Internal dosimetry deals with the measurement of the radiation dose absorbed internally by an organ after the administration of isotopes for diagnosis and treatment. The purpose of this research was to evaluate bladder-urine transfer coefficient impact on the bladder technetium activity in the MIRD bio kinetic model and propose a simplified biokinetic model using the ICRP 134 model. The residence time in the bladder and kidneys was determined using scans of five volunteer patients at three different time points (1 h, 2 h, and 3 h post-injection). To quantify activity in the kidneys and bladder, the conjugate-view method was applied to the imaging data. In the present study technetium activity has been calculated in human organs using the MIRD et ICRP bio-kinetic models. The theoretical results were obtained by simulation on the MatLab software of the matrix equations obtained from different equations of the quantity of technetium in the different organs used in the bio-kinetic models. The study showed that it is important to take into account the transfer coefficient between the bladder and urine to reduce the fraction of technetium in the bladder. The ICRP model and the proposed simplified model predict technetium fractions better than the MIRD model three hours after injection. The study also showed that the ICRP model and the proposed simplified model are in agreement in predicting the technetium fraction in the bladder and kidneys.
In the literature, there are several theoretical and experimental methods for calculating the resonance energies and natural widths of atomic systems. For the 1s22s2p6np ¹P1 series of Ne, Na+, Mg2+, and the 1s2s22p5np ¹P1 series of Ne+, various methods have been employed. In this present work, resonance energies resonance energies and width of the 1s22s2p6 np 1P1 series of the Ne, Na+, Mg2+, and 1s2s22p5 np 1P1 of Ne+ ions are calculated. The energies are calculated in the framework of the Modified Atomic Orbital Theory (MAOT). The results obtained compared very well with theoretical and experimental literature values. The possibility to use the MOAT formalism report rapidly with an excellent accuracy the position of the resonances as well as their width within simple analytical formulae is demonstrated. It is demonstrated that the MOAT-method can be used to assist fruitfully experiments for identifying narrow resonance energies. Thus, our results can be used as reference data for the interpretation of atomic spectra for the diagnosis of astrophysical and laboratory plasma. Through this method new values of these energies are reported going up to n=40. These excellent agreements between theory and experiments indicate that the MAOT formalism can be used to report accurate high-lying excited Rydberg series of atomic species for the diagnostic and the modeling of astrophysical or laboratory plasmas.
Water contamination by heavy metals and radionuclides poses a major environmental and public health concern due to their toxicity, persistence, and bioaccumulation potential. This study aimed to assess the contamination levels of water sources near industrial, automobile, and residential areas in Gboko, Nigeria. Specifically, the concentrations of heavy metals such as lead (Pb), cadmium (Cd), chromium (Cr), iron (Fe), and zinc (Zn), as well as naturally occurring radionuclides including 226Ra, 232Th, and 40K, were analysed in borehole, well, and stream water samples. Results showed that residential areas generally had metal concentrations below WHO permissible limits, while automotive and industrial areas recorded higher levels, especially for Pb, Cd, Cr, and Fe. Lead levels in industrial streams reached 0.04 mg/L, exceeding WHO standards, with potential long-term health risks such as neurological damage and kidney dysfunction. Radionuclide activity was highest at the industrial sites, with Total Annual Effective Dose (TAED) values ranging from 0.00146 to 0.00221 mSv/year, which, although within WHO safety limits, approached the Excess Lifetime Cancer Risk (ELCR) thresholds. The elevated contamination levels in industrial and automotive areas were attributed to emissions from vehicular activities, industrial discharges, and surface runoff carrying pollutants into water bodies. Overall, while zinc concentrations remained within safe limits across all sites, the presence of other heavy metals and increasing radionuclide activities in industrial areas indicate a growing pollution burden. The study concludes that periodic monitoring and implementation of pollution control measures are essential to mitigate the potential health hazards associated with contaminated water sources in Gboko, thereby ensuring the safety of residents who rely on these water supplies for domestic and drinking purposes.
