Advanced Nuclear Science and Technology Techniques Workshop

16 May 2022, 08:00 → 20 May 2022, 23:00 Africa/Johannesburg

Visitors Centre (NRF-iThemba LABS, Old Faure Road, Cape Town)

Lindsay Donaldson (iThemba Laboratory for Accelerator Based Sciences)

The 4th Advanced Nuclear Science and Technology Techniques (ANSTT4) workshop is scheduled to take place from 16 – 20 May 2022 at NRF-iThemba LABS, Cape Town.
The 5-day event will be offered as an in-person-event under strict COVID-19 protocol.

The focus will be on Metrology, Neutrons, Nuclear Structure, AMS, Environmental Measurements and Networking.  The ANSTT will make provision for the inclusion of  round table discussions aimed at providing updates on our inter-Africa and international collaborations from previous meetings. This follows on from the ANSTT series of meetings held in 2018, 2019 and 2021

Collaborations both UK-Africa and inter-Africa will again be at the forefront of the workshop, including Memoranda of Understanding.

The workshop offers a comprehensive programme of invited talks, accepted talks, poster presentations by students and round-table discussions

Participation (presentation and poster) is subject to abstracts being accepted by an advisory panel

For enquiries or further information, contact the Event Coordinator: Michelle van der Ventel-Bark on anstt2020@tlabs.ac.za

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Monday, 16 May

09:00 → 09:30 Registration

09:30 → 10:00 Welcome

Convener: Pete Jones (iThemba LABS)

09:30 Welcome

Speaker: Rudzani Nemutudi (iThemba LABS)

10:00 → 11:00 Accelerator Mass Spectrometry

Convener: Pete Jones (iThemba LABS)

10:00 Does Accelerator Mass Spectrometry have a place in an emerging economy?

South Africa’s science infrastructure is required to respond to a mandate that specifies a number of outcomes, and one of the core tenets is that science must impact on wellbeing in the country. Extremely expensive science platforms, such as the recently commissioned Accelerator Mass Spectrometry (AMS) facility at iThemba LABS, must respond by facilitating research for users; by training the next generation of scientists; and by leading cutting edge research with a local benefit. The AMS facility is the only one of its kind on the African continent and will grow to serve not only the South African science community, but also the wider African community until it has a continental footprint. In meeting the mandate the AMS facility must operate in a partnership with the user base, both in the provision of know-how to run analyses on a science agenda set by the users, but also in leading in-house research that accommodates academic partners and facilitates post-graduate student participation. Many of the societal benefits of AMS are not to be found in the particle physics domain, but rather in the applied science that falls in to other disciplines. The basis of these applications is in the systematics of rare element production, decay and distribution among different reservoirs. Scientists at iThemba LABS are partnering with users who require traditional chronology-based applications of AMS, but they are also using the AMS facility across a wide range of novel applied domains. These include: testing climate change forecasts, dating groundwater recharge, assessing global phenomenon such as magnetic field fluctuations over the last 50 000 years. The essence of the program is to use particle physics for the benefit of the people of South Africa, and Africa.

Speaker: Stephan Woodborne

11:00 → 11:30 Coffee Break | Group Photo

11:30 → 13:00 Metrology and Applications

11:30 NMISA Keynote Speaker

Speaker: Dr Wynand Louw (NMISA)

12:15 Update on NMISA radioactivity standards lab activities since 2020

An update on the NMISA RS lab activities since the start of 2020 will be provided. This comprises international comparisons of activity measurements using primary methods, participation in proficiency tests using gamma-spec and liquid scintillation counting, and low-level comparisons. An update on our scope of accreditation will also be provided and various types of client work that has been completed. Future plans will also be discussed.

Speaker: Milton van Rooy (NMISA)

13:00 → 14:00 Lunch

14:00 → 15:30 The MeASURe experience

Convener: Thomas Leadbeater (University of Cape Town)

14:00 MeASURe: the art and science of nuclear measurement at the University of Cape Town

The Metrological and Applied Sciences University Research Unit (MeASURe) was established in the Department of Physics at the University of Cape Town in 2018 to consolidate and expand research programs in applied nuclear physics, nanophysics, and measurement education and training. Integral to MeASURe is a robust understanding of reference standards, uncertainties, traceability, and how this translates into the development of novel measurement techniques to address real-world problems. Central to these activities is access to particle beams and radioisotopes through niche fast neutron facilities, proton therapy research beamline, and position emission particle tracking laboratories at the University of Cape Town and iThemba LABS.

