T. D. Bucher
A5008052009- Nuclear physics research studies
- Atomic and Molecular Physics
- Nuclear Physics and Applications
- Advanced Chemical Physics Studies
- Astronomical and nuclear sciences
- Quantum Chromodynamics and Particle Interactions
- Rare-earth and actinide compounds
- Advanced NMR Techniques and Applications
- Radiation Detection and Scintillator Technologies
- Gamma-ray bursts and supernovae
- X-ray Spectroscopy and Fluorescence Analysis
- International Science and Diplomacy
- Nuclear reactor physics and engineering
- Crystal Structures and Properties
- Neutrino Physics Research
- Atomic and Subatomic Physics Research
- Chemical Thermodynamics and Molecular Structure
- Pulsars and Gravitational Waves Research
- Soybean genetics and cultivation
- X-ray Diffraction in Crystallography
- Astrophysical Phenomena and Observations
- Plant Pathogens and Resistance
- Potato Plant Research
- Bluetooth and Wireless Communication Technologies
- Particle accelerators and beam dynamics
iThemba Laboratory
2013-2024
National Research Foundation
2013-2024
Stellenbosch University
2015-2024
University of the Western Cape
2021-2022
University of Zululand
2021
Shandong University
2019
Two pairs of positive-and negative-parity doublet bands together with eight strong electric dipole transitions linking their yrast positive- and have been identified in ^{78}Br. They are interpreted as multiple chiral octupole correlations, which is supported by the microscopic multidimensionally-constrained covariant density functional theory triaxial particle rotor model calculations. This observation reports first example geometry soft nuclei.
Three ΔI=1 bands with the πg_{9/2}⊗νg_{9/2} configuration have been identified in _{35}^{74}Br_{39}. Angular distribution, linear polarization, and lifetime measurements were performed to determine multipolarity, type, mixing ratio, absolute transition probability of transitions. By comparing these experimental observations corresponding fingerprints quantum particle rotor model calculations, second third lowest are, respectively, suggested as chiral partner one-phonon wobbling excitation...
We have optimized the optical model potential (OMP) parameters for nucleon (protons and neutrons) induced reaction on 40Ca using OPTMAN code available RIPL-3 data library. The potentials, geometrical nuclear deformation were extracted via fitting angular distribution proton/neutron elastic inelastic scattering (Ep,n = 0 – 200 MeV) taken from EXFOR Our results demonstrate improvement in prediction of cross sections compared to Koning-Delaroche OMP. have, then, calculated γ-ray production most...
Two nearly degenerate positive-parity bands with the πg9/22⊗νg9/2−1 configuration and three negative-parity πg9/2(p3/2,f5/2)⊗νg9/2−1 have been identified in 81Kr. They are interpreted as chiral doublet pseudospin-chiral triplet bands, which is supported by constrained covariant density functional theory multiparticle plus rotor model calculations. The present work reports two new configurations πg9/2(p3/2,f5/2)⊗νg9/2−1, first example of involving π(p3/2,f5/2) pseudospin doublet.
Abstract The $$\gamma $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mi>γ</mml:mi></mml:math> -ray strength function ( SF) and nuclear level density (NLD) have been extracted for the first time from inverse kinematic reactions with Oslo method. This novel technique allows measurements of these properties across a wide range previously inaccessible nuclei. Proton– coincidence events $$\mathrm {d}(^{86}\mathrm {Kr}, \mathrm {p}\gamma )^{87}\mathrm {Kr}$$...
Isospin properties of dipole excitations in 74 Ge are investigated using the ({\alpha},{\alpha}'{\gamma}) reaction and compared to ({\gamma},{\gamma}) data. The results indicate that energy region 6 9 MeV adhere scenario recently found splitting into two separated parts: one at low energy, being populated by both isoscalar isovector probes, other high excited only electromagnetic probe. Relativistic quasiparticle time blocking approximation (RQTBA) calculations show a reduction E1 strength...
A comprehensive systematic study is made for the collective β and γ bands in even-even isotopes with neutron numbers N=88 to 92 proton Z=62(Sm) 70 (Yb). Data, including excitation energies, B(E0) B(E2) values, branching ratios from previously published experiments are collated new data presented first time this study. The experimental compared calculations using a five-dimensional Hamiltonian (5DCH) based on covariant density functional theory (CDFT). realistic potential quadrupole shape...
A pair of nearly degenerate positive-parity bands were observed in $^{82}\mathrm{Br}$ for the first time using $^{82}\mathrm{Se}(\ensuremath{\alpha},p3n)$ reaction. The doublet are proposed to be chiral based on triaxial particle rotor model and potential energy surface calculations. root-mean-square values angular momentum components their probability distributions discussed detail exhibit geometry its evolution $^{82}\mathrm{Br}$.
The spectroscopy of $^{71}\mathrm{Ge}$ has been investigated via the fusion-evaporation reaction $^{74}\mathrm{Ge}(\ensuremath{\alpha},\ensuremath{\alpha}3n)^{71}\mathrm{Ge}$. Collective structures including a rotational band built on $15/{2}^{\ensuremath{-}}$ octupole state in have established. observation strong $E1$ transitions and well-behaved sequence provide first experimental evidence an Ge isotopes, suggesting enhanced correlation around $N=40$ $A\ensuremath{\approx}70$ region. A...
The spectroscopy of $^{76}\mathrm{Se}$ has been studied using the $^{70}\mathrm{Zn}(^{12}\mathrm{C}, \ensuremath{\alpha}2{\mathrm{n})}^{76}\mathrm{Se}$ fusion evaporation reaction. yrast band extended to substantially higher spin, allowing observation second crossing. much-delayed ${g}_{9/2}$ proton-pair alignment is discussed in terms cranked shell model and most likely caused by a shape transition from prolate oblate along line occurring $^{76}\mathrm{Se}$. Based on systematic...
