A. Goldkuhle
A5068338027- Nuclear physics research studies
- Nuclear Physics and Applications
- Advanced Chemical Physics Studies
- Astronomical and nuclear sciences
- Atomic and Molecular Physics
- Atomic and Subatomic Physics Research
- Particle physics theoretical and experimental studies
- Advanced NMR Techniques and Applications
- Quantum Chromodynamics and Particle Interactions
- Neutrino Physics Research
- X-ray Spectroscopy and Fluorescence Analysis
- Radiation Detection and Scintillator Technologies
- Chemical Thermodynamics and Molecular Structure
- Inorganic Fluorides and Related Compounds
- Nuclear reactor physics and engineering
- Rare-earth and actinide compounds
- Welding Techniques and Residual Stresses
- Advanced Measurement and Metrology Techniques
- Ion-surface interactions and analysis
- Magnetic Properties of Alloys
- Sensor Technology and Measurement Systems
- Chalcogenide Semiconductor Thin Films
- Isotope Analysis in Ecology
- Advanced MRI Techniques and Applications
- Scientific Research and Discoveries
University of Cologne
2017-2024
There is sparse direct experimental evidence that atomic nuclei can exhibit stable "pear" shapes arising from strong octupole correlations. In order to investigate the nature of collectivity in radium isotopes, electric (E3) matrix elements have been determined for transitions ^{222,228}Ra using method sub-barrier, multistep Coulomb excitation. Beams radioactive isotopes were provided by HIE-ISOLDE facility at CERN. The observed pattern E3 different nuclear explained describing ^{222}Ra as...
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,...
To test the predictive power of ab initio nuclear structure theory, lifetime second 2+ state in neutron-rich 20O, tau(2+_2 ) = 150(+80-30) fs, and an estimate for 16C have been obtained, first time. The results were achieved via a novel Monte Carlo technique that allowed us to measure lifetimes tens-to-hundreds femtoseconds range, by analyzing Doppler-shifted gamma-transition line shapes products low-energy transfer deep-inelastic processes reaction 18O (7.0 MeV/u) + 181Ta. requested...
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,...
The lifetime of the ${2}_{1}^{+}$ state $^{212}\mathrm{Po}$ was measured in $^{208}\mathrm{Pb}$($^{12}\mathrm{C},^{8}\mathrm{Be}$)$^{212}\mathrm{Po}$ transfer reaction by $\ensuremath{\gamma}$-ray spectroscopy employing recoil distance Doppler shift (RDDS) method. derived absolute $B(E2)$ value 2.6(3) W.u. indicates a low collectivity and contradicts previous claims $\ensuremath{\alpha}$-cluster components structure state. It is demonstrated that consistent description properties...
Lifetimes of the excited states in neutron-rich $^{52,54}\mathrm{Ti}$ nuclei, produced a multinucleon-transfer reaction, were measured by employing Cologne plunger device and recoil-distance Doppler-shift method. The experiment was performed at Grand Acc\'el\'erateur National d'Ions Lourds facility using Advanced Gamma Tracking Array for $\ensuremath{\gamma}$-ray detection, coupled to large-acceptance variable mode spectrometer an event-by-event particle identification. A comparison between...
The nature of quadrupole and octupole collectivity in $^{222}\mathrm{Rn}$ was investigated by determining the electric-quadrupole ($E2$) ($E3$) matrix elements using subbarrier, multistep Coulomb excitation. radioactive beam, accelerated to 4.23 MeV/u, provided HIE-ISOLDE facility at CERN. Data were collected Miniball $\ensuremath{\gamma}$-ray spectrometer following bombardment two targets, $^{120}\mathrm{Sn}$ $^{60}\mathrm{Ni}$. Transition $E2$ within ground-state bands measured up...
There is a large body of evidence that atomic nuclei can undergo octupole distortion and assume the shape pear. This phenomenon important for measurements electric-dipole moments atoms, which would indicate CP violation hence probe physics beyond Standard Model particle physics. Isotopes both radon radium have been identified as candidates such measurements. Here, we observed low-lying quantum states in 224Rn 226Rn by accelerating beams these radioactive nuclei. We show isotopes vibrations...
Lifetimes of low-lying yrast states in $^{162}\mathrm{Er}$ are measured using the electronic $\ensuremath{\gamma}\text{\ensuremath{-}}\ensuremath{\gamma}$ fast-timing technique. Excited were populated a $^{154}\mathrm{Sm}(^{12}\mathrm{C},4n)^{162}\mathrm{Er}$ fusion-evaporation reaction and $\ensuremath{\gamma}$ rays detected combined setup high purity germanium ${\mathrm{LaBr}}_{3}$(Ce) scintillation detectors. The lifetimes ${4}_{1}^{+}$ ${6}_{1}^{+}$ determined for first time...
Lifetime measurements of excited states in 178Hg have been performed using the 103Rh(78Kr,p2n) reaction at a beam energy 354 MeV. The recoil-decay tagging (RDT) technique was applied to select nuclei and associate prompt γ rays with correlated characteristic ground-state α decay. Lifetimes four lowest yrast determined recoil distance Doppler-shift (RDDS) method. experimental data are compared theoretical predictions focus on shape coexistence. results confirm shift deformed prolate...
