S. S. Ntshangase
A5053453134- 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
- Particle physics theoretical and experimental studies
- Advanced NMR Techniques and Applications
- X-ray Spectroscopy and Fluorescence Analysis
- Nuclear reactor physics and engineering
- Rare-earth and actinide compounds
- Superconducting Materials and Applications
- Neutrino Physics Research
- Advanced ceramic materials synthesis
- Astro and Planetary Science
- Radiation Detection and Scintillator Technologies
- Radiation Therapy and Dosimetry
- Cold Fusion and Nuclear Reactions
- Global Health Workforce Issues
- Health and Medical Research Impacts
- Plasma Diagnostics and Applications
- Hydrogen Storage and Materials
- Silicon Carbide Semiconductor Technologies
- Electron and X-Ray Spectroscopy Techniques
- Ion-surface interactions and analysis
University of Zululand
2014-2024
University of Warsaw
2024
National Centre for Nuclear Research
2024
Stellenbosch University
2022
Shandong University
2019
University of Cape Town
2008-2016
National Research Foundation
2013-2016
iThemba Laboratory
2005-2014
University of the Western Cape
2005
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.
The nature of the chiral candidate bands in $^{106}\mathrm{Ag}$, one only two known examples candidates which actually cross, is investigated experimentally and theoretically. Lifetimes have been determined for these $^{106}\mathrm{Ag}$ using Doppler-shift attenuation method with $\ensuremath{\gamma}$-detector array AFRODITE. level scheme has extended, three negative-parity observed to high spins. Configurations were assigned based on a quasiparticle alignment analysis configuration-fixed...
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.
A brief survey of results studies nuclear chirality in the mass 80 and 190 region at iThemba LABS is given, before looking case 106 Ag detail. Here, crossing a pair candidate chiral bands re-interpreted as prolate band by an aligned four-quasiparticle band.
Most important for the identification of chiral symmetry in atomic nuclei is to establish a pair bands that are near-degenerate energy, but also B(M1) and B(E2) transition probabilities. Dedicated lifetime measurements were performed four 194Tl, including four-quasiparticle with close near-degeneracy, considered as prime candidate best pair. The confirm excellent near-degeneracy this indicate third band may be involved scenario.
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 $^{82}\mathrm{Br}$.
Abstract This work reports the first rotational bands observed in neutron-deficient nucleus $$^{231}$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow/> <mml:mn>231</mml:mn> </mml:msup> </mml:math> U. Excited states were populated $$^{232}$$ <mml:mn>232</mml:mn> Th( $$\alpha $$ <mml:mi>α</mml:mi> ,5n) reaction at a beam energy of 52 MeV. Coincident decay $$\gamma <mml:mi>γ</mml:mi> -rays measured with high-purity germanium detectors afrodite spectrometer array,...
A search for isomeric states was performed in the nucleus ${}_{60}^{140}{\mathrm{Nd}}_{80}$ using in-beam \ensuremath{\gamma}-ray spectroscopy and $^{126}\mathrm{Te}$($^{18}\mathrm{O}$,$4n$) reaction. Prompt delayed coincidences were measured with AFRODITE spectrometer pulsed beam delivered by Separated Sector Cyclotron of iThemba LABS. One new isomer identified, spin-parity ${I}^{\ensuremath{\pi}}={20}^{+}$ lifetime ${T}_{1/2}\ensuremath{\ge}400$ ns, at an excitation energy ${E}_{x}=7430$...
The nuclei $^{230}\mathrm{U}$ and $^{232}\mathrm{U}$ were populated in the compound nucleus reactions $^{232}\mathrm{Th}$($\ensuremath{\alpha},6n$) $^{232}\mathrm{Th}$($\ensuremath{\alpha},4n$), respectively. Gamma rays from these observed coincidence with a recoil detector. A comprehensive set of in-band $E2$ transitions lowest lying negative-parity band while one transition was also for $^{230}\mathrm{U}$. These allowed...
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...
Analyzing powers have been measured for the $^{40}\mathrm{Ca}$($\stackrel{\ensuremath{\rightarrow}}{p},p\ensuremath{\alpha}$)$^{36}\mathrm{Ar}$ reaction at an incident energy of 100 MeV coplanar scattering angles corresponding to zero recoil momentum residual nucleus. Predictions based on distorted wave impulse approximation fail reproduce data.
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...
A summary of recent results research at iThemba LABS is given. This includes high-resolution measurements the fine structure isoscalar giant quadrupole resonances, a new programme to measure fusion barrier distributions for reactions leading formation superheavy elements, high-energy γ-rays from (p,y) using AFRODITE array HpGe clover detectors, and comparison vibrational band structures 160 Yb, measured with array, X(5)-β 2n model. future developments
We used the 8$\pi$ $\gamma$-ray spectrometer at TRIUMF-ISAC radiocative ion beam facility to obtain high-precision branching ratios for $^{19}$Ne $\beta^+$ decay excited states in $^{19}$F. Together with other previous work, our measurements determine superallowed $1/2^+ \to 1/2^+$ beta branch ground state $^{19}$F be 99.9878(7)\%, which is three times more precise than known previously. The implications of these testing a variety weak interaction symmetries are discussed briefly.
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...
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 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...
Background: Nuclei approaching $N=Z=40$ are known to exhibit strongly deformed structures and thought be candidates for shape coexistence. In the krypton isotopes, $^{80,82}\mathrm{Kr}$ poorly characterized, preventing an understanding of evolving deformation $N=40$.Purpose: The present work aims determine electric quadrupole transition strengths moments in order better characterize their deformation.Methods: Sub-barrier Coulomb excitation was employed, impinging isotopes on...
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...