We present the current state-of-the-art of neutron- and gamma ray-based research within MeASURe, including the development of detectors and instrumentation, advanced computation and stochastic modelling, and the applications of such measurements and techniques. A subset of current postgraduate students will present their research into modern fast neutron detector systems, positron emission particle tracking and prompt gamma ray imaging. Future avenues of research at MeASURe are explored with respect to the SDGs and potential impact to the African continent and beyond.

Speakers: Andy Buffler (UCT) , Ms Chloe Sole (University of Cape Town) , Mr Josiah De Klerk (University of Cape Town) , Mr Mike Van Heerden (University of Cpe Town) , Mr Robert Van der Merwe (University of Cape Town) , Prof. Steve Peterson (University of Cape Town) , Dr Tanya Hutton (University of Cape Town) , Dr Tom Leadbeater (University of Cape Town) , Dr Zina Ndabeni (University of Cape Town)

15:30 → 16:00 Tea Break

16:00 → 17:00 Function: Tour of iThemba LABS

17:00 → 18:00 Posters

18:00 → 20:00 Function: Welcome Function

Tuesday, 17 May

10:00 → 11:05 Environmental Applications

Convener: Innocent Jimmy Lugendo (University of Dar es Salaam)

10:00 Spectroscopic Systems: From research to applications

H C Boston, on behalf of the Nuclear Physics Group, Department of Physics, University of Liverpool, UK

The University of Liverpool Nuclear Physics research group has been involved in studying the structure of the nucleus at the frontiers of nuclear stability since its inception. To compliment these studies, and to push the boundaries of our knowledge we have been forefront at designing and implementing arrays to be used by the Nuclear Physics community.

The evolution of radioactive ion-beam facilities has necessitated a step change in both the sensitivity of the nuclear instrumentation and in the data analysis techniques used in these challenging experiments and campaigns to study novel and exciting nuclear phenomena.

The detection of gamma radiation is at the heart of nuclear structure physics experiments and is key to the success of many industrial and medical applications involving gamma ray imaging. Projects such as the Advanced Gamma Tracking Array (AGATA) in Europe and the Gamma-ray Energy Tracking Array (GRETA) in the United States have pushed the technical boundaries needed to realise spectrometers capable of measuring nuclei far from stability.

This presentation will focus on how the technology designed for Nuclear Physics experiments has found application in areas outside of the core physics programme. Sensors developed for Medical, Security, Environmental and Nuclear imaging systems will be presented and discussed.

Speaker: Helen Boston (University of Liverpool)

10:45 Design and construction of a gamma-ray spectrometer with water shielding for low-level natural occurring radioactive material measurement

Gamma-ray spectrometer with a single HPGe or NaI:Tl detector shielded with lead is often used to measure the activity concentration of radionuclides in soil samples. A passive water shield to reduce background radiation reaching the detectors was designed using GEANT4 Monte Carlo simulations and then constructed. IAEA-375 soil and beach sand each placed in Marinelli beaker were measured for 48 hours using two LaBr$_3$:Ce detectors placed inside the constructed water shield. The samples were also measured for 24 hours using a NaI:Tl detector inside the constructed water shield and HPGe shielded with lead and copper to compare and validate the results from measurements with the LaBr$_3$:Ce detectors. Both the simulated and measured results show that the water shield attenuates the 2614.5 keV gamma rays by over 90 % and energies lower than the 2614.5 keV by far above 90 %. The activity concentration of $^{40}$K radionuclide in IAEA-375 soil and beach sand measured using the LaBr$_3$:Ce detectors was below the minimum detectable activity (MDA) due to the internal activity of the detector. The measured activity concentrations of $^{238}$U and $^{232}$Th series and $^{40}$K radionuclides in IAEA-375 soil were comparable with certified values to within measurement uncertainties. The activity concentrations of $^{238}$U and $^{232}$Th series radionuclides in beach sand were determined using all the measurement geometries and consistent to within 1$\sigma$ to 2$\sigma$ level.

Speaker: Dr Munirat Bashir (Ibrahim Badamasi Babangida University, Lapai. Nigeria)

11:05 → 11:30 Coffee Break

11:30 → 12:00 Environmental Applications

Convener: Innocent Jimmy Lugendo (University of Dar es Salaam)

12:00 → 13:00 Neutron physics and applications

Convener: Milton van Rooy (US/iThemba LABS Student)

12:00 Magnetized dense neutron and neutron star matter

A neutron star is one of the possible end states of a massive star. It is compressed by gravity and stabilized by the nuclear degeneracy pressure. Despite its name, the composition of these objects are not exactly known. However, from the inferred densities, neutrons will most likely compose a significant fraction of the star’s interior. While all neutron stars are expected to have a magnetic field, some neutron stars ("magnetars") are much more highly magnetized than others: the inferred magnetar surface magnetic field is between $10^{14}$ to $10^{15}$ gauss.

