BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Recent Research Activities and Perspectives for Collaboration DTSTART;VALUE=DATE-TIME:20260519T104000Z DTEND;VALUE=DATE-TIME:20260519T110000Z DTSTAMP;VALUE=DATE-TIME:20260624T075619Z UID:indico-contribution-646-3852@indico.tlabs.ac.za DESCRIPTION:Speakers: Armand Bahini (University of Caen Normandie / Labora toire de Physique Corpusculaire Caen (LPC Caen))\nA brief overview will be given of ongoing research directions at Laboratoire de Physique Corpuscul aire de Caen related to environmental radiation measurements and the devel opment of innovative portable low-cost detector systems for environmental monitoring applications. Possible avenues for future collaboration between the South African and French teams in this field will also be discussed.\ n\nhttps://indico.tlabs.ac.za/event/139/contributions/3852/ LOCATION:NRF-iThemba LABS\, Old Faure Road\, Cape Town Auditorium URL:https://indico.tlabs.ac.za/event/139/contributions/3852/ END:VEVENT BEGIN:VEVENT SUMMARY:Measurement of Azimuthal Bremsstrahlung Photon Emission from a 28- GHz ECR Ion Source Using NaI(Tl) Detectors DTSTART;VALUE=DATE-TIME:20260519T102000Z DTEND;VALUE=DATE-TIME:20260519T104000Z DTSTAMP;VALUE=DATE-TIME:20260624T075619Z UID:indico-contribution-646-3822@indico.tlabs.ac.za DESCRIPTION:Speakers: Mwingereza John Kumwenda (University of Dar es Salaa m)\nThe emission of high-energy bremsstrahlung photons beyond the expected critical energy during electron cyclotron resonance (ECR) heating has att racted significant attention\, and its underlying mechanism remains not fu lly understood. In this study\, we measured the azimuthal angular distribu tion of bremsstrahlung photons produced in a 28 GHz ECR ion source at the Busan Center of the Korea Basic Science Institute (KBSI). Three round-type NaI(Tl) scintillation detectors were used to simultaneously measure brems strahlung photons emitted radially from the plasma chamber. An additional NaI(Tl) detector was positioned downstream of the ECR ion source to monito r the overall photon intensity. The ion source was operated at an RF power of 1 kW to extract an 16O ion beam\, with dominant charge states of O³ ⁺ and O⁴⁺. Bremsstrahlung photon energy spectra were recorded at nin e azimuthal angles on the extraction side of the ion source. To evaluate p ossible systematic uncertainties arising from differences among the three detectors\, measurements were repeated by alternating the detector positio ns. Geant4 Monte Carlo simulations were performed to account for geometric al acceptance and energy-dependent detection efficiency caused by non-unif ormities in the material budget. The true bremsstrahlung spectra were then reconstructed using an inverse-matrix unfolding method. The extracted end -point energies of the bremsstrahlung spectra were (2.040 ± 0.045) MeV at 150°\, (1.650 ± 0.040) MeV at 330°\, and (1.610 ± 0.040) MeV at 330° for detectors D1\, D2\, and D3\, respectively. These values exceed the ma ximum electron kinetic energy of approximately 1.330 MeV expected from sta ndard ECRIS operating parameters. The higher end-point energy observed nea r 150° appears to correlate with the structural configuration of the ion source and the the shape of the ECR plasma. However\, the secondary maximu m near 330°\, located roughly 180° opposite to 150∘ which is among the maximum angles\, cannot be explained solely by the shape of the ECR plasm a. We interpret these observations as evidence of unconfined high-energy e lectrons reaching the chamber wall and producing bremsstrahlung radiation. These escaping electrons likely arise from imperfect magnetic confinement within the ECR plasma. The results provide new insight into the mechanism s of high-energy bremsstrahlung production in ECR ion sources and suggest that improved magnetic confinement design could reduce electron losses and associated high-energy photon emission.