Progress in reducing ICRF-specific impurity release in ASDEX upgrade and JET

Use of new 3-strap ICRF antennas with all-tungsten (W) limiters in ASDEX Upgrade results in a reduction of the W sources at the antenna limiters and of the W content in the confined plasma by at least a factor of 2 compared to the W-limiter 2-strap antennas used in the past. The reduction is observed with a broad range of plasma shapes. In multiple locations of antenna frame, the limiter W source has a minimum when RF image currents are decreased by cancellation of the RF current contributions of the central and the outer straps. In JET with ITER-like wall, ITER-like antenna produces about 20% less of main chamber radiation and of W content compared to the old A2 antennas. However the effect of the A2 antennas on W content is scattered depending on which antennas are powered. Experiments in JET with trace nitrogen (N 2 ) injection show that a presence of active ICRF antenna close to the midplane injection valve has little effect on the core N content, both in dipole and in -90 °phasing. This indicates that the effect of ICRF on impurity transport across the scape-off-layer is small in JET compared to the dominant effect on impurity sources leading to increased impurity levels during ICRF operation.EURATOM 633053US Department of Energy DE-AC05-00OR2272

Contradictions in the Development of the Welfare Non-Profit Sector in Russia

Received 28 April 2023. Accepted 8 August 2023. Published online 6 October 2023.The article focuses on the core contradictions within the development of the social non-profit sector in Russia. The empirical basis of the study comprises statistical data, legal documents regulating the social services’ sphere, research data from previous studies conducted in Russia, as well as qualitative data collected for this study. The introduction provides background information on the stages of reforming the social service system in Russia. The first part is devoted to the contradictions between international trends and Russian patterns. In line with a neoliberal approach, non-profit NGOs play a significant role as key actors in social work providing social services for different client groups. At the same time, they are not independent and Russian civil society is not yet strong enough to realize social rights of citizens. In the next section, some of the key issues of interaction between the government and NGOs are discussed. An analysis of the current situation demonstrates that while a social partnership between the state and NGOs is affirmed by authorities on official level, in practice, the state still dominates the social sector. The article then focuses on how Russian NGOs have reoriented their efforts toward financial sustainability through government support.This work was supported by the Russian Science Foundation (RSF) under the project No. 19–18–00246-P, titled “Challenges of the transformation of welfare state in Russia: institutional changes, social investment, digitalization of social services”, implemented at St. Petersburg State University

Bis(acetyl­acetonato-κ2 O,O′)(2-amino-1-methyl-1H-benzimidazole-κN 3)oxido­vanadium(IV)

The title mixed-ligand oxidovanadium(IV) compound, [VO(C5H7O2)2(C8H9N3)], contains a VIV atom in a distorted octahedral coordination, which is typical for such complexes. The vanadyl group and the N-heterocyclic ligand are cis to each other. The coordination bond is located at the endocyclic N atom of the benzimidazole ligand. Intra­molecular hydrogen bonds between the exo-NH2 group H atoms and acetyl­acetonate O atoms stabilize the crystal structure

Effect of metformin on transcriptome and adipokinome of adipocytes of local fat deposts of patients with ischemic heart disease

BACKGROUND: The information available to date on the effect of metformin on the transcriptome and secretory capacity of adipocytes in human adipose tissue (AT) is scarce and contradictory. The study analyzed whether metformin in vitro modulates gene expression and secretion of adiponectin and leptin in the AT of subcutaneous (SAT), epicardial (EAT) and perivascular (PVAT) localization of patients with ischemic artery disease (IHD).AIM: To assess the effect of metformin at various concentrations (1 and 10 mmol / L) on the level of expression of adiponectin and leptin genes and their content in adipocytes of subcutaneous, epicardial and perivascular AT of patients with IHD.MATERIALS AND METHODS: The study included 134 patients with IHD and indications for direct myocardial revascularization by coronary artery bypass grafting (CABG). During the operation, biopsies of SAT, EAT and PVAT were obtained for 3–5 gram, which served as a source of adipocytes. Isolated adipocytes were cultured for 24 hours with and without metformin (1 and 10 mmol / L). After a day of incubation, the expression of the ADIPOQ and LEP genes and the level of secretion of adiponectin and leptin in the culture medium of adipocytes were determined. Statistical processing was performed using the GraphPad Prism 6 software package (GraphPad Software, La Jolla, CA, USA) and Statistica software, 6.1 (Dell Software, Inc., Round Rock, TX, USA).RESULTS: The adipocytes of the EAT and PVAT of patients with IHD were characterized by an imbalance in the adipokine system, manifested by a low level of ADIPOQ expression and a high LEP expression in comparison with adipocytes of the SAT. Metformin increased the level of ADIPOQ expression and its secretion by adipocytes regardless of their location, while a low concentration (1 mmol / L) in adipocytes of EAT had a stronger effect compared to 10 mmol / L. Metformin had a multidirectional effect on the level of leptin in adipocytes, which depended on their localization: both in low (1 mmol / L) and high concentrations (10 mmol / L), the drug reduced the level of LEP expression and protein secretion in the culture medium of adipocytes of the SAT. EAT had no significant effect on adipocytes. In PVAT, metformin increased the expression and secretion of leptin regardless of concentration.CONCLUSION: Metformin has a direct effect on adipocytes in SAT, EAT, and PVAT and is able to modulate their activity, which is a promising strategy for maintaining the balance of adipokines in AT, especially epicardial and perivascular localization