Neutron stars are the densest stable states of matter that can currently be directly observed. Some neutron stars ("pulsars") emit strongly in the radio part of the electromagnetic spectrum. Observation of this radiation is one of the major observational targets of what will the world's largest radio telescope, the Square Kilometre Array.

While neutron stars are macroscopic objects, due to the extreme value of the stars' energy, pressure, and magnetic field the physics of the microscopic scale can be imprinted on the star's large scale behaviour. Thus the study of these objects are a combination of various fields of physics ranging from Quantum Mechanics to General Relativity. One of the main inputs to any calculation of neutron star properties is the equation of state of the matter that comprises the interior of the star.

This talk will focus on describing the thermodynamics of magnetized dense neutron and neutron star matter, its equation of state, and how the equation of state is applied to study observational consequences in neutron stars.

Speaker: Dr Jacobus Diener (Botswana International University of Science and Technology)

13:00 → 14:00 Lunch

14:00 → 14:50 Neutron physics and applications

Convener: Dr Milton van Rooy (NMISA)

14:30 Evaluation of Nuclear Radiation Damage on Lutetium-Aluminium for Practical Applications Using Neutron Irradiation Technique

Materials exposed to a high radiation environment such as a nuclear reactor, high energy collider systems or in space can gradually degrade and weaken. Studies on radiation damage have become necessary to ascertain which materials are capable of withstanding the stress of these extreme radiation environments. This study is based on the evaluation of neutron radiation damage in Lutetium-Aluminium (Lu-Al) looking at its possible usage in reactor technology and other sensitive extreme radiation environments. The study will employ fission nuclear reactor as the radiation field source to irradiate the material. Monte Carlo Simulation methods using MCNP are deployed to study the expected damage of the material due to neutron irradiation. Characterization of the sample material will be carried out pre and post irradiation with HRTEM and XRD. Measurements of the number of displacements per atom (dpa) which is an accepted measure for radiation damage will be discussed in order to ascertain the level of radiation damage to the microstructure of the material. Finally, characterization results of the material degradation as a result of the irradiation will be compared with the Monte Carlo simulated results.

Keywords: Radiation Damage, DPA, Monte Carlo Simulation, NAA.

Speaker: Mr Samuel Terungwa Temaugee (School of Physics, University of the Witwatersrand, Johannesburg, South Africa)

14:50 → 16:00 Discussion Session: Neutron Physics and Applications

Conveners: Helen Boston (University of Liverpool) , Thomas Leadbeater (University of Cape Town)

16:00 → 16:30 Tea Break

16:30 → 17:00 Posters

16:30 Level structure and transition multipolarities in 54Mn

Electromagnetic transition probabilities are of great interest to nuclear physicists as they provide detailed information about the nature of the wave functions of the initial and the final states. Odd-odd nuclei in the vicinity of Z = N = 20 and 28 shell closure present a unique opportunity for testing the underlying proton-neutron residual interaction. These nuclei exhibit a complex level structure due to many possible couplings of unpaired nucleons to the even-even core [1]. Hence, the investigation of their nuclear properties provides scope for understanding the single-particle energies and the residual neutron-neutron interactions in the shell model substructure [1,2]. The properties of the low and high spin states in odd-odd 54Mn (Z = 25, N = 29) have been studied [1-3] via different probes. Spectroscopic information such as -ray branching ratios, and multipole mixing ratios, were determined for transition energies, 54 keV up to 1509 keV (from J = 2+ up to 6+) [4,5]. The lifetimes of many states have been also measured [6]. In Kumar et al., [2], the excited states in 54Mn were populated using 51V(20Ne,xn,yp)54Mn reaction up to excitation energy of 5 MeV, = 15+. However, the information on the reduced transitions probabilities in 54Mn is still scarce despite numerous studies.