Maintaining effective border security against the threat of nuclear and radiological materials is a critical challenge, requiring the development of advanced detection technologies and integrated security systems. This review examines the key challenges, innovative approaches and future research priorities in the field of radiation detection and interdiction for border security applications. To address these challenges, the review highlights a range of innovative technological advancements, such as the use of high-performance radiation detectors, spectroscopic identification techniques, active interrogation methods, and automated screening systems enhanced by artificial intelligence and data fusion. Furthermore, the review explores the development of mobile and deployable detection systems, as well as the integration of multi-modal approaches that combine different sensor technologies to create more comprehensive and robust border security solutions. Looking to the future, the paper identifies key research priorities, including improving sensor performance, enhancing material identification and categorization, leveraging AI and machine learning, strengthening system resilience and adaptability, and promoting international cooperation and information sharing. By addressing these critical areas, the research community and border security agencies can work together to enhance the protection of global borders against the persistent threat of nuclear and radiological materials, ultimately contributing to the broader goal of strengthening global nuclear security.
This research article presents a novel theoretical framework that elucidates the formation of non-thermal radiation emitted by black holes, specifically focusing on two distinct quantum metaparticles: axion photon-hadronic metaparticles and aspecton lepton-hadronic metaparticles. These metaparticles are theorized to emerge under extreme spacetime compression conditions prevalent within the event horizons of black hole singularities. By leveraging principles from quantum harmonic resonance dynamics, quantum tunneling phenomena, and subspace ether theory, this study posits that axion metaparticles are coherent wave-packet superstring vibrations formed through the unification of hadron-photon interactions in regions of intense spacetime compression. In contrast, aspecton metaparticles arise from lepton-hadron interactions, characterized by fluctuating electric charge polarities that induce non-uniform oscillatory propagation trajectories. The theoretical constructs presented herein are supported by recent observational data from Fermi-LAT and LIGO, which align with the proposed mechanisms of metaparticle emissions. This research further integrates the findings within the context of eleven-dimensional grand-unified subspace field theory, offering a comprehensive understanding of the quantum processes at play in black hole environments. The implications of this work extend to the broader astrophysical landscape, providing insights into the nature of dark radiation and the potential for new particle detection methodologies. By establishing a connection between quantum harmonic resonance and the emissions from stellar singularities, this paper contributes to the ongoing discourse in theoretical physics regarding the unification of fundamental forces and the quest for a coherent understanding of the universe's underlying fabric.
In the literature, there are several theoretical and experimental methods for calculating the resonance energies and natural widths of atomic systems. For the 1s22s2p6np ¹P1 series of Ne, Na+, Mg2+, and the 1s2s22p5np ¹P1 series of Ne+, various methods have been employed. In this present work, resonance energies resonance energies and width of the 1s22s2p6 np 1P1 series of the Ne, Na+, Mg2+, and 1s2s22p5 np 1P1 of Ne+ ions are calculated. The energies are calculated in the framework of the Modified Atomic Orbital Theory (MAOT). The results obtained compared very well with theoretical and experimental literature values. The possibility to use the MOAT formalism report rapidly with an excellent accuracy the position of the resonances as well as their width within simple analytical formulae is demonstrated. It is demonstrated that the MOAT-method can be used to assist fruitfully experiments for identifying narrow resonance energies. Thus, our results can be used as reference data for the interpretation of atomic spectra for the diagnosis of astrophysical and laboratory plasma. Through this method new values of these energies are reported going up to n=40. These excellent agreements between theory and experiments indicate that the MAOT formalism can be used to report accurate high-lying excited Rydberg series of atomic species for the diagnostic and the modeling of astrophysical or laboratory plasmas.
Rwanda, just like many other developing countries, still faces challenges in the energy sector. The country is still not able to supply reliable and affordable electricity to meet the current and future energy needs, as a result of rapid economic growth, increasing population and urbanization. Rwanda currently has limited generation resources, particularly during the dry season, when several hydropower stations are experiencing water shortages. Sometimes, leased diesel generation is needed to meet peak demand, which comes at a hefty cost. Efforts are being made to determine the true number of existing resources in the country for energy generation. Diversifying sources of energy inevitably becomes a strategic option. Rwanda has decided to embark on an ambitious programme for nuclear development as one of the alternatives to tackle energy challenges. This paper briefly presents plans featuring in the nuclear science and technology programme with the ultimate goal to leverage nuclear applications for sustainable social-economic development. A review of the country’s energy sector status is presented with focus on prospects of the nuclear programme as the solution to the country’s high energy demand and applications in different socio-economic sectors. In efforts to join the rest of world in the “net zero” greenhouse gas emission by 2050, Rwanda embraces the perspective under which nuclear energy is foreseen as a source of energy that most supports the efforts.
