Student: Šimon Vrba
Školitel: David Tskhakaya, Ph.D. (ÚFP AV ČR)
Konzultant: Doc. RNDr. Jiří Pavlů, Ph.D.
Stav práce: volná
Anotace:
Thermonuclear fusion reactors are often assumed to be the main energy source in the future. Although the main work principles of such reactors are well known, there are still several problems requiring further scientific study. Among the main testing fusion plasma facilities are the magnetic confinement fusion devices - tokamaks and stellarators; the largest international tokamak, ITER, will be built in France [1]. One of the problems to be solved in future tokamaks and stellarators is the plasma exhaust: when hot plasma of 100 million degrees Celsius must be sufficiently cooled down (at least to ~10 thousand degrees) before it reaches the machine chamber wall. Scientific study of this process is an extremely challenging task, which is usually performed by numerical modelling of fluid plasma and kinetic neutral transport codes [2].
Our recent study indicated that number of kinetic effects, which might not play a crucial role in our day fusion plasma edge, might be essential in next generation machines like ITER [3]. Among such effects are: heat loads to the divertor plates via non-Maxwellian hot electron fractions, ELM heat loads to the ITER divertor plates and related W sputtering from the divertor surface.
The aim of the proposed PhD work is to study and apply the fully kinetic PIC + MC (Particle in Cell Monte Carlo) code, BIT1, for nonlinear transport of plasma, impurity and neutral particles, and their interaction with the divertor plates during the inter-ELM and the ELMy phases in the ITER Scrape-off Layer (SOL). BIT1 has several unique features enabling near ab-initio modeling of nonlinear processes in the plasma edge: it can resolve the smallest time and space scales and still simulate large systems, such as the tokamak SOL and can track very slow and fast particles with high accuracy, Vmax/Vmin > 103 and so on.
The primary target of the PhD work will be the investigation of the ELM parallel transport in the SOL, the corresponding plasma-wall interaction processes and estimation of the erosion rates of the divertor surface made of tungsten (W). The study will be performed in few steps, with increasing complexity and realism of the SOL model. The obtained results will be disseminated via publications in leading fusion plasma related journals and presentations at international conferences, as well as will be directly provided to ITER organization. We expect them to be widely used within fusion plasma community to estimate W transport and concentration in the core plasma to avoid possible contamination, as well as to avoid unacceptably high erosion rates of divertor plates in ITER.
References:
[1] https://www.iter.org/
[2] P. Stangeby, The Plasma Boundary of Magnetic Fusion Devices, ed S Laurenson (Bristol: Institute of Physics Publishing), 2000
[3] D. Tskhakaya, Plasma Phys. Control. Fusion, 59, (2017) 114001 (19pp)
Journal papers upon recommendation of supervisor