We shall report on the first conversion electron and electron-positron pair conversion study of 54Mn. Excited states up to 3 MeV have been populated in the 54Cr(p,n)54Mn reaction at 5.4 MeV bombarding energy, using DC beams from ANU Heavy Ion Accelerator Facility (HIAF). Internal Conversion Coefficients (ICC) for the low-lying states in 54Mn were determined in several transitions for the first time [6]. The deduced conversion coefficients allow for the assignment of multipolarities for transition energies > 1 MeV up to ~ 2.1 MeV ( = 1+ up to 4+). The results are compared with shell-model calculations as a test of agreement between theory and the experiment.

[1] S. Basu, et al., 64th DAE BRNS Symp. on Nucl. Phys. 64 66-67 (2019).
[2] G. K. Kumar, et al., Jour. Phys. G: Nucl. Part. Phys. 35 095104 (2008).
[3] A. R. Poletti, et al., Physical Review C 10 2329-2339 (1974).
[4] M. Ogawa and H. Taketani, Nucl. Phys. A 194 259-291 (1972).
[5] D.C.Radford, A.R.Poletti, J. Phys. G 5, 409 (1979).
[6] A.A. Avaa, et al., Physical Review C (in preparation)

Speaker: Abraham Avaa (iThemba/Wits)

17:00 → 19:00 Function: Braai

Wednesday, 18 May

10:00 → 11:05 Environmental Applications

Convener: Daniel BONGUE (Centre for Atomic Molecular Physics and Quantum Optics (CEPAMOQ) - Faculty of Science - University of Douala - Cameroon)

10:00 Environmental Radioactivity Monitoring and Radiological Impact Assessment of Agbara Industrial Area, Ogun State, Nigeria

Naturally occurring radionuclides of terrestrial origin exists in every component of the earth. Making humankind to be continuously exposed to ionizing radiation, which is dangerous to human health. Monitoring of environmental radioactivity is very crucial to minimizing exposure above the threshold limit. Consequently, the background radioactivity due to 232Th, 238U, and 40K for some locations in Agbara industrial area of Ogun State was determined using RS230 Gamma Spectrometer (a portable NaI [Tl] detector). The mean activity concentration of the primordial radionuclides ranges between below detectable limit (in Mentos area) and 472.14 Bqkg-1 (Access Bank area) with an overall average value of 177.87 Bqkg-1. The in-situ measured dose rate (DR) ranges between 12. 18 nGyh-1 (Access Bank area) and 97.95 nGyh-1 (Market area), with an average value of 47.22 nGyh-1. The measured and estimated absorbed dose rates were within the safe limit of 57 nGyh-1 provided by UNSCEAR. The mean values of all the estimated radiological parameters were within the recommended threshold values. It could be concluded that the risk of exposure higher level of ionizing radiation is low for all the area in Agbara industrial area of Ogun State, but there is possibility of cancer risk for someone that has stayed in the area for 70 years and above.

Keywords: Environmental Assessment Impact, Radioactivity, Radiological Parameters, Agbara Industrial Estate.

Speaker: Dr Mojisola Usikalu (Covenant University)

10:45 SURVEY OF RADIATION LEVELS AT ITHEMBA LABS USING A MOBILE RADIATION DETECTION UNIT EQUIPPED WITH A LaBr3:Ce DETECTOR

A mobile radiation detection unit (MRDU) was developed to measure the radiation levels outside the iThemba LABS buildings, within the borders of the facility. The main attraction of this mobile unit is the fact that it is equipped with a LaBr3:Ce detector. This detector is superior to more conventional detectors (such as NaI:Tl) because of typically better spectral resolution, a high photon yield, and good detection efficiency [1, 2, 3]. It is known that the LaBr3:Ce detector has various sources of intrinsic activity of which the main cause is the presence of the radioactive 138La-isotope in the scintillation crystal [4]. One of the decay modes of 138La produces a gamma photon at 1435.8 keV which overlays with the 40K energy peak at 1460.8 keV when the detector resolution is taken into account. To quantify 40K activity this internal interference needs to be corrected. Additional to this, the influence of the radiation-source geometry also needs to be considered, especially during terrestrial surveys. This has a direct influence on detector efficiency which is a fundamental parameter for the accurate calculation of activity concentrations for the various radionuclides present in natural environments. Using the mobile radiation detection unit an assessment of radiation at the outside areas of the iThemba LABS facility was done. It was possible to elucidate the naturally occurring nuclides as well as 22Na from the gamma-ray spectra obtained. Due to the constant change in this geometry at the storage containers the 22Na, in particular, could only be estimated. Considering background radiation as well as the intrinsic radiation from the detector due to the presence of radioactive 138La, the activities of the nuclides were estimated to be 49.1 Bq/kg for 40K, 3.78 Bq/kg for 238U, 12.8 Bq/kg for 232Th and 72.5 kBq for 22Na. The effective dose rate of the NORM-nuclides was calculated as 0.0043 mSv/y.

