BEGIN:VCALENDAR VERSION:2.0 PRODID:-//CERN//INDICO//EN BEGIN:VEVENT SUMMARY:Continuing Influence of Shell Effects in the Nuclear Quasi-Continu um DTSTART;VALUE=DATE-TIME:20190320T102000Z DTEND;VALUE=DATE-TIME:20190320T103500Z DTSTAMP;VALUE=DATE-TIME:20260715T222637Z UID:indico-contribution-271-1340@indico.tlabs.ac.za DESCRIPTION:Speakers: Cebo Ngwetsheni (University of the Western Cape)\nTh e nuclear dipole polarizability - a second order effect – governed by dy namics of giant dipole resonances was investigated. Along with the resulti ng effects of recently observed enhancement of photon strength functions at low energies for nuclide in A ≈ 50\, 90 mass region. Empirical drops observed in ground-state nuclear polarizabilities indicate deviations fro m the effect of giant dipole resonances and reveal the presence of shell e ffects in semi-magic nuclei with neutron magic numbers N = 50\, 82 and 126 . Similar drops of polarizability in the quasi-continuum of nuclei with\, or close to\, magic numbers N = 28\, 50 and 82\, reflect the continuing in fluence of shell closures up to the nucleon separation energy. These findi ngs strongly support recent large-scale shell-model calculations in the qu asi-continuum region describing the origin of the low-energy enhancement o f the radiative or photon strength function as induced paramagnetism\, and assert the Brink-Axel hypothesis as more universal than originally expect ed.\n\nhttps://indico.tlabs.ac.za/event/82/contributions/1340/ LOCATION:J Block Auditorium URL:https://indico.tlabs.ac.za/event/82/contributions/1340/ END:VEVENT BEGIN:VEVENT SUMMARY:Coulomb-excitation studies @ iThemba LABS DTSTART;VALUE=DATE-TIME:20190320T120000Z DTEND;VALUE=DATE-TIME:20190320T123000Z DTSTAMP;VALUE=DATE-TIME:20260715T222637Z UID:indico-contribution-271-1330@indico.tlabs.ac.za DESCRIPTION:Speakers: Nico Orce (University of the Western Cape)\nA new pi peline for Coulomb-excitation studies has been developed at iThemba LABS w ith the first particle-gamma coincidence measurements carried out during a two-month campaign in April-May 2016 using an XIA-based digital DAQ. We used the reorientation effect to determine the spectroscopic quadrupole mo ment of the first high-lying excitation in Tz=0 self-conjugate nuclei (20 Ne\, 32S\, 36Ar) - typically associated with clustering formation - and 40 Ar. These measurements present higher accuracy than previous work and\, su rprisingly\, for 20Ne\, 36Ar and 40Ar they represent the first measurement s done at safe bombarding energies\, well below the Coulomb barrier\, onto a heavy target. Our new results show a zig-zag pattern of nuclear shapes at the end of the sd shell and will be compared with state-of-the-art mean -field calculations. Five MSc degrees have been awarded from these data se ts.\n\nhttps://indico.tlabs.ac.za/event/82/contributions/1330/ LOCATION:J Block Auditorium URL:https://indico.tlabs.ac.za/event/82/contributions/1330/ END:VEVENT BEGIN:VEVENT SUMMARY:Hybrid potential analysis of alpha cluster structure above doubly- closed shell DTSTART;VALUE=DATE-TIME:20190320T130000Z DTEND;VALUE=DATE-TIME:20190320T133000Z DTSTAMP;VALUE=DATE-TIME:20260715T222637Z UID:indico-contribution-271-1356@indico.tlabs.ac.za DESCRIPTION:Speakers: TAOFIQ IBRAHIM (FEDERAL UNIVERSITY LOKOJA\, LOKOJA N IGERIA)\nPhenomenological interactions have been successful in the descrip tion of the alpha cluster structure of light nuclei. The interactions howe ver lack the required fundamental Nucleon-Nucleon character. This shortcom ing is addressed by exploiting the known surface localization of the clust er that is well described by microscopic interactions. The ground-state ba nd properties of 94Mo and 136Te were investigated using a Saxon-Woods type local interaction with parameters obtained from the microscopic double-fo lding potential. The hybrid interaction is supplemented with a short range interaction to correct the observed underbinding of the ground state resu lting from possibly the core-cluster overlap. The energy spectra\, reduced intra band transition rates\, decay width and the root- mean-square charg e radii were satisfactorily reproduced\n\nhttps://indico.tlabs.ac.za/event /82/contributions/1356/ LOCATION:J