High-spin states in $^{74}\mathrm{As}$ were studied using the $^{74}\mathrm{Ge}(^{4}\mathrm{He},1p3n)$ reaction at beam energies of 58.6 and 62.6 MeV. Two positive- one negative-parity bands have been identified $^{74}\mathrm{As}$. The two positive-parity are interpreted as chiral doublet bands, which is supported by triaxial particle rotor model. Three electric dipole transitions linking yrast also observed this work, suggesting existence octupole correlations
Excited states in 98Ru were investigated using γ-ray spectroscopy following the β-decay of 98Rh, and via 100Ru(p,t) reaction. Combining results from two experiments, revised to have spin-parity 4+ subsequently assigned 02+ "γ" bands, respectively. The observed structures are suggested be deformed rotational, rather than spherical vibrational, fit well into systematics these excitations Ru isotopes. excitation is as a shape coexisting configuration. This observation eliminates some last...
The spectroscopy of $^{79}\mathrm{Se}$ is studied via the $^{82}\mathrm{Se}(\ensuremath{\alpha}$, $\ensuremath{\alpha}3n$)$^{79}\mathrm{Se}$ fusion-evaporation reaction. A negative-parity magnetic dipole band in established for first time. Based on calculations by self-consistent tilted axis cranking covariant density functional theory, this new can be classified as a ``stapler'' band, which has relatively stable symmetric prolate deformation function rotational frequency. Hence, it...
The spectroscopy of 62Cu is studied via the 54Cr(12C,1p3n)62Cu fusion-evaporation reaction. On basis γ−γ coincidence analysis, angular distributions from oriented states, and linear polarization measurement, three positive-parity negative-parity level sequences in are observed, including two new γ-ray transitions one level. collective structures discussed terms tilted axis cranking covariant density functional theory. Although not firmly confirmed experiment, properties a magnetic rotational...
High-spin states in $^{193}\mathrm{Tl}$ were studied and the level scheme was revised extended including observation of new rotational bands. A surprising competition between bands built on same $\ensuremath{\pi}{h}_{9/2}\ensuremath{\bigotimes}\ensuremath{\nu}{{i}_{13/2}}^{\ensuremath{-}2}$ nucleon configurations is observed. It suggested that it generated by two different modes this triaxial nucleus: (i) a rotation around intermediate nuclear axis, producing pair chiral symmetry bands, (ii)...
The modeling of nuclear $\ensuremath{\gamma}$-ray line emission induced by highly accelerated particles in astrophysical sites (e.g., solar flares, the gas and dust inner galaxy) comparison with observed emissions from these needs a comprehensive database related production cross sections. most important reactions protons $\ensuremath{\alpha}$ are those abundant target elements like C, O, N, Ne, Mg, Si, Fe at projectile energies extending reaction threshold to few hundred MeV per nucleon. In...
Rotational structures have been measured using the Jurogam II and GAMMASPHERE arrays at low spin following $^{155}\mathrm{Gd}(\ensuremath{\alpha},2n)^{157}\mathrm{Dy}$ $^{148}\mathrm{Nd}(^{12}\mathrm{C},5n)^{155}\mathrm{Dy}$ reactions 25 65 MeV, respectively. We report high-$K$ bands, which are conjectured to be first candidates of a ${K}^{\ensuremath{\pi}}={2}^{+}\ensuremath{\gamma}$ vibrational band, built on $[505]11/{2}^{\ensuremath{-}}$ neutron orbital, in both...
Reaching new depths in nuclear structure investigations requires experimental equipment and techniques of data analysis. The modern γ-ray spectrometers, like AGATA GRETINA are now built new-generation segmented germanium detectors. These most advanced detectors able to reconstruct the trajectory a inside detector. powerful detectors, but they need careful characterization, since their output signals more complex. For instance for each interaction that occurs segment such detector additional...
High-spin states in $^{155}\mathrm{Yb}$ have been studied via the $^{144}\mathrm{Sm}(^{16}\mathrm{O},5n)^{155}\mathrm{Yb}$ reaction at a beam energy of 118 MeV. One negative-parity and one positive-parity cascade built on $\ensuremath{\nu}{f}_{7/2}$ $\ensuremath{\nu}{i}_{13/2}$ states, respectively, are established for first time. The structures observed compared with those neighboring $N=85$ isotones semiempirical shell-model (SESM) calculations. According to adiabatic configuration-fixed...
High-spin states in 76As have been observed for the first time by using 4He+74Ge reaction at beam energies of 58.6 and 62.6 MeV. Two positive-parity three negative-parity bands found 76As. The two with πg9/2⊗νg9/2 configurations are tentatively interpreted as chiral doublet bands, which supported triaxial particle rotor model calculations. electric dipole transitions linking yrast positive- also this work, implying possible presence octupole correlations 76As.Received 29 July 2023Accepted 23...
Background: $\ensuremath{\gamma}$-ray spectroscopy studies of the Sn isotopes provide important information on nuclear structure and shell evolution across long isotopic chain between doubly-magic $^{100}\mathrm{Sn}$ $^{132}\mathrm{Sn}$ nuclei. These also offer great value to test tune models which can then be applied other regions chart.Purpose: We aim expand level scheme $^{118}\mathrm{Sn}$ by populating low-spin states in range 3--5 MeV determine their angular momentum for possible...