The In-situ measurement of background ionizing radiation of Centre of Life hospital Bori in Khana Local Government Area of Rivers state of Nigeria has been carried out. Digilert-200 Radiation meters was utilized in measurement of background ionizing radiation and Global Positioning System (Garmin 765) was used in measuring coordinates of the sampling points. Fifteen (15) sampling points were arbitrarily selected within the diagnostics centre. The results of the BIR outdoor and indoor varies from 0.010 - 0.015 with mean of 0.013 mRhr-1. Absorbed Dose rate varies from 87.0 -130.5 nGy/yr with mean of 114.3 nGy/yr and 116.0 nGy/yr for outdoor and indoor. AEDE varies from 0.107 – 0.160 with mean of 0.140 mSv/yr and 0.142 mSv/yr and Excess life cancer risk varies from 0.37×10-3 – 0.56×10-3 with mean of 0.50×10-3 and 0.50×10-3 for outdoor and indoor respectively. The obtained values for BIR of Centre of Life Hospital Ltd was within recommended standard limit of 0.013mR/h. The obtained result for AEDE was within the recommended safe limit. The obtained results of ELCR and the ADR are all higher than the recommended standard of 0.29 x 10-3 and 84.0 nGy/h respectively. The result of radiation dose to different body organ shows that the testes have the highest radiation percentage for outdoor and indoor respectively.
Safe, simple and soon deployable are the imperatives for each SMR concept today. Only this SMR has the potential to become a nuclear workhorse in the fight against climate change if it is available soon, in large numbers and deployable worldwide. Therefore the assessment of the usefulness of an SMR concept must not only relate to the reactor itself. Only a holistic view of the entire nuclear fuel cycle with the given SMR as the central part between the front-end and back-end can lead to viable decisions. The IAEA lists more than 120 SMR concepts in its Handbook 2022. Time pressure is forcing us to critical selection of a promising reactor concept and to combine innovative solutions with tried and established technical and administrative networks. Against this background, the Modified CANDU Reactor (MCR) is proposed as additional SMR design. The MCR has two obvious modifications compared to the well-known and globally proven CANDU design: a) spherical fuel elements (pebbles) with ceramic cladding b) vertical arrangement of the pressure tubes. Intended for the generation of heat and electricity close to the consumer, the construction of a plant with MCR is preferably carried out underground close to the surface. The Herrenknecht VSM-shaft-tunnel technology is planned for the construction of the structures. For the transportation of irradiated fuel elements, (extended) interim storage and final disposal, technologies are proposed (Initial Barrier; TRIPLE C) that have already been published elsewhere. In order to provide a basis for further scientific and technical discussions, an attempt was made to incorporate the MCR concept into the existing CANDU SMR TM design. The resulting combined “overlapping” concept has not yet been discussed with the CANDU developing and operating countries. The authors hope for a fruitful discussion and are looking for future cooperation with the CANDU SMR TM manufacturer (CANDU Energy Inc. Canada), as well as with the countries that traditionally use CANDU reactors (China, India, South Korea) and Norway in future maybe too.
X-rays have an undeniable advantage in medicine, especially for diagnosis. However, their use is not without risk. Following numerous studies carried out by the International Atomic Energy Agency and learned societies, it has been recommended to strengthen the principle of optimization in diagnostic radiology by implementing Diagnostic Reference Levels. The purpose of this study is to determine diagnostic reference levels (DRLs) in order to evaluate radiological practices and to reduce doses received by patients for frontal chest examination at the Bingerville Mother-Child Hospital (MCH). The work was carried out on a sample of 110 patients at the Mother and Child Hospital in Bingerville. We used a generator and a tube for the production of X-rays. The dose-area product (DAP) value was obtained using a dose calculator built into the generator. The determination of the DRLs in DAP (cGy.cm²) was made with the 75th percentile statistical method and yielded the following result of 14.32 cGy.cm². Comparing our DRL value with those obtained elsewhere, as well as comparing the median DAP from the present study with the DRLs in Abidjan and at the national level, radiological practices are satisfactory for frontal chest examination. However, after analysis of some radiological parameters used, it appears that efforts need to be made by acting on the kV, mAs, diaphragm and the filtration.