Block Auditorium URL:https://indico.tlabs.ac.za/event/82/contributions/1356/ END:VEVENT BEGIN:VEVENT SUMMARY:Overview on the African LaBr Array at iThemba LABS DTSTART;VALUE=DATE-TIME:20190320T073000Z DTEND;VALUE=DATE-TIME:20190320T080000Z DTSTAMP;VALUE=DATE-TIME:20260715T222637Z UID:indico-contribution-271-1332@indico.tlabs.ac.za DESCRIPTION:Speakers: Luna Pellegri (University of the Witwatersrand and i Themba LABS)\nThe African LaBr Array (ALBA) consists of 23 large volume La Br3:Ce. The characteristics of these crystals\, such as the good energy re solution and the high efficiency\, make this array very useful for the det ection of high-energy gamma rays. The ALBA project foresees the use of the gamma spectrometer in stand-alone mode and coupled to the K600 spectromet er or to silicon-detector arrays for the particle identification. A Digita l acquisition system based on XIA PIXIE 16 cards (12 bit 500Mz digitizatio n) is currently under test. \n\nThe first six detectors of ALBA arrived in 2018 and they were successfully used in an experiment to investigate the pygmy dipole resonance in deformed nuclei. An overview of the project will be given underling the physics program that is envisaged for the upcoming future.\n\nhttps://indico.tlabs.ac.za/event/82/contributions/1332/ LOCATION:J Block Auditorium URL:https://indico.tlabs.ac.za/event/82/contributions/1332/ END:VEVENT BEGIN:VEVENT SUMMARY:Wavelet signatures of K-splitting of the Isoscalar Giant Quadrupol e Resonance in deformed nuclei from high energy-resolution (p\,p$\\prime$) scattering off $^{146\,148\,150}$Nd DTSTART;VALUE=DATE-TIME:20190320T095000Z DTEND;VALUE=DATE-TIME:20190320T102000Z DTSTAMP;VALUE=DATE-TIME:20260715T222637Z UID:indico-contribution-271-1333@indico.tlabs.ac.za DESCRIPTION:Speakers: Chamunorwa Oscar Kureba (Botswana International Univ ersity of Science and Technology)\nThe phenomenon of fine structure of the Isoscalar Giant Quadrupole Resonance (ISGQR) has been studied with high e nergy-resolution proton inelastic scattering at iThemba LABS\, in the chai n of stable even-mass Nd isotopes covering the transition from spherical t o deformed ground states. A wavelet analysis of the background-subtracted spectra in the deformed $^{146\,148\,150}$Nd isotopes reveals characterist ic scales in correspondence with scales obtained from a Skyrme RPA calcula tion using the SVmas10 parameterization. A semblance analysis shows that t hese scales arise from the energy shift between the main fragments of the K = 0\, K = 1 and K = 2 components.\n\nhttps://indico.tlabs.ac.za/event/82 /contributions/1333/ LOCATION:J Block Auditorium URL:https://indico.tlabs.ac.za/event/82/contributions/1333/ END:VEVENT BEGIN:VEVENT SUMMARY:Plans for the new K600 focal plane detector DTSTART;VALUE=DATE-TIME:20190320T070000Z DTEND;VALUE=DATE-TIME:20190320T073000Z DTSTAMP;VALUE=DATE-TIME:20260715T222637Z UID:indico-contribution-271-1334@indico.tlabs.ac.za DESCRIPTION:Speakers: Retief Neveling (iThemba LABS)\nA new position sensi tive detector system for the focal plane of the K600 magnetic spectrometer is currently being developed. The existing focal plane detectors (FPDs) w ere designed to detect Z≤2 ions with kinetic energies 30 MeV/u or higher . A new low-pressure gas-filled tracker combined with a stopping scintilla tor detector is required to allow for the efficient detection of heavier p articles (Z>2) over a range of kinetic energies\, as well as light particl es (Z≤2) at lower kinetic energies (<30 MeV/u). The different physics c ases currently envisaged that require the low- pressure gas-filled detecto r will be reviewed\, and an overview of the design of the new FPD will be presented.