Erosion of the ITER main chamber first wall (FW) beryllium (Be) armour is expected to affect the lifetime of FW panel, dust formation, and release of Be impurities potentially leading to enhanced sputtering of the W divertor and tritium retention due to co-deposition. The ITER FW panels are shaped to protect leading edges and misalignments, which leads to magnetically shadowed regions, where...
Collisional radiative (CR) models represent the most versatile type of population models used for determining plasma parameters or for predicting for known plasma parameters the plasma behavior. In plasmas used in fusion research the particle temperatures and densities can cover a wide range. Typically, the edge plasma of fusion devices is much cooler than the core plasma, resulting in the...
Tungsten used as a plasma-facing material for divertor in fusion devices is sputtered and transported into plasmas. The tungsten behaviors in divertor, edge, and core plasmas should be examined by spectroscopic methods, and the spectroscopic models and atomic data for a wide charge state range of tungsten ions are required to analyze tungsten spectra. Many studies have been done on tungsten...
Fulcher Bands of the hydrogenic molecular spectra are complex triplet bands in the visible region (590-630 nm). The electronic transition is identified as d (3p$^3$Π$_u$) at approximately 14 eV level energy to a (2s$^3$Σ$^+_g$) at 12 eV, but this is not the sole electronic transition in this region, as the g→c (3d $^3$Σ$^+_g$ → 2p$^3$Π$_u$) transition is present in this wavelength region as...
A summary on the numerical assessment of detailed distribution of neutral particles impinging specific diagnostic surfaces in ITER (i.e. mirrors on upper-outer limiter or midplane) was given. Demonstrated are the EIRENE post-processing of ITER SOLPS4.3 simulations including an extension of plasma on an artificial grids up to first wall (c.f. based on previous simulations by A. Khan NME 2019)....
Measurements in JET ITER-like Wall low-confinement mode plasmas showed that the scrape-off layer at the low-field side midplane was $30 \%$ broader and the low-field side divertor plasma a factor of $2-3$ more strongly detached in pure-tritium than in pure-protium plasmas for otherwise similar core plasma conditions. The conditions in pure-deuterium and in a $40 \% - 60 \%$ deuterium-tritium...
The need for quantitative spectroscopy of molecular hydrogen has experienced substantial demand, leading to the accumulation of diverse elementary-processes data encompassing radiative transitions, electron-impact transitions, and predissociations. In this study, we attempt an experimental validation of this dataset by comparing the vibronic populations across multiple molecular hydrogen...
Kinetic sputtering of materials during bombardment with energetic particles is a well understood process for the case of perfectly flat surfaces. Both analytical models and numerical simulation codes have been established in the last decades showing good agreement for quantities accessible by experiments like the sputtering yield. Still, for many applications, e.g., plasma-facing materials in...
Molecular Dynamics simulations is a powerful tool in investigating the effects on surfaces under various conditions. It is especially effective for studying the interaction between energetic particles and surfaces. Due to relevancy to fusion, tungsten surfaces have been studied under various conditions. Both pristine surfaces and atomistically rough surfaces have been studied under irradiation...
In this talk will be presented our last results on electron-H$_2$ and -D$_2$ collisions. We will focus in particular on the vibrational-excitation, dissociative-attachment, dissociative-recombination and dissociative-excitation processes rotationally and vibrationally resolved.
Upper and lower graphite divertors in EAST tokamak were replaced by tungsten divertors in 2014 and 2021, respectively, to improve plasma performance in long pulse discharges and accumulate knowledges on the tungsten divertor operation. Studies on the tungsten behavior in edge and core plasmas are then crucially important for improving the plasma performance. For the purpose four...
Thailand is one of the countries that recognizes the importance of fusion technology and has a national plan for its implementation. The Thailand Institute of Nuclear Technology (TINT) has been engaged in the development of a tokamak device known as Thailand Tokamak-1 (TT-1) since 2015. This device is derived from the HT-6M, a previous tokamak device developed by the Chinese Academy of Science...
W generation and transport study represents one of the hottest topics for next generation tokamaks with full metal plasma-facing components [1-4]. The existing W sputtering models are based on low density plasma sheath approximation [5-7], which might be not applicable for high density divertor plasmas expected in future machines, e.g. like ITER and DEMO.
In the given presentation we...
Sputtering is one of the fundamental processes at plasma-facing components in fusion experiments as the lifetime of the components strongly depends on the sputtering rates. Therefore, it is of paramount importance to understand the processes underlying the sputtering, including the energy, angular and atomic level distribution functions of the sputtered tungsten (W). These distribution...
Tungsten is being considered as a plasma-facing material in magnetically confined fusion devices, such as ITER. Electron collision ionization is a dominant atomic process in fusion plasma which determines the ionization balance of the non-local thermal equilibrium plasmas. Despite great effort have been pain the experimental measurements and theoretical calculations, however, the effect of...
The reflection and sputtering properties of surfaces under energetic particle impact have been studied theoretically and experimentally since several decades and for many systems (especially planar, mono-elemental and amorphous target-systems) a comprehensive level of knowledge does exist. The situation is considerably less satisfying once the target system exhibits more complex features....
Dedicated computer codes are used to address the physics of plasma-wall interaction and related issues of wall lifetime and long-term tritium retention in fusion devices. The Monte-Carlo code ERO2.0 is such an example, which allows numerical modeling of realistic three-dimensional device geometries based on its massive parallelization [1]. In addition to (net) erosion and re-deposition maps on...
Introduction to open issues in the new ITER baseline with a W wall for Q = 10 operation that require experimental assessment.
The present study has determined excitation energy of the 127 states of the transmutation of tungsten atoms He-like-(Hf, Ta, Re and Os). In this work, we use the ab initio MCDHF and MBPT methods implemented in GRASP2018 and FAC codes, respectively. We extend the calculation for n = 8 to improve the precision of the atomic data used in line identification, plasma modeling and diagnostics of...
The Pakistan Spherical Tokamak (PST) is a small-sized spherical tokamak currently in the design and development phase. A double null divertor configuration is being considered for the steady-state operation of the PST. Two different divertor materials concepts are under consideration for the PST and other devices in the future. The interaction between plasma and tungsten surfaces leads to...
• Egyptian Atomic Energy Authority – Plasma Focus device 1 (EAEA-PF1) was successfully redesigned in terms of its electrode system material and dimensions, insulator shape and the energy storage bank to investigate the best plasma focus action.
• A simple-to-perform technique was applied to investigate the distribution of the azimuthal magnetic field induction and the induced magnetic force...
Hydrogen glow discharge cleaning (H-GDC) is a routine conditioning procedure for the present tokamaks and the future fusion machines, including the ITER. Due to the low energy of hydrogen ions in glow discharge plasmas, the probability of any considerable damage to the plasma facing components was mainly ignored among researchers in the field. In this work, Tungsten and Molybdenum, as the...