Speaker: Ferdie van Niekerk (Tshwane University of Technology)

11:05 → 11:30 Coffee Break

11:30 → 13:05 Environmental Applications

Convener: Gharib Mohamed (The State University of Zanzibar)

11:30 EVALUATION OF RADIOLOGICAL HAZARDS DUE TO NATURAL RADIOACTIVITY IN SOIL SAMPLES COLLECTED IN AND AROUND SOME GOLD MINING AREAS OF THE MAYO-KEBBI REGION IN CHAD WITH STATISTICAL ANALYSES.

In this work, a HPGe detector in a low-background setup was used to determine the activity concentrations of 238U, 232Th and 40K in soil samples collected in and around some gold mining areas of the Mayo-Kebbi region in Chad. Subsequently, the radiological risks due to these natural radionuclides were also assessed. The range of activity concentrations of 238U, 232Th and 40K varied respectively from 1.42 to 430.88 Bq/kg, 1.19 to 56.61 Bq/kg and 27.38 to 840.51 Bq/kg with respective average values of 29.67 Bq/kg, 11.98 Bq/kg and 234.43 Bq/kg. The highest value of 238U, 232Th and 40K concentrations were found in soil sample collected at gold mining area of Zabili. Correlation studies between 238U versus 232Th, 40K versus 238U, and 40K versus 232Th were performed. The results showed a good correlation between the pairs (238U, 232Th) however a weak correlation was observed between the pairs (238U, 40K) and (232Th, 40K). In order to investigate the statistical variation of the data and its implications on environmental exposure, the hierarchical binary cluster tree was implemented. The mean annual effective dose of the soil samples collected in the studied area was found to be 0.18 mSv/y. The calculated mean values of the external hazard index (Hex) and the internal hazard index (Hin) of the study area were 0.26, 0.26, respectively. These values are lower than unity. Therefore, mining activities in Mayo-kebbi region do not present any radiological hazard to the general public.

Speakers: Daniel BONGUE (Centre for Atomic Molecular Physics and Quantum Optics (CEPAMOQ) - Faculty of Science - University of Douala - Cameroon) , Mr Samafou Penabei

12:15 Radioactivity assessment of radium and radon concentrations in water sources at and near selected former uranium mines in the West-Rand area of Johannesburg

The present work aimed at establishing the extent and distribution of the activity concentration levels of 238U daughter-nuclides; 226Ra and 222Rn in the
West Rand-area of Johannesburg. The main motive was to ascertain whether
the exposure of the nearby residents to ionising radiation due to former mining
activities was within the maximum acceptable limit of 1.0 mSv/y for the public. Measurements include the use of Alpha Spectroscopy system (Canberra)
with Passivated Implanted Planar Silicon (PIPS) and Solid-state Alpha Detectors for Radon measurements (RAD-7) detectors to identify radionuclides,
quantify and analyze isotopes of interest.
A seasonal collection of a total 32 water samples from the mining areas
was carried out and analysed for 226Ra and 222Rn. The results of radium
(
226Ra) concentration in water samples obtained by using alpha spectrometry
ranged from (1.58±2.74 to 164.42±18.47) mBq/l, (11.23±3.89 to 136.01±15.4)
mBq/l, (-3.38±-2.39 to 156.15±18.14) mBq/l, and (4.25±1.23 to 108±8) for
June 2019, September 2019, December 2019 and March 2020 water samples,
respectively. The radium values were lower than the suggested maximum contamination levels by US-EPA 555 mBq/L.
The results shows that the range of radon (222Rn) concentration values
vary from (37.1±74.1 to 269±79.2) mBq/l, (57.2±73.9to 190±94.9) mBq/l,
(76.6±63.2 to 211±146) mBq/l, and (56.3±71.1 to 289±272) mBq/l for June
2019, September 2019, December 2019 and March 2020, respectively. The obtained 222Rn concentration results in drinking water samples in the current
study are low than the approved maximum contamination level (MCL) 11.1
Bq/l as approved by US-EPA.
The observed radon annual ingestion dose from the current study were
lower than the European Commission and the World Health Organization proiii
posed concentration of 222Rn in drinking water of 100 Bq/l [1]. The results of
this study indicates that the total annual effective doses from possible intake
of 226Ra and 222Rn radionuclides in sampled water in West-Rand area were
found below the World Health Organisation (WHO) recommended limit of 0.1
mSv/y as well as the average radiation dose of 0.29 mSv/y received per head
worldwide due to ingestion of natural radionuclides assessed by UNSCEAR 2002

