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[en] The aim of this work was to study photon and electron dose distributions in a phantom filled with water using the Monte Carlo Geant4 tool for electron energies ranging from 1 to 21 MeV and for photon energies ranging from 1.25 MeV to 25 MeV, corresponding to conventional radiotherapy Linac energies. The results of the Geant4 calculations were validated based on the relevant experimental data previously published. The results obtained were fitted and analytical models of dose distributions were developed for gamma radiation and electrons. For each of these models, one-dimensional (including dose depth profiles as a function of the depth inside the phantom) and two-dimensional (including the dose distribution as a function of depth and lateral position inside the phantom) dose distributions have been considered. Results are presented for photons and electrons of various energies. The coefficient of determination R illustrates an excellent match between the developed analytical model and the Geant4 results. It is demonstrated that the analytical models developed in the present study can be applied in various fields such as those used for calibration applications and radiation therapy. It is concluded that the analytical models developed allow for quick, easy and reliable clinical dose estimates and offer promising alternatives to the standard tools and methods used in radiotherapy for treatment planning.
[en] RTE is the mainspring in enhancing energy transition and developing renewable energy in France. To further knowledge on the subject, RTE publishes a detailed inventory of existing and projected wind and photovoltaic installations. This vast overview was achieved with the help of ENEDIS (ERDF), SER (Association of renewable energy industrialists), and ORE Agency (Power network operators). The outstanding facts of this 24. edition of the renewable electricity synthesis are: 50% of renewable energy production capacity are from solar or wind origin. Solar and wind parks power reached almost 28 GW by December 31, 2020. With more than 25.7 GW of installed power, hydroelectricity remains the first renewable energy source in France. The bio-energy power generation park exceeds now 2.1 GW. All sources included, the renewable energy sources have grown by 637 MW during the last quarter 2020, reaching 55.9 GW at December 31, 2020. Power distribution systems are continuously evolving in order to meet the 40% renewable electricity production goal by 2030.
[en] Illustrated by many maps, graphs and tables, this publication proposes a rather detailed overview of the status and development (production and location, employment, sector turnover, market and tariffs) of the different electricity-producing renewable energies: wind energy, photovoltaic energy, hydraulic energy, solid biomass, biogas, renewable urban wastes, geothermal energy, marine energies). This issue includes a chapter on the Regional plan for land use and sustainable development (sraddet), and a regional overview of the different electricity-producing renewable sectors. A focus is proposed for each French region.
[en] Nuclear Energy Data is the Nuclear Energy Agency's annual compilation of statistics and country reports documenting nuclear power status in NEA member countries and in the OECD area. Information provided by governments includes statistics on total electricity produced by all sources and by nuclear power, fuel cycle capacities and requirements, and projections to 2040, where available. Country reports summarise energy policies, updates of the status in nuclear energy programs and fuel cycle developments. In 2020, the Covid-19 pandemic has highlighted the importance of electricity security in modern societies. Although the long-term implications for electricity generation are difficult to assess, during the crisis nuclear power continued to support the security of supply and has been, together with renewables, one of the most resilient electricity sources. In 2019, nuclear power continued to supply significant amounts of low carbon baseload electricity, despite strong competition from low-cost fossil fuels and renewable energy sources. Governments committed to having nuclear power in the energy mix advanced plans for developing or increasing nuclear generating capacity, with the preparation of new build projects making progress in countries such as Finland, Hungary, Turkey, the United Kingdom and Russia. Further details on these and other developments are provided in the publication's numerous tables, graphs and country reports. This publication contains 'StatLinks'. For each StatLink, the reader will find a URL which leads to the corresponding spreadsheet. These links work in the same way as an Internet link
