U. Jakobsson
A5033553141- Nuclear physics research studies
- Atomic and Molecular Physics
- Astronomical and nuclear sciences
- Nuclear Physics and Applications
- Advanced Chemical Physics Studies
- Quantum Chromodynamics and Particle Interactions
- Rare-earth and actinide compounds
- Advanced NMR Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Astro and Planetary Science
- Nuclear reactor physics and engineering
- Quantum, superfluid, helium dynamics
- Radioactive Decay and Measurement Techniques
- Particle accelerators and beam dynamics
- Particle physics theoretical and experimental studies
- Laser-induced spectroscopy and plasma
- Inorganic Fluorides and Related Compounds
- Scientific Research and Discoveries
- Electron and X-Ray Spectroscopy Techniques
- Mass Spectrometry Techniques and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Subatomic Physics Research
- Nanowire Synthesis and Applications
- Silicon Nanostructures and Photoluminescence
- Radioactivity and Radon Measurements
University of Jyväskylä
2014-2025
University of Helsinki
2015-2022
Helsinki Institute of Physics
2013-2022
KTH Royal Institute of Technology
2011-2021
Warsaw University of Technology
2017
Niğde Ömer Halisdemir Üniversitesi
2017
AlbaNova
2015-2017
University of York
2011-2016
University of Manchester
2011-2012
Istanbul University
2011
The rotational band structure of the Z=104 nucleus (256)Rf has been observed up to a tentative spin 20ℏ using state-of-the-art γ-ray spectroscopic techniques. This represents first such measurement in superheavy whose stability is entirely derived from shell-correction energy. properties are compared those neighboring nuclei and it shown that kinematic dynamic moments inertia sensitive underlying single-particle shell specific location high-j orbitals. therefore provide test pairing which...
Abstract The $$\upalpha $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>α</mml:mi> </mml:math> -decay fine structure of $$^{179}$$ <mml:mmultiscripts> <mml:mrow/> <mml:mn>179</mml:mn> </mml:mmultiscripts> Hg and $$^{177}$$ <mml:mn>177</mml:mn> Au was studied by means decay spectroscopy. Two experiments were performed at the Accelerator Laboratory University Jyväskylä (JYFL), Finland, utilizing recoil separator RITU a digital data acquisition system. heavy-ion induced...
Very neutron deficient francium isotopes have been produced in fusion evaporation reactions using ${}^{60}$Ni ions on ${}^{141}$Pr targets. The gas-filled recoil separator RITU was employed to collect the products and separate them from scattered beam. activities were implanted into a position sensitive silicon detector after passing through gas-counter system. identified spatial time correlations between implants decays. Two $\ensuremath{\alpha}$-particle activities, with...
Coulomb-excitation experiments are performed with postaccelerated beams of neutron-deficient $^{196,198,200,202}\mathrm{Po}$ isotopes at the REX-ISOLDE facility. A set matrix elements, coupling low-lying states in these isotopes, is extracted. In two heaviest $^{200,202}\mathrm{Po}$, transitional and diagonal elements ${2}_{1}^{+}$ state determined. $^{196,198}\mathrm{Po}$ multistep Coulomb excitation observed, populating ${4}_{1}^{+},\phantom{\rule{0.28em}{0ex}}{0}_{2}^{+}$, ${2}_{2}^{+}$...
The level scheme of the neutron-deficient nuclide $^{168}\mathrm{Os}$ has been extended and mean lifetimes excited states have measured by recoil distance Doppler-shift method using JUROGAM $\ensuremath{\gamma}$-ray spectrometer in conjunction with IKP K\"oln plunger device. $^{168}\mathrm{Os}\phantom{\rule{4pt}{0ex}}\ensuremath{\gamma}$ rays were delayed coincidence recoiling fusion-evaporation residues detected at focal plane RITU gas-filled separator. ratio reduced transition...
The rotational band structure of $^{255}\mathrm{Lr}$ has been investigated using advanced in-beam $\ensuremath{\gamma}$-ray spectroscopic techniques. To date, is the heaviest nucleus to be studied in this manner. One unambiguously observed and strong evidence for a second was found. structures are tentatively assigned based on $1/{2}^{\ensuremath{-}}[521]$ $7/{2}^{\ensuremath{-}}[514]$ Nilsson states, consistent with assignments from recently obtained $\ensuremath{\alpha}$ decay data....
In this paper we investigate the rotational band built upon a two-quasiparticle ${8}^{\ensuremath{-}}$ isomeric state of ${}^{252}$No up to spin ${I}^{\ensuremath{\pi}}$ $=$ ${22}^{\ensuremath{-}}$. The excited states were populated with ${}^{206}$Pb(${}^{48}\text{Ca},2n$) fusion-evaporation reaction. An unambiguous assignment structure isomer as $7/{2}^{+}{[624]}_{\ensuremath{\nu}}\ensuremath{\bigotimes}9/{2}^{\ensuremath{-}}{[734]}_{\ensuremath{\nu}}$ configuration has been made on basis...
By exploiting the SAGE spectrometer a simultaneous measurement of conversion electrons and γ rays emitted in de-excitation excited levels neutron-deficient nuclei 184,186Hg was performed. The light Hg isotopes under investigation were produced using 4n channels fusion-evaporation reactions 40Ar 148,150Sm. measured K- L-conversion electron ratios confirmed stretched E2 nature several transitions yrast bands 184,186Hg. Additional information on E0 component 2+2→2+1 transition 186Hg...
Knowledge of the exact microscopic structure 01+ ground state and first excited 02+ in 150Sm is required to understand branching double β decay these states from 150Nd. The detailed spectroscopy 152Gd has been studied using (α,xn) reactions γ-ray arrays AFRODITE JUROGAM II. Consistently strong E1 transitions are observed between Kπ = bands lowest negative parity both nuclei. These results discussed terms possible permanent octupole deformation band also “tidal wave” model Frauendorf.Received...