Speaker: Ayabulela Tsewu (Student)

12:35 Implementation of the k0-based Neutron Activation Analysis (NAA) methodology and k0-IAEA program at the Centre for Energy Research and Training (CERT), Zaria, Nigeria

Implementation of the k0-standardization method of Neutron Activation Analysis (NAA) technique and k0-IAEA program with the Nigeria Research Reactor-1 (NIRR-1) laboratories’ irradiation and counting facilities was carried out as part of a series of projects aimed at achieving one of the goals of the Strategic Utilization Plan for NIRR-1. Adoption of the k0-standardization method of NAA technique and the k0-IAEA gamma-ray spectrum analysis software was due to versatility in meeting the criteria of experimental simplicity, analytical accuracy, and flexibility (with respect to activation and counting conditions). The application of this methodology involved the installation of the k0-IAEA software, editing of its permanent database, calibration of HPGe detectors, and characterization of the irradiation facility prior to its use for routine analysis. IAEA (Soil-7) certified reference material was used to evaluate the validity of this method in NIRR-1 NAA laboratories by analyzing the elemental concentrations with respect to the certified values. In general, good agreement was obtained between the results of this work and values in the certificate of the reference material, thus validating the k0 standardization method of NAA using the k0-IAEA program and confirming its suitability for environmental studies in NIRR-1 laboratories.

Keywords: Neutron activation analysis, k0-standardization, k0-IAEA program, irradiation facility, HPGe detectors.

Speaker: Dr Michael Adeleye (Bingham University, Nigeria)

13:05 → 14:00 Lunch

14:00 → 14:30 Environmental Applications

14:00 Gamma-ray spectroscopy and its associated radiological risk of beach sand and soil samples from Zanzibar, United Republic of Tanzania

Everyone on the planet is exposed to some background radiation. Human exposure to ionising radiation is one of the scientific subjects that attract public attention, since radiation of natural origin is responsible for most of the total radiation exposure of the human exposure.
This study presents the results of Gamma-ray spectroscopy and its associated radiological risk of beach sand and soil samples from Zanzibar, United Republic of Tanzania. The activity concentration of natural radionuclides (40K, and 232Th and 238U decay products) in beach sand and soil samples were measured using a combination of in-situ and ex-situ gamma-ray spectroscopy. The in-situ gamma-ray survey was conducted using the Multi Element Sediment Detector for Underwater Sediment Activity (MEDUSA) detector. The detector was mounted on the front of a 4×4 vehicle, 60 cm off the ground. Activity concentrations of the primordial radionuclides were extracted from the MEDUSA spectra using the Full Spectrum Analysis (FSA) procedure. The collected beach sands and soil samples from the beaches and the land mapped using the MEDUSA detector were analysed using a Hyper Purity Germanium (HPGe) detector.
The activity concentrations of 40K, 238U and 232Th in beach sand are much lower than in soil samples, with one major exception at Kukuu. Two beach sand samples from Kukuu beach were found to have enhanced radioactivity levels due to the presence of heavy minerals.
The spatial distributions maps for 40K, 238U and 232Th show large variation in soil samples for two relatively small islands. These strong variations are unexpected, that could have implications for agriculture.
The outdoor gamma dose rates obtained in beach sand and soil samples ranged from 3 to 2156 nGy h-1 and 50 to 294 nGy h-1, respectively. The highest absorbed dose rates in soil samples and beach sand are respectively 5 and 38 times higher than the average world level of 57 nGyh-1 for terrestrial doses. Apart from the Kukuu black sand samples that contain the high 238U and 232Th levels, the beach sands and soil in this study do not pose any radiological threat to the public using beaches for various activities.

Speaker: Gharib Mohamed (The State University of Zanzibar)

14:30 → 15:30 Discussion Session: Environmental Measurements

Conveners: Daniel BONGUE (Centre for Atomic Molecular Physics and Quantum Optics (CEPAMOQ) - Faculty of Science - University of Douala - Cameroon) , Stephan Woodborne

15:30 → 16:00 Tea Break

16:00 → 17:00 Professional Development

Thursday, 19 May

10:00 → 11:05 Nuclear Structure Studies

Convener: Lindsay Donaldson (iThemba Laboratory for Accelerator Based Sciences)

10:00 Lifetime measurements on A∼100 nuclei using LaBr3(Ce) arrays.

