Department of Physics

Radon-222 measurements at Cape Point : a characterization of a 15-year time series

Botha, R.; Labuschagne, C.; Williams, A. G.; Bosman, G.; Brunke, E.-G.; Rossouw, A.; Lindsay, R. (National Association for Clean Air, 2018)

Radon-222 measurements at Cape Point: A characterization of a 15-year time series The Cape Point (CPT) Global Atmosphere Watch (GAW) research station have been monitoring climatically significant trace ...

Vacuum polarization energy of the Shifman–Voloshin soliton

Weigel, H.; Graham, N. (Elsevier, 2018)

We compute the vacuum polarization energy of soliton configurations in a model with two scalar fields in one space dimension using spectral methods. The second field represents an extension of the conventional ϕ4 kink ...

Spin symmetry in the Dirac sea derived from the bare nucleon–nucleon interaction

Shen, Shihang; Liang, Haozhao; Meng, Jie; Ring, Peter; Zhang, Shuangquan (Elsevier, 2018)

The spin symmetry in the Dirac sea has been investigated with relativistic Brueckner–Hartree–Fock theory using the bare nucleon–nucleon interaction. Taking the nucleus 16O as an example and comparing the theoretical results ...

Effects of tensor forces in nuclear spin–orbit splittings from ab initio calculations

Shen, Shihang; Liang, Haozhao; Meng, Jie; Ring, Peter; Zhang, Shuangquan (Elsevier, 2018)

A systematic and specific pattern due to the effects of the tensor forces is found in the evolution of spin–orbit splittings in neutron drops. This result is obtained from relativistic Brueckner–Hartree–Fock theory using ...

Multiple chiral doublets in four-j shells particle rotor model : five possible chiral doublets in ¹³⁶₆₀Nd₇₆

Chen, Q. B.; Lv, B. F.; Petrache, C. M.; Meng, Jie (Elsevier, 2018)

A particle rotor model, which couples nucleons in four single-jshells to a triaxial rotor core, is developed to investigate the five pairs of nearly degenerate doublet bands recently reported in the even-even nucleus 136Nd. ...

Wavelet signatures of K-splitting of the Isoscalar Giant Quadrupole Resonance in deformed nuclei from high-resolution (p, p ) scattering off ¹⁴⁶,¹⁴⁸,¹⁵⁰Nd

Kureba, C. O.; Buthelezi, Z.; Carter, J.; Cooper, G. R. J.; Fearick, R. W.; Fortsch, S. V.; Jingo, M.; Kleinig, W.; Krugmann, A.; Krumbolz, A. M.; Kvasil, J.; Mabiala, Justin; Mira, J. P.; Nesterenko, V. O.; Von Neumann-Cosel, P.; Neveling, R.; Papka, P.; Reinhard, P. G.; Richter, A.; Sideras-Haddad, E.; Smit, F. D.; Steync, G. F.; Swartz, J. A.; Tamii, A.; Usman, I. T. (Elsevier, 2018)

The phenomenon of fine structure of the Isoscalar Giant Quadrupole Resonance (ISGQR) has been studied with high energy-resolution proton inelastic scattering at iThemba LABS in the chain of stable even-mass Nd isotopes ...

Chiral geometry and rotational structure for ¹³⁰Cs in the projected shell model

Chen, F. Q.; Meng, Jie; Zhang, S. Q. (Elsevier, 2018)

The projected shell model with configuration mixing for nuclear chirality is developed and applied to the observed rotational bands in the chiral nucleus 130Cs. For the chiral bands, the energy spectra and electromagnetic ...

Neutron-rich nuclei produced at zero degrees in damped collisions induced by a beam of ¹⁸O on a ²³⁸U target

Stefan, I.; Fornal, B.; Leoni, S.; Azaiez, F.; Portail, C.; Thomas, J. C.; Karpovi, A. V.; Ackermann, D.; Bednarczyk, P.; Blumenfeld, Y.; Calinescu, S.; Chbihi, A.; Ciemala, M.; Cieplicka-Orynczak, N.; Crespi, F. C. L.; Franchoo, S.; Hammache, F.; Iskr, L. W.; Jacquote, B.; Janssens, R. V. F.; Kamalou, O.; Lewitowicz, M.; Olivier, L.; Lukyanov, S. M.; Maccormick, M.; Maj, A.; Marini, P.; Matea, I; Naumenko, M. A.; De Oliveira Santos, F.; Petrone, C.; Penionzhkevich, Yu E.; Rotaru, F.; Savajols, H.; Sorline, O.; Stanoiu, M.; Szpak, B.; Tarasov, O. B.; Verney, D. (Elsevier, 2018)

Cross sections and corresponding momentum distributions have been measured for the first time at zero degrees for the exotic nuclei obtained from a beam of 18O at 8.5 MeV/A impinging on a 1 mg/cm2238U target. Sizable cross ...

