Speaker
Dr
Andrey Shoshin
(Budker INP SB RAS)
Description
Results from different facilities for PSI studies are compared and their relevance to each other and conditions of ITER transient events are discussed.
For PSI studies at the GOL-3 we can use different e-beam sources and can vary energy loads to the targets form 0.3 to 30 MJ/m$^2$. For PSI studies also used tokamaks, linear plasma machines including QSPA (quasi-stationary plasma accelerators), e-beams and lasers.
At QSPA the vapor shield effect limits the power that is delivered to the surface at the level of 4.5 GW/m$^2$. This effect is determined by relative low energy of ions, which is about one order of magnitude lower than ion energy expected in ITER (1÷2.5 keV during ELM). This plasma pressure in QSPA experiments is at least one order of magnitude stronger than that expected in ITER and can result in different mechanism of droplet ejection in simulations.
At energy loads corresponding to ITER transient events (ELMs, disruptions, etc.) only macroscopic erosion mechanisms are important. It is cracking, droplet formation and macroscopic mass losses of the target. Cracking occurs after irradiations during cooling stage or by plastic deformation at the peak temperature. So details of plasma stream parameters are not important, only target temperature play role. Macroscopic mass losses strongly correspond with melting of the thin surface layer and key role for melting play heat loads.
Heat flux plays key role to the targets surface erosion.
Primary author
Dr
Andrey Shoshin
(Budker INP SB RAS)
Co-authors
Prof.
Aleksandr Burdakov
(Budker INP SB RAS)
Dr
Aleksey Arakcheev
(Budker INP SB RAS)
Mr
Alexander Vasilyev
(Budker INP SB RAS, Novosibirsk State University)
Mr
Alexandr Kasatov
(Budker INP SB RAS)
Dr
Ivan Ivanov
(Budker INP SB RAS)
Dr
Leonid Vyacheslavov
(Budker INP SB RAS)
Dr
Sergey Polosatkin
(Budker INP SB RAS)
Dr
Vladimir Postupaev
(Budker INP SB RAS)