[fr]Les Donnees sur l'energie nucleaire, compilation annuelle de statistiques et de rapports nationaux preparee par l'Agence de l'OCDE pour l'energie nucleaire, presentent la situation de l'energie nucleaire dans les pays membres de l'AEN et dans la zone de l'OCDE. Les informations communiquees par les gouvernements comprennent des statistiques sur la production d'electricite totale et nucleaire, les capacites et les besoins du cycle du combustible et, lorsqu'elles sont disponibles, des projections jusqu'en 2040. Les rapports nationaux proposent une synthese des politiques energetiques, de la situation des programmes electronucleaires et des evolutions du cycle du combustible. En 2020, la pandemie de COVID-19 a mis en avant l'importance de la securite de l'approvisionnement en electricite dans nos societes modernes. S'il est difficile d'evaluer les consequences a long terme sur la production d'electricite, on observe que, pendant la crise, l'energie nucleaire a continue de soutenir la securite d'approvisionnement et demeure, avec les renouvelables, l'une des sources d'electricite les plus resilientes. En 2019, les centrales nucleaires ont continue de fournir de grandes quantites d'electricite en base faiblement carbonee, et ce dans un contexte de forte concurrence avec les combustibles fossiles bon marche et les energies renouvelables. Les pays decides a inclure ou conserver le nucleaire dans leur bouquet energetique ont poursuivi leurs projets de deploiement ou d'augmentation de leur puissance nucleaire installee. Ainsi, des projets de construction progressent en Finlande, en Hongrie, au Royaume- Uni, en Russie et en Turquie. De plus amples informations sur ces evolutions et d'autres developpements sont fournies dans les nombreux tableaux, graphiques et rapports nationaux que contient cet ouvrage. Cette publication contient des 'StatLinks'. Fonctionnant comme un lien internet, un StatLink fournit l'acces a la feuille de calcul correspondante
[en] This publication presents the bio-methane industry situation of continental France during the Fourth quarter 2020: bio-methane production facilities (number, production capacity per type of facility), annual and quarterly evolution of production capacities, pending projects with their expected capacities, evolution of quarterly production, regional distribution and evolution of biomethane facilities with their maximum production capacities and the share injected into the gas distribution system, regional distribution of pending projects with their expected maximum production capacities.
[en] After a synthesis of the 4. quarter 2020 news and a focus on the implementation of the French solar energy development plan 'PlaceAuSoleil', this publication presents in a series of graphs the situation of photovoltaic energy development in France and in the whole world: evolution of the world's photovoltaic park (new and cumulated capacities), world comparison of production costs of new power generation capacities, photovoltaic power generation in France (photovoltaic share in the French power consumption, new connected capacities per surface size and for self-consumption, evolution of connected capacities rate, self-consumption market trend, residential market analysis and feed-in tariffs per surface size, pending projects, evolution of feed-in tariffs in continental France, extra public burdens induced by new connections with respect to surface size.
[en] In this paper, the embedded-atom method was used to study the influence of different solute elements (Co,Cu,Yb) on the thermophysical properties of liquid Ni-based alloys. By exploring the relationship between surface tension, viscosity, diffusion coefficient and temperature of liquid Ni-based alloys with three solutes in the range of 1500~1900 K, we found that under certain components the surface tension of liquid Ni-based alloys with three solutes decreased as temperature increased. Except the case that the atomic radius of the same period decreased with the increase of the atomic number and influence of lanthanide and actinide contraction, the surface tension of liquid Ni-based alloys decreased with the increase of atomic number. The viscosity of liquid alloy showed a downward trend with increasing temperature, and the viscosity decreased exponentially with the temperature increasing under certain components. The variation trend of diffusion coefficient of the three kinds of atoms was similar to that of the temperature, which increased with the increase of temperature under the same component. Especially, the diffusion coefficient increases exponentially with the increase of temperature under certain components. These simulated data provided necessary thermophysical parameters for non-equilibrium dynamics analysis of liquid-phase alloys and also supplied a sound theoretical basis for exploring the internal physical mechanism of "liquid microstructures–thermophysical properties–preferred phase of nucleation".
