HR-RIS method...
We report the first experimental determination of independent isomeric yield ratios using direct ion counting with a Penning trap, which offered such high resolution in mass that states could be separated. The measurements were performed at Ion Guide Isotope Separator On-Line (IGISOL) facility University Jyv\"askyl\"a. isomer production $^{81}\mathrm{Ge}$, $^{96,97}\mathrm{Y}$, $^{128,130}\mathrm{Sn}$, and $^{129}\mathrm{Sb}$ 25-MeV proton-induced fission $^{\mathrm{nat}}\mathrm{U}$...