Deformation dependence of the isovector giant dipole resonance : the neodymium isotopic chain revisited

Donaldson, L. M.; Bertulani, C. A.; Carter, J.; Nesterenko, V. O.; Von Neumann-Cosel, P.; Neveling, R.; Ponomarev, V. Yu; Reinhard, P. G.; Usman, I. T.; Adsley, P.; Brummer, J. W.; Buthelezi, E. Z.; Cooper, G. R. J.; Fearick, R. W.; Fortsch, S. V.; Fujita, H.; Fujita, Y.; Jingo, M.; Kleinig, W.; Kureba, C. O.; Kvasil, J.; Latif, M.; Li, K. C. W.; Mira, J. P.; Nemulodi, F.; Papka, P.; Pellegri, L.; Pietralla, N.; Richter, A.; Sideras-Haddad, E.; Smit, F. D.; Steyn, G. F.; Swartz, J. A.; Tamii, A. (Elsevier, 2018)

Proton inelastic scattering experiments at energy Ep=200MeV and a spectrometer scattering angle of 0° were performed on 144,146,148,150Nd and 152Sm exciting the IsoVector Giant Dipole Resonance (IVGDR). Comparison with ...

Investigation of four carbon monoxide isotopomers in natural abundance by laser-induced fluorescence in a supersonic jet

Du Plessis, Anton; Rohwer, Erich G.; Steenkamp, Christine M. (Elsevier, 2007)

The four carbon monoxide (CO) isotopomers 12C16O, 13C16O, 12C18O and 12C17O have been detected simultaneously in a CO gas sample of natural isotopic abundance by measuring rovibronic excitation spectra of six vibronic bands ...

Accurate Laboratory Wavelengths of the A1Π(υ' = 0-5)-X1Σ+(υ'' = 0) Vibronic Bands of 12C17O and 12C18O

Du Plessis, Anton; Rohwer, Erich G.; Steenkamp, Christine M. (IOP Science, 2006)

Twenty nine rovibronic lines of 12C17O for which laboratory wavelengths were previously unavailable were detected in laser-induced fluorescence excitation spectra of the six vibronic bands A1Π(υ' = 0-5)-X1Σ+(υ'' = 0). ...

Accurate laboratory wavelengths of the e 3 Σ–(ν' = 5) – X 1 Σ+(ν'' = 0) band of 12C16O

Dickenson, G. D.; Nortje, A. C.; Steenkamp, C. M.; Rohwer, E. G.; Du Plessis, A. (IOP Science, 2010)

The forbidden singlet-triplet transitions of carbon monoxide (CO) are important in the interpretation of vacuum ultraviolet interstellar absorption spectra and in particular for the measurement of large CO column densities. ...

Free charge carrier absorption in silicon at 800 nm

Heisel, P.-C.; Ndebeka, W. I.; Neethling, P. H.; Paa, W.; Rohwer, E. G.; Steenkamp, C. M.; Stafast, H. (Springer, 2016)

The transmission of a Ti:sapphire laser beam (c.w. and fs pulsed operation at 800 nm) through a 10-μm-thin oxidized silicon membrane at 45° angle of incidence at first increases with the incident laser power, then shows a ...

Implementation of an Ytterbium 171 Trapped Ion Qubit

Matjelo, Naleli Jubert (Stellenbosch : Stellenbosch University., 2020-04)

ENGLISH ABSTRACT: This thesis presents the work done in developing an ion trap lab at Stellenbosch University. A linear Paul trap was assembled under a microscope and geometrically veriﬁed using a laserbeam and a translational ...

A ghostly tail of the Hoyle state and its breathing-mode excitation

Li, Kevin Ching Wei (Stellenbosch : Stellenbosch University., 2020-04)

ENGLISH ABSTRACT: 12C is almost exclusively produced in stars from a combination of 4He and unstable 8Be which form an excited three-alpha resonance named the Hoyle state, located just above the 3α separation energy at Ex ...

Evidence estimation using stochastic likelihood approximations

Cameron, Scott (Stellenbosch : Stellenbosch University., 2020-04)

ENGLISH ABSTRACT: We consider the problem of estimating evidence for parametric Bayesian models in the large data regime. Many existing evidence estimation algorithms scale poorly due to their need to repeatedly calculate ...

Design, construction and characterisation of a low-level radioactivity counting system based on gamma-ray spectrometry with LaBr3:Ce scintillator detectors

Bashir, Munirat (Stellenbosch : Stellenbosch University., 2020-04)

ENGLISH ABSTRACT: The activity concentrations in naturally occurring radioactive material (NORM) samples are conventionally measured using a gamma-ray spectrometer with a single detector (mostly HPGe or NaI:Tl) enclosed ...