Recent researches on dust in EAST and HT-7 tokamaks

Recently, the formation during plasma, distribution and basic characteristics of dust, such as morphology, size, composition and retention of hydrogen isotopes, were investigated on EAST and HT-7 superconducting tokamaks. It was found that dust in the two devices had similar characteristics. It was also found that plasma parameters, displacement and configuration were main factors for the dust production. Hot spots produced during long pulse were also an important reason for the production of lots of dust particles. A dust capture experiment using SiO₂ aerogel probe showed hypervelocity dust particles would exist in HT-7, i.e. ^vd>1km/s.