\n\nhttps://indico.tlabs.ac.za/event/82/contributions/1334/ LOCATION:J Block Auditorium URL:https://indico.tlabs.ac.za/event/82/contributions/1334/ END:VEVENT BEGIN:VEVENT SUMMARY:Neutron-rich nuclei in the vicinity of 208Pb DTSTART;VALUE=DATE-TIME:20190320T080000Z DTEND;VALUE=DATE-TIME:20190320T083000Z DTSTAMP;VALUE=DATE-TIME:20260715T222637Z UID:indico-contribution-271-1337@indico.tlabs.ac.za DESCRIPTION:Speakers: Zsolt Podolyak (University of Surrey)\nInformation g ained on neutron-rich N~126 nuclei is essential for the understanding of n uclear structure in heavy nuclei. Studies around doubly magic systems allo w direct tests of the purity of shell model wave functions. In the case of the beta decay of N~126 nuclei there is strong competition between allowe d and first-forbidden transitions. This is the mass region where first-for bidden transitions can be dominant. The prediction of the FF component of the beta decay also requires good understanding of the wave-functions of i ndividual states. From a longer-term perspective\, experiments in this reg ion pave the way toward the proposed nuclear-astrophysical r-process waiti ng point nuclei along the N = 126 shell closure. \nRecently several experi ments were performed at ISOLDE with the aim to study neutron-rich nuclei a round 208Pb. Both beta decay and Coulomb excitation were used. In addition \, the coupling of the iThemba LABS K600 spectrometer with a Ge array will allow the study of nuclei in this mass region in particle transfer experi ments.\nThe presentation will report on recent results and their relevance on the structure of neutron-rich nuclei around 208Pb\, and it will explor e future opportunities.\n\nhttps://indico.tlabs.ac.za/event/82/contributio ns/1337/ LOCATION:J Block Auditorium URL:https://indico.tlabs.ac.za/event/82/contributions/1337/ END:VEVENT BEGIN:VEVENT SUMMARY:Electric Monopole Transitions (E0) in the study of 70Ge DTSTART;VALUE=DATE-TIME:20190320T083000Z DTEND;VALUE=DATE-TIME:20190320T084500Z DTSTAMP;VALUE=DATE-TIME:20260715T222637Z UID:indico-contribution-271-1338@indico.tlabs.ac.za DESCRIPTION:Speakers: Abraham Avaa (iThemba/Wits)\nMonopole transition stu dies has been of theoretical and experimental interest for over 50 years n ow. Since gamma decay is forbidden between two 0+ states\, the study of nu clear structure through the usual technique of gamma measurement cannot be useful in such a case. Hence\, the decay mode of spin zero state is most probable by electron emission. Depending on the probable transition energi es\, this can be achieved through either internal conversion or by interna l pair formation. Therefore\, measurement of electrons is crucial for E0 s tudies. \nIn order to implement E0 studies at iThemba labs\, an electron s pectrometer has been refurbished and characterised using calibration sourc es of internal conversion electrons (ICE): 133Ba and 207Bi. The results of the spectrometer characteristics are described. The spectrometer coupled with an array of fast timing detectors and Low energy photon spectrometer (LEPS) was successfully implemented for in-beam experiment. \nPreliminary result will be presented for the measured conversion coefficient and mono pole strength parameter in 72Ge and 72Se determined from electron-gamma co incident experiments from 70Ge(α\,α') reaction.\n\nhttps://indico.tlabs. ac.za/event/82/contributions/1338/ LOCATION:J Block Auditorium URL:https://indico.tlabs.ac.za/event/82/contributions/1338/ END:VEVENT BEGIN:VEVENT SUMMARY:Source Head Fluence Modulation in Cobalt-60 Teletherapy: A dosimet ric and Monte Carlo study DTSTART;VALUE=DATE-TIME:20190320T123000Z DTEND;VALUE=DATE-TIME:20190320T130000Z DTSTAMP;VALUE=DATE-TIME:20260715T222637Z UID:indico-contribution-271-1341@indico.tlabs.ac.za DESCRIPTION:Speakers: Nhlakanipho Mdziniso (Department of Physics\, Univer sity of Eswatini\, Faculty of Science and Engineering)\n**Background and P urpose**: Innovations in external beam radiotherapy have been limited to l inear accelerators\, yet radiotherapy began with cobalt-60 teletherapy. On e such technology is called intensity modulated radiotherapy (IMRT)\, whic h can be executed with cobalt-60 teletherapy units to yield dosimetric cha racteristics that are comparable with linear accelerator beams. The lower energy and weaker penetration may be negligible in the delivery of efficie nt IMRT in cobalt-60 teletherapy especially for head and neck cancers with superficial extent. The aim of this study was to investigate the implemen tation of step and shoot technology in cobalt-60 teletherapy.