The region of the nuclear chart around neutron-rich A~100 nuclei is one where prolate and oblate nuclear shapes are predicted to be in close competition. An indirect measurement of the shape of the nucleus can be obtained from measuring level lifetimes which relate, via transition rates, to beta_2 deformation. In order to make measurements of level lifetimes in the sub nanosecond range an array of 36 LaBr3(Ce) detectors has been constructed for use at the FAIR facility in Darmstadt, Germany. This presentation will give an overview of the array and examples of its use in commissioning experiments at the RIKEN Nishina Center in Japan and the Argonne National Laboratory in the USA.

Speaker: Prof. Alison Bruce (University of Brighton)

10:45 Overview on the African LaBr Array at iThemba LABS

The African LaBr Array (ALBA) consists of 21 large volume LaBr3:Ce. The characteristics of these crystals, such as the good energy resolution and the high efficiency, make this array very useful for the detection of high-energy gamma rays. The ALBA project foresees the use of the gamma spectrometer in stand-alone mode and coupled to the K600 spectrometer or to silicon-detector arrays for the particle identification. A Digital acquisition system based on XIA PIXIE 16 cards (12 bit 500Mz digitization) will be used. The 21 detectors of ALBA arrived in 2021 and the S-line support frame is now being completed. An overview of the project will be given underling the physics program that is envisage for the upcoming future.

Speaker: Luna Pellegri (University of the Witwatersrand and iThemba LABS)

11:05 → 11:30 Coffee Break

11:30 → 13:00 Nuclear Structure Studies

Convener: Dr Zina Ndabeni (University of Cape Town)

11:30 Strength of the scissors resonance in 151Sm

The number of stable isotopes of samarium (Sm), makes this isotopic chain interesting to study at stable ion beam facilities. The scissors resonance (SR) of 151Sm was studied with the aim of understanding the evolution of the SR along the Sm isotopic chain. Change in deformation of a nucleus as it transitions from prolate through spherical to oblate, leads to changes in statistical properties particularly the nuclear level density (NLD) and γ-strength function (γSF). The evolution of resonances observed in the γSF, such as the SR which is sensitive to changes in deformation across the isotopic chain, was studied in this work. The experiment was performed at the Oslo Cyclotron laboratory where a 152Sm self-supporting target was bombarded with a 13.5 MeV deuteron beam. The reaction 152Sm (d,tγ)151Sm populated the nucleus of interest. An array of NaI(Tl) detectors, CACTUS [1], detected γ-rays and the silicon particle telescope array, SiRi [2], was used to detect charged particles in coincidence. The NLD and γSF were extracted from the particle-γ coincidences below the neutron separation energy, Sn, using the Oslo Method [3].
These results are used to place the SR in 151Sm and its magnetic dipole strength B(M1) value into the context of previously measured samarium isotopes[4, 5, 6]. I will present the results for 151Sm, which depicts a near complete picture of the evolution of the strength of the SR [B(M1)] for the stable Sm isotopic chain.

Speaker: Ms Sebenzile Magagula (SSC Laboratory, iThemba labs, Somerset west, 7129, South Africa)

11:50 Photon strength functions from (p, γ) reactions

In the 1970s and 80s (p, γ) reactions were successfully utilized to measure the photon strength function (PSF) using the Average Resonance Capture Method [1] and this work seeks to explore these reactions to measure the PSF using the ratio and X2 method [2]. The 50Cr(p, γ)51Mn capture reaction has been used to study primary γ-ray transitions from the entry states between the proton and neutron separation energies to discrete states of known spins and parities. For a proof-of-principle experiment, the Tandetron accelerator at iThemba LABS was used to deliver proton beams of 2.5 to 3 MeV and 3.675 to 4.498 MeV in intervals of 20-25 keV with beam currents of up to 5 𝜇A. The primary γ-rays emitted from the reaction were detected using one segmented Clover detector placed at 90° to the beam direction. A total of 64 gamma-ray spectra were collected with 26 and 38 of these spectra collected for 2.5 to 3 MeV and 3.675 to 4.498 MeV beam energies respectively. The level scheme of the 51Mn compound nucleus was built with several new transitions and states being identified. The average intensities of the primary γ-rays decaying to discrete states of known spin and parity were extracted. The PSF of 51Mn will be extracted using the ratio and X2 method [2]. In this talk, I will present the analysis and preliminary results on the extraction of the PSF of 51Mn populated using 50Cr(p, γ) reaction.