\n\nhttps://indico.tlabs.ac.za/eve nt/139/contributions/3822/ LOCATION:NRF-iThemba LABS\, Old Faure Road\, Cape Town Auditorium URL:https://indico.tlabs.ac.za/event/139/contributions/3822/ END:VEVENT BEGIN:VEVENT SUMMARY:Investigating radiological risk due to solid-phase ‘black powder ’ from the Secunda Gas Pipeline DTSTART;VALUE=DATE-TIME:20260519T100000Z DTEND;VALUE=DATE-TIME:20260519T102000Z DTSTAMP;VALUE=DATE-TIME:20260624T075619Z UID:indico-contribution-646-3813@indico.tlabs.ac.za DESCRIPTION:Speakers: Tsholofelo Mokgele (North-West University )\nThe ext raction and transport of natural gas leads to the accumulation of black po wder\, a hazardous byproduct composed of corrosion species\, microorganism s and Naturally Occurring Radioactive Materials (NORM) within gas pipeline s. These NORM contaminants tend to concentrate within dust filters and dur ing periodic 'pigging' operations\, posing a potential radiological threat to workers and the environment. The study evaluated the radiological asse ssment of black powder collected at the Secunda gas pipeline by determinin g the activity concentrations of naturally occurring radionuclides 226Ra\, 232Th and 40K using gamma spectrometry. Results show that the average act ivity concentrations for black powder obtained from pigging operations wer e 2.53 ± 0.18 (range: 1.87 - 2.94)\, 4.23 ± 0.32 (range: 2.78 - 5.00) an d 27.17 ± 1.75 (range: 23.59 - 29.76) Bq/kg for 226Ra\, 232Th and 40K res pectively. Similarly\, the average activity concentrations for black powde r obtained from dust filters during normal operations resulted in 1.82 ± 0.21 (range: 1.34 - 2.24)\, 1.67 ± 0.26 (range: 1.27 - 2.21)\, 25.98 ± 1 .73 (range: 18.36 - 2.71) Bq/kg for 226Ra\, 232Th and 40K respectively. Ra diological hazard indices were also determined by calculating the Raeq\, D \, Hex\, Hin\, AEDE and ELCR. Average values for these indices for black p owder samples from pigging operations were 10.68 Bq/kg\, 4.86 nGy/h\, 0.03 \,0.04\, 5.96 × 10-3 mSv/yr and 2.0 × 10-5 respectively. For black powde r samples from dust filters\, the corresponding average values were 5.13 B q/kg\, 2.47 nGy/h\, 0.01\, 0.02\, 3.03× 10-3 mSv/yr and 1.06 × 10-5\, re spectively. All calculated radiological hazard indices were significantly below the recommended regulatory safety limits\, indicating negligible rad iological risks to maintenance workers during pigging and filter replaceme nt operations.\n\nhttps://indico.tlabs.ac.za/event/139/contributions/3813/ LOCATION:NRF-iThemba LABS\, Old Faure Road\, Cape Town Auditorium URL:https://indico.tlabs.ac.za/event/139/contributions/3813/ END:VEVENT BEGIN:VEVENT SUMMARY:Revisiting Radiocesium Retention in Japanese Cedar: Implications f or Post-Accident Forest Recovery DTSTART;VALUE=DATE-TIME:20260519T093000Z DTEND;VALUE=DATE-TIME:20260519T100000Z DTSTAMP;VALUE=DATE-TIME:20260624T075619Z UID:indico-contribution-646-3837@indico.tlabs.ac.za DESCRIPTION:Speakers: Muyiwa Orosun (Institute of Environmental Radioactiv ity\, Fukushima University)\nThe long-term management of contaminated fore st landscapes depends not only on declining environmental inventories of r adiocesium (137Cs)\, but also on how this radionuclide is retained within commercially important tree species. Japanese cedar (Cryptomeria japonica) \, which underpins much of Japan’s plantation forestry\, exhibits an unu sual internal distribution of 137Cs within wood (stem)\, marked by prefere ntial accumulation in heartwood rather than sapwood. This pattern challeng es conventional assumptions about radionuclide behavior in woody tissues a nd raises questions about the processes controlling internal redistributio n and retention. This study synthesizes current knowledge and ongoing work s on radial radiocesium dynamics in Japanese cedar\, focusing on anatomica l\, physiological\, and environmental factors that may drive these observa tions. Key uncertainties are identified\, and directions for future resear ch are outlined to improve predictive capability and inform risk-based dec isions on the utilization of forest timber in post-accident environments. \n\nKeywords: Japanese cedar\, Radiocesium\, Forest ecosystems\, Fukushima .