The most frequently used radiopharmaceutical for treatment of thyroid cancer is the radioactive iodine (RAI). Patients treated with RAI therapy cause risk of external radiation exposure to the public and family members. While the therapeutic use of iodine-131 for thyroid carcinoma patients offers enormous benefit to them, it contributes also significantly to the radiation exposure of individuals and population. Patients treated with radioiodine present a radiation hazard and precautions are necessary to limit radiation dose to the relatives and the members of the public. The study aims to develop guidelines for the release of thyroid cancer patients treated with I-131. For this purpose, simulations were performed for estimating suitable period of restriction during which close contact with the patient should be disallowed and limited. These simulations are based on the French working Group and the recommendations of the International Commission on Radiation Protection. The study was carried out at the Isotopes Laboratory (LRI), Department of Nuclear Medicine in Antananarivo, Madagascar. According to the current regulation in radiation protection in Madagascar, the dose limit for the members of the public is limited to 1 mSv. Guidelines for discharge from the hospital are as follows. Patients can travel using public transportation up to 15 minutes. Patients are suggested to sleep apart and restrict contact with partner for 4 days after leaving the hospital. Contact with children should be restricted according to their ages. Time to restrict contact with child ranging from 3 to 10 years is limited to 4 days, and up to 7 days for younger children. This guideline is based on the retained activity of 800 MBq or the external dose rate is less than 40 μSv/h at 1 m. For public transportation, the suggested travel times for thyroid cancer are similar to those recommended by the French group. The length of time for which patients are in contact with children in this study is widely less than recommendations by French Group.
Gamma-ray spectrometry (GRS) is an exploration technology that distinguishes itself from other non-contact sensing technologies because it provides information from 30 to 50 cm below the ground. This technology has evolved through three significant turning points in mapping output. The first turning point, in the 1960s-1970s, was the transition from U concentration maps to weathered zoning maps utilizing K or eTh. The second turning point, occurring from the 1980s to 1990s, was marked by the application of radionuclide mapping to assess radioactive contamination. A third turning point, in the early 2000s, was the development of soil maps for precision agriculture, supported by the free statistics software R. This paper reviews advances in gamma-ray spectrometry spectral analysis since 2000. Traditionally, the gamma-ray spectrum is depicted as a two-dimensional graph with energy on the horizontal axis and counts on the vertical axis. The NASVD and MNF methods, developed around 2000, necessitate a reevaluation of this concept. By conducting principal component analysis of the gamma-ray spectrum in hyperspace, these techniques have unveiled new spectra, such as ground and sky spectra, and have facilitated the removal of noise components from the gamma-ray spectrum. Naturally occurring gamma-ray spectra typically exhibit energies ranging from 0.04 to 3 MeV. Observations from fusion reactors measure energies up to 20 MeV for diagnostics of nuclear plasma. These spectra may yield valuable insights when applied to innovative statistical analysis techniques. A comprehensive spectral analysis method developed in the early 2000s has demonstrated the potential to extract a variety of information beyond window nuclides, previously unexplored. The regression coefficient plots from the PLSR regression model have revealed novel spectral images. This model is set to influence future research on GRS by expanding the number of objectives and covariates. The innovative calibration method for full-spectrum analysis, which assesses different concentration areas, has proven that calibration is achievable even in the absence of a calibration pad. It is expected to become a formidable approach for spectrum analysis in the upcoming period.
The presence of radioactivity, originating from both natural and human-induced sources, is widespread in varying degrees throughout the Earth's crust. Soil, as a fundamental component of the Earth's crust, serves as an ongoing source of exposure to humans. The level of radioactivity in soil is influenced by factors such as soil composition and land usage. It is expected that barren soil exhibits distinct radioactivity levels compared to cultivated soil. To investigate the radioactivity levels within barren soil, a study was conducted on approximately 11 hectares of soil samples located in Niankhene. Utilizing gamma ray spectrometry methodology with a high purity germanium gamma-ray detector, activity concentration levels of radionuclides including 40K, 137Cs, 226Ra, and 232Th were evaluated. A total of 16 soil samples were collected at depths ranging from 0 to 40 cm with 20 cm intervals. The activity concentrations of the radionuclides were observed as follows: 40K ranged from below the limit of detection to 34.7 Bq.kg-1; 137Cs varied from 0.06 to 0.80 Bq.kg-1; 226Ra measured was between 7.49 and 101.56 kg-1; and 232Th ranged 0.33 and 12.68 Bq.kg-1. The total dose radiation exposure were 27 nGy/h in this study. Before conducting radiometric measurements, chemical analyses were performed to determine the concentrations of Na, Ca, and Mg, along with measurements of electrical conductivity and pH levels of the soil samples.