We would like to make readers aware that after the publication of this article sort code was updated.This resulted in more gamma-gamma data, particularly for high-spin transitions.By performing additional analysis we confirm energies most states, have identified several new and updated one states incorrectly represented its energy original paper.The figures (Figs. 1234) table (Table 1) are along with their captions.The overall conclusions paper remain unaffected.The data our finding, 224,226...
Abstract A novel Monte Carlo technique has been developed to determine lifetimes of excited states in the tens-to-hundreds femtoseconds range products low-energy heavy-ion binary reactions, with complex velocity distributions. The method is based on a detailed study Doppler-broadened $$\gamma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>γ</mml:mi> </mml:math> -ray lineshapes. Its relevance demonstrated connection $$^{18}\text {O}(7.0\, \text {MeV/u})+\,^{181}\text...
High-resolution $\ensuremath{\gamma}$-ray spectroscopy of $^{18}\mathrm{N}$ is performed with the Advanced GAmma Tracking Array, following deep-inelastic processes induced by an $^{18}\mathrm{O}$ beam on a $^{181}\mathrm{Ta}$ target. Six states are newly identified, which together three known excitations exhaust all negative-parity excited expected in below neutron threshold. Spin and parities proposed for located basis decay branchings comparison large-scale shell-model calculations p-sd...
Lifetimes of the $T=1$ isobaric analog ${I}^{\ensuremath{\pi}}={2}^{+}$ states in $^{50}\mathrm{Mn}$ and $^{50}\mathrm{Cr}$ were measured simultaneously by employing recoil distance Doppler-shift (RDDS) technique. The populated a fusion-evaporation reaction with $^{12}\mathrm{C}$ beam on $^{40}\mathrm{Ca}$ target. An analysis data calculations from present work, together available $B(E2:{2}^{+}\ensuremath{\rightarrow}{0}^{+})$ $^{50}\mathrm{Fe}$ $^{50}\mathrm{Cr}$, used to study isospin...
A lifetime measurement of excited states in $^{144}\mathrm{Ce}$ using the $^{142}\mathrm{Ce}(^{18}\mathrm{O},^{16}\mathrm{O})$ reaction with a beam energy 67 MeV and recoil distance Doppler-shift method was performed at Cologne FN Tandem accelerator. Lifetimes three lowest yrast have been measured as well for ${3}_{1}^{\ensuremath{-}}$ state an effective ${4}_{2}^{+}$ state. Reduced $E2$ transition strengths determined these results compared to predictions from recent shell-model...
Level lifetimes of the yrast $(5/{2}^{\ensuremath{-}})$ to $13/{2}^{\ensuremath{-}}$ states in neutron-rich nucleus $^{53}\mathrm{Ti}$, produced a multinucleon-transfer reaction, have been measured for first time. The recoil distance Doppler-shift method was employed and excited were extracted by lineshape analysis aided Geant4-based Monte-Carlo simulations. experiment performed at Grand Acc\'el\'erateur National d'Ions Lourds facility Caen, France, using Advanced Gamma Tracking Array...
The lifetimes of the 21+ and 41+ states Po208 were measured in α-transfer reaction Pb204(C12,Be8)Po208 by γ-ray spectroscopy utilizing recoil distance Doppler shift method. newly extracted transition strengths alongside ones decay 22+ state compared to results large-scale shell-model calculations using an effective interaction derived from realistic CD-Bonn nucleon-nucleon potential. comparison indicates importance quadrupole isovector excitations valence shell for a fine tuning two-body...
Lifetimes of excited nuclear states were determined in $^{44}\mathrm{Ti}$ using the recoil distance Doppler-shift technique and attenuation method. Results from ${K}^{\ensuremath{\pi}}={3}^{\ensuremath{-}}$ band confirm isospin-symmetry breaking for ${3}_{1}^{\ensuremath{-}}\ensuremath{\rightarrow}{2}_{1}^{+}\phantom{\rule{4pt}{0ex}}E1$ transition. The lifetime ${4}_{1}^{\ensuremath{-}}$ state differs considerably previously known value. Good agreement is found ${4}_{1}^{+}$ ${6}_{1}^{+}$...
A recoil-distance Doppler shift experiment has been performed using the $^{102}\mathrm{Pd}(^{19}\mathrm{F},p2n$) reaction at a beam energy of 73 MeV to measure lifetime excited states in $^{118}\mathrm{Xe}$. The differential decay-curve method $\ensuremath{\gamma}\ensuremath{\gamma}$ coincidences and gating procedure that allows extract without feeding assumptions employed. lifetimes obtained for yrast up spin-parity ${8}^{+}$ are compared with interacting boson model calculations...
During the AGATA campaign at GANIL, neutron-deficient Sn region was populated via a multi-nucleon transfer reaction in order to directly measure lifetime of first excited states with plunger device, providing complementary information previous results obtained Coulomb excitation experiments.The γ-ray array used together VAMOS++ spectrometer study nuclei interest.
A new method of extracting the γ-ray intensities necessary to perform lifetime measurements using differential decay curve (DDCM) is presented in this work, unresolved Doppler-shifted components (UDCM). The UDCM allows for a DDCM analysis be performed transition which fully and degraded are unresolvable energy so detected as single peak. This technique was used measure known yrast 21+ state 50Mn with depopulating that does not have resolvable components. measured through applying consistent...