Thermal behaviour of redeposited layer under high heat flux exposure

Theoretical simulation of thermal behavior in transient heat loads testing of plasma-facing materials

“…On the other hand, theoretical analyses based on the analytical models [17][18][19][20][21] or using finite element methods (FEM) [22][23][24] have also been performed to understand the thermal behavior of PFMs under HHF testing with plasma, electrons and ions recently. Furthermore, Rodig and Linke et al [4][5][6] have made great efforts to experimentally compare different HHF testing facilities with electron/ion beams under steady state conditions, where they have shown that the testing of actively cooled samples 0920-3796/$ -see front matter © 2011 Elsevier B.V. All rights reserved.…”

Plasma wall interaction during ELMs in JET

“…The temperature increase is more pronounced on the inner wall due to the combined effect of the ELM energy deposited and the codeposited layer, which is mainly located on the inner divertor in JET (in normal magnetic field configuration) [2]. These codeposited layers, with low thermal conductivity induce an offset in temperature during exposure to high heat flux [3]. The location of the ELM interaction with the main chamber may vary from a shot to another one, in particular with the magnetic configuration.…”

Dust in ITER: Diagnostics and removal techniques

“…From the current feedback in existing Tokamaks, deposits and dust have SSAs of the same order of magnitude. Infra red thermography [8] coupled with laser induced breakdown spectroscopy [9] for the deposit thickness calibration, or Speckle interferometry, could be used to obtain a mapping of the deposited areas in the divertor region (including the tile castellations). Because of the specific geometry of the divertor, the observation of the lower vertical targets, leading to glancing incidence for the optical measurements, will have to be carefully addressed.…”

“…This would be required at least when the material configuration is changed but could be needed earlier if the dust inventory under the divertor cassettes is identified as an issue. Liquid [8] or gas blasting could be used to mobilize and collect the dust that could then be evacuated in drains present in two ITER lower ports. In the latter case, the impact on the machine conditioning and the fluid processing need to be addressed.…”