SAIP 2011 Report of Contributions https://events.saip.org.za/e/saip2011 SAIP 2011 / Report of Contributions Defects and Reconstructions in El … Contribution ID: 2 Type: Poster Presentation Defects and Reconstructions in Electron Beam Irradiated Graphene Sheets Wednesday, 13 July 2011 17:00 (2 hours) <p>Graphene characterization and device fabrication often require extensive use of the scanning electron microscopy (SEM) and tunneling electron microscopy (TEM). These techniques involve electron beam irradiation that usually causes defects in materials under investigation. The radia- tion induced defects may lead to significant damage to the material which may alter its properties, normally an undesirable phenomenon. However, recent experiments show that electron radiation can have beneficial effects in materials. Graphenic materials have the ability to reorganize their structures under irradiation like no other materials. This property can find application in radiation hard electronics owing to the technological importance of graphenic materials. Here we report the Raman and scanning tunneling microscopy (STM) results of pristine and heat treated electron -beam irradiated graphene sheets (mono-layer and double layers) to demonstrate graphenic recon- structions. STM creates images of the charge density of electrons at the Fermi level such that all surface atoms can be visible. Level (Hons, MSc, <br>   PhD, other)? PhD Consider for a student <br>   award (Yes / No)? Yes Would you like to <br> submit a short paper <br> for the Conference <br> Pro- ceedings (Yes / No)? No Primary author: Mr FABIANE, Mopeli (University of Pretoria PhD Student) Presenter: Mr FABIANE, Mopeli (University of Pretoria PhD Student) Session Classification: Poster1 Track Classification: Track A - Condensed Matter Physics and Material Science October 2, 2021 Page 1 SAIP 2011 / Report of Contributions Simulating chorus generation via … Contribution ID: 3 Type: Poster Presentation Simulating chorus generation via Particle-in-cell simulations Thursday, 14 July 2011 17:00 (2 hours) <p>Chorus emissions are whistler mode waves propagating through the Earth’s magnetosphere in two distinct frequency bands, typically in the range of 0.1-0.8 fce, where fce is the equatorial electron gyro-frequency. Chorus consists of discrete elements, which are normally rising tones, each of which lasts for a few tenths of a second. Chorus is predominantly observed during the onset of the substorm expansion phase when energetic electrons are injected into the magnetosphere. As these electrons drift eastward around towards noon, their distribution becomes unstable tothe amplifiation of whistler mode waves. It is thought that the amplification process proceeds viathe Doppler-shifted cyclotron resonance interaction. Particle-in-cell (PIC) simulations, which simulate the motion of groups of similar particles on a two dimensional grid subject to the self-consistent electric and magnetic fields generated by their spatial distribution and motion, are used to simulate the amplification of whistler-mode waves propagating along the magnetic field. A population of electrons having a velocity distribution with a thermal anisotropy is injected into the plasma and the growth of the resulting waves is investigated. Level (Hons, MSc, <br>   PhD, other)? PhD Consider for a student <br>   award (Yes / No)? Yes Would you like to <br> submit a short paper <br> for the Conference <br> Pro- ceedings (Yes / No)? No Primary author: Mr KOEN, Etienne (Hermanus Magnetic Observatory) Co-authors: Dr COLLIER, Andrew (University of KwaZulu Natal); Ms VAN ZYL, Marlie (University of KwaZulu Natal); Dr MAHARAJ, Shimul (Hermanus Magnetic Observatory) Presenter: Ms VAN ZYL, Marlie (University of KwaZulu Natal) Session Classification: Poster2 Track Classification: Track D2 - Space Science October 2, 2021 Page 2 SAIP 2011 / Report of Contributions Numerical Field Analysis of the M … Contribution ID: 4 Type: Oral Presentation Numerical Field Analysis of the Magnets for a proposed Ionisation Beam Profile Monitor for High Current Synchrotron and Cooler Rings. Friday, 15 July 2011 11:15 (15 minutes) <p>iThemba LABS was requested by the Institut für Kernphysik at Forschungszentrum Jülich, Germany, to design and calculate a magnet system for a proposed non-destructive Ionization Beam Profile Monitor (IBPM) that can measure beam profiles using the secondary ions produced inthe rest gas, planned to be implemented with the FAIR-GSI project in Darmstadt Apart from the geometrical restrictions by the available space, the main requirements for the mag- net system are to comply with the specified field intensity and homogeneity at the plane ofmea- surement and to deliver the primary beam unchanged