Published theoretical data from several models: PHSD and HSD both with and without chiral symmetry restoration (CSR), applied to experimental data on nuclear collisions from BEVALAC and SIS to LHC energies were analyzed using meta-analysis and Kolmogorov criteria. This made it possible to localize possible features of nuclear matter created in central nucleus-nucleus collisions. Ignition of a drop of quark-gluon plasma (QGP) begins already at an energy of about √(s_NN) = 2 GeV. We estimate that this QGP droplet occupies a small fraction, 15 % (average radius of about 5.3 fermi if the fireball radius is 10 fermi) of the total volume of the fireball created at √(s_NN) = 2.7 GeV. A drop of exotic matter undergoes a split phase transition: separated boundaries of sharp (1st order) crossover and CSR in chiral limit, between QGP and Quarkyonic matter at an energy about √(s_NN) = 3.5 GeV. The critical endpoint of 2nd order probably cannot be reached in nuclear collisions. The triple phase area occupies interval from √(s_NN) = 12 GeV to 15 GeV, the critical endpoint of 1st order at around √(s_NN) = 20 GeV. The boundary of smooth (2nd order) crossover transition with CSR in chiral limit between Quarkyonic matter and QGP was localized between √(s_NN) = 9.3 GeV and 12 GeV, and between Hadronic and QGP in the interval from √(s_NN) = 15 GeV to 20 GeV, the boundary of sharp (1st order) crossover transition with CSR in chiral limit between Hadronic matter and QGP was localized after √(s_NN) = 20 GeV. The phase trajectory of the hadronic corona, enveloping the exotic droplet, always remains in the hadronic phase.
RCC-M M5110 is the procurement code for rolling or forging bars for bolts and drive rods of class 1, 2 and 3 equipment of nuclear power plants. The individual high strength steels involved in this specification specify only the minimum hardness of the material and have no limit on the maximum hardness. The material selection of major components of nuclear power machinery equipment must meet the requirements of load bearing and safe operation, and ensure sufficient strength and hardness, which is especially important for the material selection of connecting bolts and driving rods of nuclear power equipment. As the strength and hardness of high strength steel increase, the plasticity and toughness of materials decrease sharply, as do the mechanical properties and corrosion resistance, increasing the risk of bolt fracture and equipment damage. In order to ensure the strength and hardness of metal materials, it is necessary to consider the comprehensive mechanical properties and corrosion resistance of the material, including resistance stress corrosion cracking (SCC). Improving strength and hardness should not be the only goal of improving the performance of metal materials. In the formulation and selection of raw material standards, the mechanical properties of important equipment materials, such as hardness, must be limited. To meet the requirements of "redundant design" and "defense in depth" of nuclear power equipment. This paper will discuss how to reunderstand the the hardness limits of RCC-M M 5110 materials.
South Africa requires safe affordable distributed base load energy, one way to achieve this is to use nuclear power integrated with renewable energy sources on a decentralized basis.This suggests the development of its own micro modular nuclear reactor, to supply energy to towns, small communities, mines and processing plants.Large Light Water Reactors (LWRs) are expensive and require a large infrastructure development.A High Temperature Reactor (HTR) called the Advanced Micro Reactor (AMR) is in the process of being developed and the design philosophy is to design for inherent safety, maximally using technology that has been developed and validated in previous HTR programs albeit in a completely different and unique configuration.The concept is based on existing knowhow and experience/expertise in South Africa during the time of the Pebble Bed Modular reactor (PBMR) project.These AMR reactors are to be factory built to obtain good quality control and rolled out to various sites.Once the reactor has reached its end of life, it would be returned to a licensed organisation for refuelling.The AMR produces 10MW of thermal power.The reactor configuration uses hexagonal graphite blocks for structural and moderator material, which are arranged to form a cylindrical core layout.The fuel assemblies are silicon carbide tubes that house coated particle fuel, immersed in a lead-bismuth eutectic alloy (LBE).Each fuel assembly is contained in a boring within the graphite moderator that allows an annulus for cooling.There are 420 fuel assemblies in the core.Low enriched fuel in the form of UO 2 or UCO is used.Helium gas is used as coolant.The coolant enters the core at 450°C and exits at 750°C.The mechanical, neutronic and thermal-hydraulic design of the AMR, is being evaluated with assistance from STL Nuclear (Pty) Ltd., the University of Pretoria (UP), the North-West University and the South African Nuclear Energy Corporation (NECSA).The OSCAR-5 code package, together with the Serpent neutronic code were used to perform the basic neutronic studies while the Flownex package was used to determine the thermal-hydraulic and safety evaluation for the Design Base Accident (DBA) specifically the Depressurized Loss of Forced Cooling (DLOFC) event.
