Acceleration of a dust particle in the SOL （scrape-off layer）/divertor plasma of HL- 2A with a single-null configuration is studied. A simplest model of the dust dynamics is applied, namely spherical shape of a dust...Acceleration of a dust particle in the SOL （scrape-off layer）/divertor plasma of HL- 2A with a single-null configuration is studied. A simplest model of the dust dynamics is applied, namely spherical shape of a dust, ion drag force due to Coulomb scattering as a dominant force, and spontaneous charging of a dust particle to the equilibrium charge. In the outer region near the plasma-facing wall the poloidal plasma flow pushes the dust particle to the divertor plates. It is clarified that the dust particle with a radius of 1 μm from the top of the SOL/divertor region is accelerated up to around 100 m/s at the divertor plates along the poloidal direction .展开更多
Results from simulations of plasma and neutrals under conditions predictively characterizing the detached plasma regime in the linear machine MAGNUM-PSI are presented. The relaxation of the vibrationally excited hydro...Results from simulations of plasma and neutrals under conditions predictively characterizing the detached plasma regime in the linear machine MAGNUM-PSI are presented. The relaxation of the vibrationally excited hydrogen molecules is investigated in order to establish a relation between their relaxation and dwell times, and the role of the varions mechanisms of the molecular vibrational kinetics. Tile results obtained show that the individual vibrational states have to be inclllded in the transport code for neutrals as distinct species, since the relaxation time of tile vibrational states is sufficiently longer than the typical dwell time of hydrogen molecules in the detached plasma region. The parameters of plasma and neutrals are affected by the transport of the vibrationally excited hydrogen lnolecnles. Furthermore. the rate of molecular reconlbination is overestimated by a factor of - 5 provided that the transport of ilydrogen molecules only in their ground vibrational state is considered. The role of the various processes of vibrational kinetics is studied. The vibrational excitation through singlet electronic states ires a strong influence on the molecular densities for levels with vibrational quantum numbers v≥ 5. Vibration-vibration （V-V） collisions between vibrationally excited hydrogen molecules and vibration-translation （V-T） collisions between vibrationally excited hydrogen molecules and ground state molecules and atoms are of nlinor importance in MAGNUM-PSI.展开更多
基金the JSPS-CAS Core-University Program in the field of Plasma and Nuclear Fusiona Grant-in-Aid for scientific research from Ministry of Education,Science and Culture of Japan (No.19055005)the program of the Formation of the International Joint Research Base Network in the National Institute for Fusion Science.
文摘Acceleration of a dust particle in the SOL （scrape-off layer）/divertor plasma of HL- 2A with a single-null configuration is studied. A simplest model of the dust dynamics is applied, namely spherical shape of a dust, ion drag force due to Coulomb scattering as a dominant force, and spontaneous charging of a dust particle to the equilibrium charge. In the outer region near the plasma-facing wall the poloidal plasma flow pushes the dust particle to the divertor plates. It is clarified that the dust particle with a radius of 1 μm from the top of the SOL/divertor region is accelerated up to around 100 m/s at the divertor plates along the poloidal direction .
基金the European Communities under the contract of Association between EURATOM/FOM
文摘Results from simulations of plasma and neutrals under conditions predictively characterizing the detached plasma regime in the linear machine MAGNUM-PSI are presented. The relaxation of the vibrationally excited hydrogen molecules is investigated in order to establish a relation between their relaxation and dwell times, and the role of the varions mechanisms of the molecular vibrational kinetics. Tile results obtained show that the individual vibrational states have to be inclllded in the transport code for neutrals as distinct species, since the relaxation time of tile vibrational states is sufficiently longer than the typical dwell time of hydrogen molecules in the detached plasma region. The parameters of plasma and neutrals are affected by the transport of the vibrationally excited hydrogen lnolecnles. Furthermore. the rate of molecular reconlbination is overestimated by a factor of - 5 provided that the transport of ilydrogen molecules only in their ground vibrational state is considered. The role of the various processes of vibrational kinetics is studied. The vibrational excitation through singlet electronic states ires a strong influence on the molecular densities for levels with vibrational quantum numbers v≥ 5. Vibration-vibration （V-V） collisions between vibrationally excited hydrogen molecules and vibration-translation （V-T） collisions between vibrationally excited hydrogen molecules and ground state molecules and atoms are of nlinor importance in MAGNUM-PSI.