\n\n**Materia ls and Methods**: A clinical MDS Nordion Equinox 80 unit was used at dose rates of 67.7 ± 7.4 cGy/min and 61.4 ± 3.1 cGy/min. Three intensity maps were prescribed with Oncentra 4.3\, and they were verified with GafChromi c EBT2 film measurements in a PTW universal IMRT verification phantom. Two other measurements were made with GafChromic RTQA2-1010 film whilst a phy sical compensator was constructed and placed in the accessory holder. A 0. 125 cc PTW 31010 Semiflex thimble chamber was used for dose rate constancy checks\, and a calibrated Lufft OPUS 20 was used to monitor temperature a nd pressure. Images of post-irradiation films were acquired prior to net o ptical density readouts and normalised lateral beam profile plots. Two-dim ensional gamma index evaluations of the results were made against Monte Ca rlo simulations of three source diameters.\n\n**Results and Discussion**: Film calibration curves showed that GafChromic RTQA2-10101 film had a low dose response than GafChromic EBT2 film. Normalised lateral beam profiles generated from film measurements and Monte Carlo simulations output data r evealed that step and shoot technology can be executed in cobalt-60 teleth erapy by symmetric and asymmetric segmented secondary collimator jaw motio n or by using a three-dimensional physical compensator. Gamma passing rate s were highest between physical measurements and Monte Carlo simulations o f a 1.5 cm diameter source when using 3 mm\, 3 % and 5 mm\, 5 % criteria. Furthermore\, radiochromic film can be a viable tool for dose verification and quality assurance measurements in resultant beam fluence maps.\n\n**C onclusions and Future Recommendations**: Sharply defined beam intensities can be achieved in cobalt-60 teletherapy by a shift to small source diamet ers\, as revealed by the results of Monte Carlo simulations for the smalle st source diameter. Effort is needed to extend this study to the use of mu ltileaf collimation for more complex beam intensity.\n\nhttps://indico.tla bs.ac.za/event/82/contributions/1341/ LOCATION:J Block Auditorium URL:https://indico.tlabs.ac.za/event/82/contributions/1341/ END:VEVENT BEGIN:VEVENT SUMMARY:Development of a spectrometry system for measurement of internal-p air studies DTSTART;VALUE=DATE-TIME:20190320T084500Z DTEND;VALUE=DATE-TIME:20190320T090000Z DTSTAMP;VALUE=DATE-TIME:20260715T222637Z UID:indico-contribution-271-1343@indico.tlabs.ac.za DESCRIPTION:Speakers: Maluba Vernon J. Chisapi (iThemba LABS/Stellenbosch University)\nExcited nuclei eventually de-excites mainly through electroma gnetic transitions\, e.g. gamma-ray transitions or electric monopole (E0) transition in an event that the former is forbidden. E0 transitions procee d via conversion electrons and electron-positron pairs (for transition ene rgies > 1022 keV). Compared to gamma-ray transitions that are predominantl y studied across the chart of nuclides\, a great deal of E0 transitions an d their associated excited 0+ states are still not firmly characterized.\n \nApart from being the only alternative means of unambiguously assigning s pin and parity to states\, E0 transitions also offer a reliable thumbprint for shape coexistence in nuclei\, as the E0 transition strength can be us ed in the calculation of the mixing parameters for shapes suspected to be coexisting. Measurements of E0 transitions also helps elucidate phenomena relating to nuclear compressibility and isotope and isomer shift as well a s provide sensitive tests on various models of nuclear structure [1][2][3] [4].\n\nA new facility\, namely the electron spectrometer\, for measuring E0 transitions was recently commissioned at iThemba Laboratory for Acceler ator Based Sciences (LABS). The current work is aimed at giving the equipm ent new capability by adapting a segmented germanium (LEPS) detector into the spectrometer in order for it to be used to measure e-/e+ pairs of high er (> 3 MeV) energies as well. The LEPS detector is opted for owing to the scarcity (or exorbitant prices if found) of thick segmented Si(Li) detect ors around the globe. The refurbishment is being aided by Geant4 simulatio ns with magnetic field mapped out of the solenoid magnetic lens using OPER A-3D software [5]. The Transmission\, efficiency\, momentum resolution and other parameters of the spectrometer\, obtained using Geant4 simulations\ , will be presented. On-going investigation on the feasibility of using a LEPS detector to measure internal pairs will also be discussed.