Shane Carelse

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First Production Run at the New Tandetron Facility

Sulphur material is notoriously known to evaporate rapidly under the effect of ion beam irradiation, and for this reason sulphur targets are seldom used. The first production run at the new Tandetron facility was performed to test a new target making approach. The element is encapsulated in between extremely thin Mylar material and beam is constantly swiveled onto the pocket. The method proves to be effective with as little as 1mg of initial material. This is particularly interesting when dealing with the expensive 36S isotope.

The demise of the largest and oldest African baobabs

The paper “The demise of the largest and oldest African baobabs”, by Adrian Patrut, Stephan Woodborne, Roxana T Patrut, Laszlo Rakosy, Daniel A Lowy, Grant Hall, Karl F von Reden, published in Nature Plants, Volume 4, 423-426 (2018) was ranked #66/100 globally for its news value, and #21 when compared with papers of the same age. Coverage of the Baobab climate change project was shown on CNN in December 2018 (https://edition.cnn.com/2018/12/31/africa/baobab-trees-are-dying-climate-change-intl/index.html).

Successful Measurements with the Tape Station

2018 has seen two experiments run on the tape station, the PhD project of Lucky Makhathini. Long ago, the Nobel Prize winners Aage Bohr and Ben Mottelson solved the Schrodinger equation for the atomic nucleus. They predicted that the nucleus could vibrate in certain ways. But is this really true? Both experiments were trying to answer this question. The goal of Lucky’s experiment was to look for evidence that what we thought was a vibrating nucleus was really the nucleus changing into a rugby ball shape. The other experiment was proposed by a visitor from the University of Guelph, Canada, Professor Paul Garrett. Professor Garrett was delighted with the “fantastic results” which identified g-ray transitions in 98Ru – key to deciding whether or not 98Ru is a vibrator. The tape station is one of the first pieces of experimental apparatus to be developed for use in the LERIB project.

Picture: Professor Paul Garrett, Lucky Makhathini and Rob Bark posing in front of the tape station

Electron Spectrometer Commissioned

The electron spectrometer project was successfully commissioned in October, a little later than expected than July when the device faced several severe problems in its first tests. The hard work of the “One iThemba” team from Subatomic physics, Instrumentation and IT, and Accelerator departments, all rallied around to fix the device allowing it to take first beam at iThemba LABS. The commissioning aims to study electric monopole (E0) transitions in 70Ge, and is the subject of PhD candidate Mr Abraham Avaa of Wits / iThemba LABS.

Photo: From top left clockwise: Mr M Chisapi setting the spectrometer, first in-beam plot of electron energy versus magnetic field, Mr Avaa and Msebi loading targets, Mr Avaa only weeks away from beam time with the open spectrometer, the “One iThemba” team coming together after a successful commissioning.

THE SAINTS@tlabs: PHYSICS SUMMER SCHOOL 2019

The annual student summer school at iThemba LABS commenced on Thursday the 10th of January with in attendance 24 students representing a total of ten HEI’s (Higher Education institutions) from across the country. Organized under the training umbrella of SAINTS (Southern African Institute of Nuclear Technology and Sciences), the iThemba LABS annual summer school does not only offer experiential hands-on training  for students across a wide range of  Accelerator Based Science and related SET (Science Engineering and  Technology) fields, but is also used as a precursor from where a limited number of students are selected on merit to participate at the SA-JINR Practice Summer school which is held in June at the JINR laboratories in Dubna, Russia.  The current iThemba LABS Student Summer School lasts for three weeks, and is scheduled to end on Tuesday the 29th January 2019.  In addition to lectures given by the iThemba LABS staff, the summer school also drew lecturers from partnering academic institutions, viz UCT, UWC, and Stellenbosch University.   Three lecturers from the JINR also contributed to the summer school program.

Exploring the Secrets of Deformed Nuclei

The first K600 experiment for 2018 was performed at the beginning of June. The experiment, performed with 200 MeV protons, provided excellent data for a study of a particular vibrational mode of deformed Samarium nuclei. The local team was joined by scientists and students from the universities of Stellenbosch, the Western Cape, WITS and Zululand, as well as from further afield such as Botswana (BIUST) and Germany (TUD). While some experimental and beam-related challenges were experienced during the first of two extended beam periods, the experiment was successfully concluded with a very stable and good-quality beam in the second five-day beam period.

Towards the Construction of the Most Powerful Microscope Using Particle Accelerators

Prof Bruce Mellado

About 500 physicists gathered in Amsterdam, Holland, in April to discuss the prospects for this new more powerful accelerator. Prof Bruce Mellado was invited to give a plenary talk at the opening day, attended by the Director General of CERN and other leading members of the High Energy Physics community internationally. Prof Mellado discussed the possibility of attaching a small accelerator of electrons for head on collisions with the protons and heavy Ions of the FCC, which is referred to as the FCC-he option.

Russian Visit

The Accelerator Department recently hosted two Ion Source physicists, Dr Sergey Bogomolov and Dr Andrey Efremov, from the Joint Institute for Nuclear Research in Dubna, Russia, to collaborate on a project aimed at producing lithium ion beam from the external electron cyclotron resonance ion source (ECRIS). During the research visit, lithium ions, produced inside the ECRIS by means of the oven method were extracted, and ran stable for several hours.

New Collaboration In Africa

Mathis Wiedeking and Peane Maleka visited colleagues at the University of Dar es Salaam (UDSM) in Tanzania to finalize discussions on collaborative projects and on a formal agreement between the two institutes.  The physics group at UDSM includes applied nuclear physics and material science and mutual research interests which are aligned with projects that are ongoing at iThemba LABS on environmental radiation, neutron activation and X-ray diffraction were identified. Agreement was also reached for a Memorandum of Understanding between UDSM and iThemba LABS.

Picture from left: Prof Lyimo (Principal (Dean) of the College of Natural and Applied Science), Dr Maleka, Dr Kassim (HoD Physics Department UDSM), Dr Wiedeking

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