The nucleus ${}^{203}$Fr has been studied through $\ensuremath{\gamma}$-ray and electron spectroscopy, using the recoil-decay tagging technique. A 13/2${}^{+}$ state, with a half-life of 0.37(5) $\ensuremath{\mu}$s, observed in ${}^{203}$Fr. Both $\ensuremath{\alpha}$-decay branch internal de-excitation 1/2${}^{+}$ isomer have studied. Furthermore, corresponding 0.31(8) s, found ${}^{199}$At. In addition, transitions feeding 9/2${}^{\ensuremath{-}}$ ground state identified. level pattern...
Decay spectroscopy of ${}^{250}$No, aided by digital pulse-shape analysis, is reported and identifies this nucleus to be one the rare breed very heavy nuclei with an isomeric state living considerably longer than its ground state. This phenomenon has interesting consequences for nuclear structure models aiming determine borders island stability superheavy elements.
The lifetimes of the low-lying excited states $2^+$ and $4^+$ have been directly measured in neutron-deficient $^{106,108}$Sn isotopes. nuclei were populated via a deep-inelastic reaction lifetime measurement was performed employing differential plunger device. emitted $\gamma$ rays detected by AGATA array, while products uniquely identified VAMOS++ magnetic spectrometer. Large-Scale Shell-Model calculations with realistic forces indicate that, independently pairing content interaction,...
Excited states in the extremely neutron-deficient nucleus Pb180 have been identified for first time using JUROGAM II array conjunction with RITU recoil separator at Accelerator Laboratory of University Jyväskylä. This study lies limit what is presently achievable in-beam spectroscopy, an estimated cross section only 10 nb Mo92(Zr90,2n)Pb180 reaction. A continuation trend observed Pb182 and Pb184 seen, where prolate minimum continues to rise beyond N=104 midshell respect spherical ground...
Lifetimes of excited states in the yrast band neutron-deficient nuclide $^{166}\mathrm{W}$ have been measured utilizing DPUNS plunger device at target position JUROGAM II $\ensuremath{\gamma}$-ray spectrometer conjunction with RITU gas-filled separator and GREAT focal-plane spectrometer. Excited were populated $^{92}\mathrm{Mo}(^{78}\mathrm{Kr},4p$) reaction a bombarding energy 380 MeV. The measurements reveal low value for ratio reduced transitions probabilities lowest-lying...
The triple α-decay chain 114Ba→110Xe→106Te→102Sn has been directly observed for the first time, following 58Ni(58Ni,2n) reaction. Implantation of 114Ba nuclei into a double-sided silicon-strip detector allowed their α decays to be correlated in position and time with daughter (110Xe) granddaughter (106Te) nuclei. In total, 17 events have assigned chain. energy decay measured Eα=3480(20) keV, which is 70 keV higher than previously value, half-life improved accuracy, 380+190−110 ms. A revised...
The nucleus ${}^{205}$Fr has been studied through $\ensuremath{\gamma}$-ray and electron spectroscopy using the recoil-decay tagging technique. resulting level scheme presents a spherical structure built on 9/2${}^{\ensuremath{-}}$ ground state rotational top of short-lived isomer. isomer, with spin parity 13/2${}^{+}$ half-life 80(20) ns, de-excites by an $M2$ transition directly to state. Another, longer-lived, 1.15(4) ms, also found assigned 1/2${}^{+}$. Transitions populating de-exciting...
The recoil-$\ensuremath{\beta}$ tagging technique was used to identify transitions associated with the decay of ${\mathrm{2}}^{+}$ and, tentatively, ${\mathrm{4}}^{+}$ excited states in $^{74}\mathrm{Sr}$. Combining these results published data for $A=74$ isobars, triplet energy differences (TEDs) have been extracted, heaviest case which values evaluated. State-of-the-art shell-model calculations using JUN45 interaction and incorporating a $J=0$ isospin nonconserving (INC) an isotensor...
The lifetime of the 2+→0g.s.+ transition in neutron-deficicient nucleus Te112 has been measured for first time using DPUNS plunger and recoil distance Doppler shift technique. deduced value reduced probability is B(E2:0g.s.+→2+)=0.46±0.04e2b2, indicating that there no unexpected enhancement B(E2:0g.s.+→2+) values Te isotopes below midshell. result compared to discussed framework large-scale shell-model calculations.Received 15 April 2015Revised 25 May...
The excited states of $^{201}\mathrm{At}$ were studied and an isomeric $29/{2}^{+}$ state $[{T}_{\textonehalf{}}=3.39(9)\phantom{\rule{0.28em}{0ex}}\ensuremath{\mu}\mathrm{s}]$ was identified by using a fusion-evaporation reaction, gas-filled recoil separator, gating techniques. is suggested to originate from the $\ensuremath{\pi}({h}_{9/2})\ensuremath{\bigotimes}|^{200}\mathrm{Po};{11}^{\ensuremath{-}}\ensuremath{\rangle}$ configuration, it decays through 269- 339-keV $E2$- $E3$-type...
The heaviest N=Z doubly-magic nucleus, $^{100}$Sn, and the neighboring nuclei offer unique opportunities to investigate properties of nuclear interaction in extreme conditions. In particular, Cd isotopes are expected present features similar those found Sn isotopic chain, since they have only two proton holes Z=50 shell. this manuscript, lifetime measurements low-lying states even-mass $^{102-108}$Cd is presented. Thanks powerful detection capabilities AGATA array VAMOS++ spectrometer,...