[en] We use the method of light-cone sum rules to study decay properties of P-wave bottom baryons belonging to the SU(3) flavor 6 representation. In Cui et al. (Phys Rev D 99:094021, 2019) we have studied their mass spectrum and pionic decays, and found that the Σ(6097) and Ξ(6227) can be well interpreted as P-wave bottom baryons of J=3/2. In this paper we further study their decays into ground-state bottom baryons and vector mesons. We propose to search for a new state Ξ(5/2), that is the J=5/2 partner state of the Ξ(6227), in the Ξ(5/2)→Ξρ→Ξππ decay process. Its mass is 12±5 MeV larger than that of the Ξ(6227).
[en] The hypothesis of the present investigation underlined with determination of possible synergistic effects of serpentine mineral additive on LiBO glasses. A group of LiBO glasses with serpentine mineral additive were synthesized by melt-quenching technique. The elemental analysis of two different LiBO glasses with different amount of serpentine additive is tested using energy-dispersive X-ray (EDX) technique. Next, the surface morphology of synthesized serpentine glasses was investigated with scanning electron microscopy (SEM). The optical features of synthesized serpentine glasses were determined along the wavelength ranged from 200 to 900 nm. Lastly, nuclear radiation shielding properties of LiBO glasses with serpentine mineral additive were determined for gamma rays, neutrons and charged particles. MCNPX (version 2.6.0) general-purpose Monte Carlo code has been utilized for mass attenuation coefficients calculations. The results showed that the spectra are decreasing with wavelength with an observed peak centered at 450 nm. Moreover, it is observed that serpentine mineral additive improves the gamma protecting capacity of LiBO glasses. It was also noticed that the addition of serpentine mineral also enhanced the neutron and charged particle absorption of the glasses.
[en] For 25 LiO–(75 − x) BO–x BiO (where x = 0, 5, 10, 15, 20, 25, 30, 35, and 40 mol%) glasses, gamma-ray and neutrons attenuation features were explored by theoretical approach using ParShield/WinXCOM program, Geant4, and Penelope codes. At Ba (276, 303, 356, and 384 keV), Na (511 and 1280 keV), Cs (662 keV), Mn (835 keV), and Co (1170 and 1330 keV) photon peaks, for all samples, mass attenuation coefficient (μ/ρ), effective atomic number (Z), effective electron density (N), half-value layer (HVL), and mean free path (MFP) parameters have been evaluated using ParShield/WinXCOM program. The μ/ρ values computed by WinXCOM, Geant4, and Penelope codes were compared to check the accuracy, and satisfactory agreement among the values was identified. Moreover, using G–P fitting method as a function of penetration depth (1, 5, 10, 15, 20, 25, 30, 35, and 40 mfp) within the photon energy range of 0.015–15 MeV, exposure buildup factor (EBF) and energy absorption buildup factor (EABF) were derived. For all selected glasses, the effectiveness of the neutrons attenuation has been discussed in terms of macroscopic effective removal cross-section (Σ), coherent scattering cross-section (σ), incoherent scattering cross-section (σ), absorption cross-section (σ), and total neutron cross-section (σ). The 'σ' values have been calculated within 10–10 MeV neutron energy range using the Geant4 code. The μ/ρ possessed larger values at the lowest energy and lower values at higher energy regions for all studied glasses. The μ/ρ, Z, HVL, and MFP values showed enhanced γ-ray shielding capability with BiO content increment in the samples. The 25 LiO–35 BO–40 BiO (mol%) sample by having larger Z and/or Z value, faired lower EBF and EABF values. Largest μ/ρ and Z, and minimal HVL, MFP, EBF, and EABF values of 25 LiO–35 BO–40 BiO (mol%) glass demonstrated its superior γ-ray attenuation ability among all examined glasses. Further, among all glasses, 25 LiO–75 BO (mol%) sample exhibits relatively higher Σ (0.11326 cm) and ‘σ’ (46.109 cm → 0.84607 cm from 1 × 10 MeV → 1×10 MeV neutron energy) values for fast and thermal neutrons attenuation, respectively, indicating its better neutrons absorption competence.