Speaker: Mr Adivhaho Netshiya (iThemba LABS and WITS)

12:10 Ion source development for the LERIB test facility

Ion-source development for the LERIB test facility

Skye Segal1, J. Abrahams1, H. Anderson1, S. Baard1, R. Bark1, H. Barnard1, J. Conradie1, B. Cornelius1, A. Crombie1, J. de Villiers1, W. Duckitt1, C. Ellis1, D. Fourie1 and P. Van Schalkwyk1

1iThemba LABS, South Africa

At the off-line test facility of the Low-Energy Radioactive-Ion Beam, or LERIB [1] project, at iThemba LABS, two ion-sources are being developed: a surface ion source, and a Forced Electron Beam Induced Arc Discharge, or FEBIAD, plasma ion-source [2].
The hot-cavity type surface ionization source has already undergone some development at the LERIB off-line test facility. The production of ions from group 1 was accomplished with the creation of stable beams of 39K+, 41K+ and 23Na+, and beam currents were measured in the µA range. This source is a good choice as a pilot beam for similar mass beams that could eventually be used for RIB experiments - stable and bright beams can be created, and they can be switched on or off quickly by limiting heating current through the tantalum oven.
The LERIB FEBIAD is in its initial stages of development. The FEBIAD will be essential for the production of RIBs, as a wide variety of elements can be ionized with it through the process of electron-impact ionization. The FEBIAD under consideration will include the use of magnetic fields for the confinement of the electron beam. Magnetic fields produced by solenoids have been shown to improve the ionization in plasma ion sources [3]. Electromagnetic solenoid fields as well as arrays of permanent magnets will be studied for use in the LERIB FEBIAD.

[1] J. Conradie, et al., Progress with a New Radioisotope Production Facility and Construction of Radioactive Beam Facility at iThemba LABS, (2016).
[2] T. Stora, Radioactive Ion Sources, CERN Yellow Report CERN-2013-007 pp.331-349 (2014).
[3] J. Ballof, et al., A cold electron-impact ion source driven by a photo-cathode, (2022).

Speaker: Dr Skye Segal (iThemba LABS)

13:00 → 14:00 Lunch

14:00 → 15:00 Discussion Session: Nuclear Structure

Conveners: Jacobus Diener (Botswana International University of Science and Technology) , Luna Pellegri (University of the Witwatersrand and iThemba LABS)

15:00 → 15:30 Tea Break

Friday, 20 May

10:00 → 10:45 Collaborations and Networking

Convener: Alison Bruce (University of Brighton)

10:00 The Role of Inter-Africa UK Collaboration in Improving Nuclear Instrumentation for Research and Development in Africa

In the current world of science and technology, the contribution of nuclear science, technology and techniques cannot be overestimated. Humankind have benefited from many aspects of nuclear science and technology especially in areas such as power production, health services, agricultural developments and security. Moreover, nuclear techniques have continued to be beneficial for analysing food as well as environmental samples hence promoting good quality of life for everyone. Such benefits are the outcomes of continuous research efforts and knowledge expansion in nuclear science. That is to say, continuous research and development (R&D) activities is the key to the future success. Yet, the R&D activities require reliable expertise and instrumentation, which are vital aspects for safe and effective use of several nuclear techniques and technology. Nevertheless, most developing countries are far behind the developed countries in terms the aforementioned aspects. This causes not only difficulties in conducting cutting edge nuclear researches in the developing countries but also failure to take full advantage of the available nuclear technology, which could hugely boost the economies of these countries. In order to ease the situation, research collaborations between the less developed, developing and developed countries have always been suggested to take advantage of the available nuclear instruments. Thus, nuclear instrumentation and expertise make an important point of focus for collaborations between African countries and the United Kingdom (UK). This talk will highlight the importance of the inter-Africa and United Kingdom (UK) collaborations in the development of nuclear instrumentation and nuclear technology in Africa taking Tanzania as a case study.

Speaker: Innocent Jimmy Lugendo (University of Dar es Salaam)

10:45 → 11:15 Function: Tour: SAIF Facility

11:15 → 11:45 Coffee Break

11:45 → 12:30 Collaborations and Networking

Conveners: Alison Bruce (University of Brighton) , Pete Jones (iThemba LABS)

12:30 → 13:00 Closing and Final Remarks

13:00 → 14:00 Lunch