and aligned with the original beam direction within the GSI storage ring. The calculated magnets for the IBPM consists of four window-frame, room-temperature, water- cooled, laminated, dipole DC-electromagnets in line with the primary beam. The inner two dipoles of the set are respectively used for horizontal and vertical beam profile analysis and the correct delivery of the beam from the system is facilitated with the aid of two corrector magnets. The magnets are mounted outside and around the vacuum chamber that contains other essential com- ponents and therefore will have unusually large pole gaps that are in the order of 0.5 m, which, together with the relative short drift lengths between the magnets, cause significant interference between the magnetic flux distributions of the magnets. This necessitated the use of 3D numerical field analysis that incorporates al the magnets. The field homogeneities in the regions where the beam profiles are to be measured werefoundto be very sensitive to the magnet geometries and layout, but a workable solution was found and the calculated results of these magnets and multi-pole and ion beam optics analysis of the system will be presented. Level (Hons, MSc, <br>   PhD, other)? All Consider for a student <br>   award (Yes / No)? No Would you like to <br> submit a short paper <br> for the Conference <br> Pro- ceedings (Yes / No)? No Primary author: Dr DE VILLIERS, John Garrett (iThemba LABS) Co-authors: Mr BOEHME, Christian (IKP, FZ-Jülich); Dr CONRADIE, J. L. (iThemba LABS); Prof. October 2, 2021 Page 3 SAIP 2011 / Report of Contributions Numerical Field Analysis of the M … DIETRICH, Jürgen (IKP, FZ-Jülich); Dr FORCK, Peter (GSI, Darmstadt); Mr GIACOMINI, T (GSI, Darm- stadt); Dr KAMERDZHIEV, Vsevolod (IKP, FZ-Jülich) Presenter: Dr DE VILLIERS, John Garrett (iThemba LABS) Session Classification: Applied Track Classification: Track F - Applied and Industrial Physics October 2, 2021 Page 4 SAIP 2011 / Report of Contributions PLASMON: Data Assimilation of t … Contribution ID: 5 Type: Poster Presentation PLASMON: Data Assimilation of the Earth’s Plasmasphere Thursday, 14 July 2011 17:00 (2 hours) <p>The principal source and loss mechanisms in the Earth’s radiation belts are currently notcom- pletely understood. Loss rates are important since they determine the duration of exposure of satellites to enhanced radiation conditions during a geomagnetic storm. The dominant loss pro- cess is relativistic electron precipitation via resonant interactions with a variety of wave modes. These interactions are governed by the characteristics of the plasmasphere. Current models pro- vide an inadequate representation of the spatial and temporal evolution of the plasmasphere. In situ measurements of the plasmasphere provide only local characteristics and are thus unable to yield a complete global picture. Ground based measurements, based on the analysis of Very Low Frequency (VLF) whistlers and Field Line Resonances (FLRs), are able to describe large sections of the plasmasphere, extending over significant radial distances and many hours of local time. These measurements provide electron number and plasma mass densities. PLASMON is a funded FP7 project between 11 international partners. PLASMON intends to assim- ilate near real time measurements of plasmaspheric densities into a dynamic plasmasphere model. The VLF whistler analyses will be conducted by automatic retrieval of equatorial electron densities using data from AWDAnet. Equatorial mass densities will be constructed from FLR measurements along meridional magnetometer chains. The resulting model will facilitate the prediction ofpre- cipitation rates. The predicted rates will be compared to observations from the AARDDVARK network. Level (Hons, MSc, <br>   PhD, other)? Other. Consider for a student <br>   award (Yes / No)? No. Would you like to <br> submit a short paper <br> for the Conference <br> Pro- ceedings (Yes / No)? No. Primary author: COLLIER, Andrew (Hermanus Magnetic Observatory) Co-authors: JORGENSEN, Anders (New Mexico Institute of Mining and Technology); HEILIG, Balázs (Eötvös Loránd Geophysical Institute); HOLZWORTH, Bob (University of Washington); RODGER, Craig (University of Otago); REDA, Jan (Institute of Geophysics, Polish Academy of Sciences); MAN- NINEN, Jyrki (University of Oulu); LICHTENBERGER, János (Eötvös Loránd University); CLILVERD, Mark (British Antarctic Survey); VELLANTE, Massimo (University of L’Aquila); FRIEDEL, Reiner (Los Alamos National Laboratory) October 2, 2021 Page 5 SAIP 2011 / Report of Contributions PLASMON: Data Assimilation of t … Presenter: COLLIER, Andrew (Hermanus Magnetic Observatory) Session Classification: Poster2 Track Classification: Track D2 - Space Science October 2,