\n\nhttps://indico.tlabs.ac.za/event/139/contributions/3837/ LOCATION:NRF-iThemba LABS\, Old Faure Road\, Cape Town Auditorium URL:https://indico.tlabs.ac.za/event/139/contributions/3837/ END:VEVENT BEGIN:VEVENT SUMMARY:An Integrated Baseline Environmental Radioactivity Assessment Acro ss Various Exposure Pathways DTSTART;VALUE=DATE-TIME:20260519T082000Z DTEND;VALUE=DATE-TIME:20260519T084000Z DTSTAMP;VALUE=DATE-TIME:20260624T075619Z UID:indico-contribution-646-3830@indico.tlabs.ac.za DESCRIPTION:Speakers: Thato Molokwe (Centre for Nuclear Safety and Securit y)\nMonitoring natural radionuclides in the environment is important for e stablishing baseline radioactivity levels that support the evaluation of p ublic exposure. The study presents baseline environmental radioactivity le vels measured in collected soil\, external gamma\, water and indoor radon samples to assess resultant public doses through external\, inhalation and ingestion exposure pathways. \n\nThe soil media comprised six (6) beach s and samples\, seven (7) sediments\, and twenty-two (22) surface soils. Wat er samples included twelve (12) surface water\, five (5) seawater\, and si xteen (16) groundwater samples\, which were analysed for natural radionucl ides originating from the Uranium-238\, Uranium-235 and Thorium-232 decay series. External gamma radiation measurements were conducted at fifty-thre e (53) locations\, and indoor radon concentrations were measured in fiftee n (15) dwellings. The water and soil samples were analysed using calibrate d gamma spectrometry and alpha spectrometry. External gamma radiation was measured in situ using a calibrated portable gamma survey meter (RS-230) t o determine ambient dose rates. Passive solid-state nuclear track detector s were deployed in dwellings for a period of three (3) months to measure i ndoor radon (Radon-222) concentrations.\n \nThe radioactivity levels measu red in soil samples were found to be significantly lower than the reported worldwide average values of 420 Bq/kg for Potassium-40\, 32 Bq/kg for Rad ium-226\, and 45 Bq/kg for Thorium-232. The calculated radiological hazard indices\, including radium equivalent activity and external hazard index\ , were also below internationally recommended safety limits. Similarly\, r adioactivity levels in water samples were below the World Health Organisat ion’s (WHO) recommended drinking water reference levels\, corresponding to an annual committed effective dose of less than 0.1 mSv/year. The measu red external gamma dose in the study area due to natural background radiat ion was below the reference level of 1 mSv/year\, which is the public dose limit for planned exposure situations. Indoor radon concentrations were g enerally below the 100 Bq/m³ reference level recommended by the World Hea lth Organisation\, except for one measurement (117 Bq/m³)\, which was non etheless below the 300 Bq/m³ action level recommended by the Internationa l Atomic Energy Agency (IAEA). Further investigations indicated that the e levated level was unlikely to be attributed to underlying geology but may instead be attributed to factors such as building characteristics or venti lation.\n\nThe results of this study provide integrated baseline data of e nvironmental radioactivity levels\, which are relevant for environmental m onitoring and assessment of public exposure. These findings support radiat ion protection and safety initiatives.