Modelling of the effect of ELMs on fuel retention at the bulk W divertor of JET

Effect of ELMs on fuel retention at the bulk W target of JET ITER-Like Wall was studied with multi-scale calculations. Plasma input parameters were taken from ELMy H-mode plasma experiment. The energetic intra-ELM fuel particles get implanted and create near-surface defects up to depths of few tens of nm, which act as the main fuel trapping sites during ELMs. Clustering of implantation-induced vacancies were found to take place. The incoming flux of inter-ELM plasma particles increases the different filling levels of trapped fuel in defects. The temperature increase of the W target during the pulse increases the fuel detrapping rate. The inter-ELM fuel particle flux refills the partially emptied trapping sites and fills new sites. This leads to a competing effect on the retention and release rates of the implanted particles. At high temperatures the main retention appeared in larger vacancy clusters due to increased clustering rate

Determination of tungsten sources in the JET-ILW divertor by spectroscopic imaging in the presence of a strong plasma continuum

The identification of the sources of atomic tungsten and the measurement of their radiation distribution in front of all plasma-facing components has been performed in JET with the help of two digital cameras with the same two-dimensional view, equipped with interference filters of different bandwidths centred on theW I (400.88 nm) emission line. A new algorithm for the subtraction of the continuum radiation was successfully developed and is now used to evaluate the W erosion even in the inner divertor region where the strong recombination emission is dominating over the tungsten emission. Analysis of W sputtering and W redistribution in the divertor by video imaging spectroscopy with high spatial resolution for three different magnetic configurations was performed. A strong variation of the emission of the neutral tungsten in toroidal direction and corresponding W erosion has been observed. It correlates strongly with the wetted area with a maximal W erosion at the edge of the divertor tile

The effect of beryllium oxide on retention in JET ITER-like wall tiles

Preliminary results investigating the microstructure, bonding and effect of beryllium oxide formation on retention in the JET ITER-like wall beryllium tiles, are presented. The tiles have been investigated by several techniques: Scanning Electron Microscopy (SEM) equipped with Energy Dispersive X-ray (EDX), Transmission Electron microscopy (TEM) equipped with EDX and Electron Energy Loss Spectroscopy (EELS), Raman Spectroscopy and Thermal Desorption Spectroscopy (TDS). This paper focuses on results from melted materials of the dump plate tiles in JET. From our results and the literature, it is concluded, beryllium can form micron deep oxide islands contrary to the nanometric oxides predicted under vacuum conditions. The deepest oxides analyzed were up to 2-micron thicknesses. The beryllium Deuteroxide (BeOxDy) bond was found with Raman Spectroscopy. Application of EELS confirmed the oxide presence and stoichiometry. Literature suggests these oxides form at temperatures greater than 700 °C where self-diffusion of beryllium ions through the surface oxide layer can occur. Further oxidation is made possible between oxygen plasma impurities and the beryllium ions now present at the wall surface. Under Ultra High Vacuum (UHV) nanometric Beryllium oxide layers are formed and passivate at room temperature. After continual cyclic heating (to the point of melt formation) in the presence of oxygen impurities from the plasma, oxide growth to the levels seen experimentally (approximately two microns) is proposed. This retention mechanism is not considered to contribute dramatically to overall retention in JET, due to low levels of melt formation. However, this mechanism, thought the result of operation environment and melt formation, could be of wider concern to ITER, dependent on wall temperatures

Improved ERO modelling of beryllium erosion at ITER upper first wall panel using JET-ILW and PISCES-B experience

ERO is a 3D Monte-Carlo impurity transport and plasma-surface interaction code. In 2011 it was applied for the ITER first wall (FW) life time predictions [1] (critical blanket module BM11). After that the same code was significantly improved during its application to existing fusion-relevant plasma devices: the tokamak JET equipped with an ITER-like wall and linear plasma device PISCES-B. This has allowed testing the sputtering data for beryllium (Be) and showing that the “ERO-min” fit based on the large (50%) deuterium (D) surface content is well suitable for plasma-wetted areas (D plasma). The improved procedure for calculating of the effective sputtering yields for each location along the plasma-facing surface using the recently developed semi-analytical sheath approach was validated. The re-evaluation of the effective yields for BM11 following the similar revisit of the JET data has indicated significant increase of erosion and motivated the current re-visit of ERO simulations

Beryllium global erosion and deposition at JET-ILW simulated with ERO2.0

The recently developed Monte-Carlo code ERO2.0 is applied to the modelling of limited and diverted discharges at JET with the ITER-like wall (ILW). The global beryllium (Be) erosion and deposition is simulated and compared to experimental results from passive spectroscopy. For the limiter configuration, it is demonstrated that Be self-sputtering is an important contributor (at least 35%) to the Be erosion. Taking this contribution into account, the ERO2.0 modelling confirms previous evidence that high deuterium (D) surface concentrations of up to ∼50% atomic fraction provide a reasonable estimate of Be erosion in plasma-wetted areas. For the divertor configuration, it is shown that drifts can have a high impact on the scrape-off layer plasma flows, which in turn affect global Be transport by entrainment and lead to increased migration into the inner divertor. The modelling of the effective erosion yield for different operational phases (ohmic, L- and H-mode) agrees with experimental values within a factor of two, and confirms that the effective erosion yield decreases with increasing heating power and confinement