\n\nOnce th e facility is fully operational\, the physics case will involve measuring E0 transitions in 50Ti\, which will provide information that will subseque ntly be used to investigate the previously suspected existence of admixtur es of 0+ excited states with 2+\, 3+ and 4+ states [6][7][8].\n\nReference s\n[1] Michael Taylor et al. A triplet of differently shaped spin-zero sta tes in the atomic nucleus 186Pb. Nature\, 405:430{433\, 5 2000.\n[2] JL Wo od et al. Coexistence in even-mass nuclei. Physics Reports\, 215(3-4):101{ 201\, 1992.\n[3] Tibor Kibedi and Ray H Spear. Electric monopole transitio ns between 0+ states for nuclei throughout the periodic table. Atomic Data and Nuclear Data Tables\, 89(1):77{100\, 2005.\n[4] JL Wood et al. Electr ic monopole transitions from low energy excitations\nin nuclei. Nuclear Ph ysics A\, 651(4):323{368\, 1999.\n[5] Opera Electromagnetic FEA Simulation Software. Opera-3D software. [Online]. https://operafea.com/\, [Accessed: 28 December 2018].\n[6] DS Oakley et al. Pion elastic and inelastic scatt ering from 48\;50Ti\, 52Cr\,\nand 54\;56Fe at 180 MeV: Determination of ne utron and proton multipole matrix elements. Physical Review C\, 35(4):1392 \, 1987.\n[7] JG Pronko et al. gamma-ray deexcitation of Ti 50 states in t he region of 4-MeV excitation. Physical Review C\, 10(4):1345\, 1974.\n[8] HP Morsch. Monopole transitions in the inelastic 3He-scattering on Ti-iso topes. Physics Letters B\, 47(1):21{23\, 1973.\n\nhttps://indico.tlabs.ac. za/event/82/contributions/1343/ LOCATION:J Block Auditorium URL:https://indico.tlabs.ac.za/event/82/contributions/1343/ END:VEVENT BEGIN:VEVENT SUMMARY:High-Resolution β- - γ Study of the 110Tc – 110Ru – 110Rh – 110Pd Isobaric Decay Chain DTSTART;VALUE=DATE-TIME:20190320T105000Z DTEND;VALUE=DATE-TIME:20190320T110500Z DTSTAMP;VALUE=DATE-TIME:20260715T222637Z UID:indico-contribution-271-1347@indico.tlabs.ac.za DESCRIPTION:Speakers: Shaheen Jazrawi (University of Surrey/National Physi cal Laboratory)\nNeutron-rich nuclei close to mass A=100 display a variety of intriguing shape phenomena such as exotic triaxial shapes\, shape chan ges and shape coexistence. Recent investigations exploiting Coulomb excita tion have helped to shed light on these phenomena [1]. However\, as more i ntense radioactive beams of these refractory isotopes become available it has become evident that some of the key nuclear structure information requ ired to fully analyse this data is lacking.\n\nConsequently\, in conjuncti on with new Coulomb-excitation investigations\, dedicated decay studies we re performed in this mass region. For these studies a cocktail beam of rad ioactive A=110 ions from ANL’s CARIBU source were implanted onto a gold foil and gamma decays were registered with the Gamma-Ray Energy Tracking I n-Beam Nuclear Array (GRETINA) [2]. The analysis of this data will yield n ew information\, refining the level scheme and determining angular correla tion and mixing ratios in these exotic isotopes for the first time. This n ew information is vital for the extraction of nuclear matrix elements and deformation parameters in the Coulomb-excitation analysis. In this talk pr eliminary results will be presented on the discrete-line gamma-ray coincid ence analysis associated with the β-decay feeding of states in 110Ru from 110Tc and subsequent decays along the isobaric chain and these compared w ith the existing literature on this sequence [3\,4].\n[1] D. Doherty et al .\, Phys. Lett. B\, 776\, 334 (2017).\n[2] S. Paschalis et al.\, Nucl. Ins trum. Methods A\, 709\, 44 (2013)\n[3] J.C. Wang et al.\, Phys. Rev. . C61 \, 044308 (2000).\n[4] J. Aysto et al.\, Nuclear Physics \, A515\, 365-380 (1990).