\n\nhttps://indico.tlabs.ac.za/event /139/contributions/3830/ LOCATION:NRF-iThemba LABS\, Old Faure Road\, Cape Town Auditorium URL:https://indico.tlabs.ac.za/event/139/contributions/3830/ END:VEVENT BEGIN:VEVENT SUMMARY:Use of Environmental Measurements as a Tool to Understand Factors Influencing Radionuclides Concentrations DTSTART;VALUE=DATE-TIME:20260519T080000Z DTEND;VALUE=DATE-TIME:20260519T082000Z DTSTAMP;VALUE=DATE-TIME:20260624T075619Z UID:indico-contribution-646-3828@indico.tlabs.ac.za DESCRIPTION:Speakers: Paballo Marakalla (National Nuclear Regulator (CNSS) )\nRadon (Rn-222) is a radioactive gas that originates from uranium (U-238 ) and is ranked as a major source of natural ionising radiation and identi fied among the leading causes of lung cancer. It is therefore essential fo r its occurrence and concentration levels present in the environment to be well understood\, quantified and assessed. This study characterised indoo r radon levels regionally in the gold mining sites of Gauteng Province and coal mining sites in the Mpumalanga Province using the solid-state nuclea r track detectors\, which were deployed predominantly during summer and wi nter months. Moreover\, radon parent nuclides were determined in mine tail ing residues\, soils\, rocks and water to help in the understanding of the primary sources and controls of radon.\n \nThe study aimed to evaluate th e extent to which the local conditions such as the underlying lithology\, content of the parent radioisotopes in primary sources\, mining activities \, seasonal variations and building characteristics affect indoor radon. I t was found that the gold tailings residues and coal related operations ha ve no drastic effect on indoor radon concentrations measured in the dwelli ngs studied\, other than at a localized location where contamination resul ting from tailings materials was observed. The major contributing factors were the uranium content in geological formations and soil\, which depicte d a positive correlation with indoor radon concentrations at R² = 0.7827 for rocks and R² = 0.5302 for soil. The uranium content in the ground sur face was proven to be a good first indicator of indoor radon. Contribution s from water to indoor radon were found to be negligible. Variations in me teorological conditions with seasons\, ventilation rate of the house and t he rooms where measurements are conducted\, the age of the dwelling and ty pe of building materials were found as additional contributors and control s to indoor radon concentrations.\n\nhttps://indico.tlabs.ac.za/event/139/ contributions/3828/ LOCATION:NRF-iThemba LABS\, Old Faure Road\, Cape Town Auditorium URL:https://indico.tlabs.ac.za/event/139/contributions/3828/ END:VEVENT BEGIN:VEVENT SUMMARY:Why the Need for Environmental Measurement? DTSTART;VALUE=DATE-TIME:20260519T073000Z DTEND;VALUE=DATE-TIME:20260519T080000Z DTSTAMP;VALUE=DATE-TIME:20260624T075619Z UID:indico-contribution-646-3818@indico.tlabs.ac.za DESCRIPTION:Speakers: Munirat Bashir (Ibrahim Badamasi Babangida Universit y Lapai\, Nigeria)\nEnvironmental measurement is essential for evaluating environmental quality\, detecting contamination\, and protecting human hea lth. Increasing industrial\, agricultural\, and urban activities have led to the release of chemical and radiological pollutants into environmental systems. Accurate measurement of these parameters is therefore critical fo r monitoring environmental media such as air\, water\, and soil. This lect ure highlights the importance of environmental measurement in pollution de tection\, environmental risk assessment\, and regulatory compliance. Parti cular emphasis is placed on environmental radioactivity monitoring and the application of radiation detection techniques in assessing naturally occu rring and anthropogenic radionuclides. Strengthening environmental monitor ing capacity remains vital for effective environmental management and sust ainable development.\n\nhttps://indico.tlabs.ac.za/event/139/contributions /3818/ LOCATION:NRF-iThemba LABS\, Old Faure Road\, Cape Town Auditorium URL:https://indico.tlabs.ac.za/event/139/contributions/3818/ END:VEVENT END:VCALENDAR