The article considers a way to compare large bulks of experimental data with theoretical calculations, in which the quality of theoretical models is clearly demonstrated graphically. The main idea of the method consists in grouping physical observables, represented by experiment and theoretical calculation, into samples, each of which characterizes a certain physical process. A further choice of a convenient criterion for comparing measurements and calculations, its calculation and averaging within each sample and then over all samples, makes it possible to choose the best theoretical model in the entire measurement area. Published theoretical data of the three-fluid dynamic model (3FD) applied to the experimental data from heavy-ion collisions at the energy range $\sqrt{s_{NN}}\,=\,2.7 - 63$ GeV are used as example of application of the developed methodology. When analyzing the results, the quantum nature of the fireball, created at heavy ion collisions, was taken into account. Thus, even at energy $\sqrt{s_{NN}}\,=\,63$ GeV of central collisions of heavy ions, there is a nonzero probability of fireball formation without ignition of the quark-gluon plasma (QGP). At the same time, QGP ignition at central collision energies above at least $\sqrt{s_{NN}}\,=\,12 GeV occurs through two competing processes, through a first-order phase transition and through a smooth crossover. That is, in nature, these two possibilities are realized, which occur with approximately the same probabilities.
Within the framework of the European research activities devoted to design the DEMO breeding blanket (BB), the Water-Cooled Lithium-Lead (WCLL) BB concept is one of the candidates currently assessed in EU. One of the main issues connected to its design is represented by the remote maintenance (RM) operations. In particular, previous thermo-mechanical analysis highlighted a Ductile to Brittle Transition Temperature (DBTT) shift above the room temperature within the WCLL central outboard (COB) segment during normal operation. This may pose problems during the RM operations foreseen in the BB replacement phase. Indeed, within those WCLL COB segment’s regions where the DBTT shifted above the room temperature, the stress level arising during RM operations may be able to promote crack growth and migration resulting in a fragile fracture event. Then, in this work, the structural assessment of the DEMO WCLL COB segment under RM scenarios is performed, in order to provide the fracture mechanics analysis with the necessary input in terms of stress spatial distribution and to understand if the deformation occurring during RM can be accommodated by the available space reservation. Several potential RM scenarios have been considered, taking into account also the potential occurrence of a seismic event or the necessity to remove the WCLL COB segment with the liquid breeder not drained. The study has been performed adopting a numerical approach based on the Finite Element Method and adopting the quoted Abaqus code. The obtained results are quite encouraging and will allow, in the follow up, the refinement of the RM plan foreseen for the WCLL BB.
In this present work, resonance energies and excitation energies of doubly 1,3P° excited states of the helium isoelectronic sequence are calculated. The doubly excited states investigated are labelled in the (K, T, A) classification scheme. The energies are calculated in the framework of the variationnal procedure of the Screening constant by unit nuclear charge (SCUNC) formalism. The results obtained compared very well with theoretical and experimental literature values. The possibility to use the SCUNC formalism report rapidly with an excellent accuracy the position of the excitation resonances as well as their width within simple analytical formulae is demonstrated. It is demonstrated that the SCUNC-method can be used to assist fruitfully experiments for identifying narrow resonance energies. Thus, our results can be used as reference data for the interpretation of atomic spectra for the diagnosis of astrophysical and laboratory plasma. In the present work, a new correlated wave function is presented to express analytically the resonance energies and excitation energies of doubly 1,3P° excited states in the He-like systems.
The motivation of the diagonalization method is to take into consideration the coupling between closed and opened channels in term of perturbation theory and to neglect the indirect coupling as well but also the autoionisation states through the opened channels. This procedure leads to a relatively simple mathematical problem consisting of solving a system of linear algebraic equations instead of a system of coupled differential equations or integro-differential equations. In this paper, we will focus on the Resonance positions, Partial and total widths for the autoionization into various decay channels of some 1,3L° doubly excited states of helium-like oxygen ion O6+ converging on the N=5 hydrogenic thresholds are reported for L=1, 2, 3, 4, 5, 6 and 7. The calculation was made in the framework of the diagonalization method approximation in LS coupling scheme. The partial widths for multi-channel autoionizing levels to sublevels of O7+ are calculated by neglecting the direct coupling between the open channels. We were able to find results consistent with some in the literature. It is about the configuration P, D, F, G, H, I and K. We could see that the decays are relatively dependent on the ionization thresholds of the residual ion O7+. Some analyses are made on these resultast and only according to the level of decay focused in this paper then made a surplus in the framework of nuclear spectroscopy.
