Speaker
InSun Park
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/P1.4008.pdf
Analysis of supersonic plasma flow under the influence of impurity with
gridded-bias in DiPS-2
I.S. Park1, I.J. Kang1, M.-K Bae1, S.H. Lee1, S.J. Jeong1, K.-S Chung1
1
Department of Electrical Engineering, Hanyang University, Seoul, South of Korea
Plasma flow has been an important factor to understand the formation of presheath and
sheath in edge plasma region in term of transition from the subsonic to the supersonic by
satisfying of Bohm criterion [1]. However, this plasma flow would be influenced by dusts and
vapor which were generated by high transient heat loads such as edge localized modes (ELMs)
and plasma-wall interaction in plasma edge. These dusts and vapor have slower velocity than
plasma flow [2], which generates the necessing of analysing plasma flow with impurities. We
generated helium plasma in a linear machine, called Divertor Plasma Simulator – 2 (DiPS - 2),
which generates plasma using LaB6. DiPS – 2 has the following specification and plasma
parameter : B-field = 1 - 3 kG, working pressure ~ 0.1 mTorr, Idis = 1 – 50A, ne ~ 1010 - 1011
cm-3, Te ~ 1 - 25 eV for He plasmas). Plasma flow velocity was measured according to injecting
impurities (Dust, Ar and N2) in helium background plasmas. Ions were accelerated by grid
system (from -100 V to 0 V) in order to generate supersonic plasma. Plasma flow velocity was
analysed using various kinetic model and fluid model. A kinetic model is to be applied to
analyze the experimental results.
References:
[1] Ph Ghendrih et al, Plasma Phys. Control. Fusion 53 (2011) 054019.
[2] A.A. Shoshin et al, Fusion Eng. Des. 114 (2017) 157.
