Capture by aerogel—characterization of mobile dust in tokamak scrape-off layer plasmas

Abstract

The aim of this letter is to demonstrate the feasibility and potential of the novel in situ dust diagnostic method—capture by aerogel targets. Aerogel, a highly porous material with a density of a few tens of kg m −3 , allows capturing of dust particles present during the discharge without destroying them. The first exposures in the TEXTOR scrape-off layer plasma showed that such targets are able to capture both slow and fast particles with sizes in the range from submicrometre to ∼100 µm. The technique provides information on dust velocity and size distribution as well as dust flux estimates. The composition and texture of the captured dust can also be studied in detail to shed light on dust formation processes.