\n\nhttps://indico.tlabs.ac.za/event/82/contributions/1347/ LOCATION:J Block Auditorium URL:https://indico.tlabs.ac.za/event/82/contributions/1347/ END:VEVENT BEGIN:VEVENT SUMMARY:Investigation of the beginnings of star formation and the synthesi s of chemical elements in the early Universe DTSTART;VALUE=DATE-TIME:20190320T103500Z DTEND;VALUE=DATE-TIME:20190320T105000Z DTSTAMP;VALUE=DATE-TIME:20260715T222637Z UID:indico-contribution-271-1346@indico.tlabs.ac.za DESCRIPTION:Speakers: Blaine Lomberg (University of the Western Cape)\nMet al-poor stars provide a unique testing ground to investigate the beginning s of star formation and the synthesis of chemical elements in the early Un iverse. In particular\, the abundance patterns seen in these metal-poor st ars provide constraints on the nature of first generation of super-massive stars in the universe. These stars are also characterized by unusual abu ndance patterns of carbon\, nitrogen and oxygen\, which could probably ass ign them as a Population II stars that formed from material chemically enr iched by a first-generation supernova. A parametrical search for best fits suggest a scenario involving low-energy supernova explosions with a relat ively narrow range of masses (10 − 25 solar masses) and little mixing. A lthough this supernova scenario might elucidate the formation of the light elements up to aluminium\, the experimental upper limits currently observ ed for the abundances of heavier elements such as Cr\, Mn\, Co\, Ni and Zn do not allow stronger constraints of the original supernova properties. \ n\nMore puzzling\, however\, is the large abundance of Sr (Z=38) with [Sr/ Fe] +1. Strontium is the only element heavier than the iron group currentl y observed in HE1327-2326. Supposedly\, there are two nuclear-reaction sce narios that could produce Sr:\n\n• The slow-neutron capture\, the s-proc ess\, occurring in asymptotic giant branch (AGB) stars\; how-ever\, this p rocess is inefficient in low metallicity.\n• The main rapid-neutron capt ure\, the r-process\, could also produce strontium in a type-II super-nova \; although the production of Sr is not included in some of the supernova models.\n\nA measurement of the Ba abundance is fundamental to distinguish between the s-process\, with an expected relative abundance of [Sr/Ba] −1\, and the r-process\, with a different ratio of [Sr/Ba] = −0.5 to −0.4. Here we present the first astronomical data for EC20291-3603\, a m etal-poor star observed with the SALT telescope.\n\nhttps://indico.tlabs.a c.za/event/82/contributions/1346/ LOCATION:J Block Auditorium URL:https://indico.tlabs.ac.za/event/82/contributions/1346/ END:VEVENT BEGIN:VEVENT SUMMARY:Uncertainties in Measuring the Lifetime of a Nuclear Excited State via γ–γ Coincidences using NaI(Tl) Scintillators DTSTART;VALUE=DATE-TIME:20190320T092000Z DTEND;VALUE=DATE-TIME:20190320T095000Z DTSTAMP;VALUE=DATE-TIME:20260715T222637Z UID:indico-contribution-271-1331@indico.tlabs.ac.za DESCRIPTION:Speakers: Innocent Lugendo (University of Dar es Salaam)\nMetr ological difficulties in measurement of lifetimes of nuclear excited state s have posed controversies in the quest to answer the fundamental question of whether lifetimes of nuclear states are in variable or not. Although s everal studies have suggested the possibility of slight variations of life times depending on conditions of the nucleus [1\, 2\, 3]\, it is important to note that any claims of non-constancy of lifetimes as a consequence of deviation from the exponential decay curve can only be considered upon ve rification and accountability of stability and uncertainty of the devices used during the experiment [4]. Consequently\, studying the uncertainties in lifetime measurement is a crucial step towards studying the possibility of variation of the lifetimes of nuclear-excited states when the nucleus is subjected to resonance conditions via multiple emission and reabsorptio n of gamma rays. We have\, therefore\, designed a system to precisely meas ure the lifetime of the state via gamma-gamma coincidences using multiple fast scintillators. Measurement uncertainties were thoroughly studied usin g a pair of NaI(Tl) detectors on a simple bench-top setup. All possible so urces of lifetime measurement uncertainties with their magnitudes are pres ented in the uncertainty budget. A measurement uncertainty of 0.661% was o bserved indicating the suitability of the system for observing the variati ons of the lifetime that range from 1% of the known value.\n\nhttps://indi co.tlabs.ac.za/event/82/contributions/1331/ LOCATION:J Block Auditorium URL:https://indico.tlabs.ac.za/event/82/contributions/1331/ END:VEVENT END:VCALENDAR