In tokamak plasma fueling, supersonic molecule beam injection(SMBI) with a higher fueling efficiency and a deeper penetration depth than the traditional gas puffing method has been developed and widely applied to many...In tokamak plasma fueling, supersonic molecule beam injection(SMBI) with a higher fueling efficiency and a deeper penetration depth than the traditional gas puffing method has been developed and widely applied to many tokamak devices.It is crucial to study the transport dynamics of SMBI to improve its fueling efficiency, especially in the high confinement regime. A new one-dimensional(1D) code of TPSMBI has also been developed recently based on a six-field SMBI model in cylindrical coordinate. It couples plasma density and heat radial transport equations together with neutral density transport equations for both molecules and atoms and momentum radial transport equations for molecules. The dominant particle collisional interactions between plasmas and neutrals, such as molecule dissociation, atom ionization and charge-exchange effects, are included in the model. The code is verified to be correct with analytical solutions and also benchmarked well with the trans-neut module of BOUT++ code. Time-dependent radial transport dynamics and mean profile evolution are studied during SMBI with the TPSMBI code in both slab and cylindrical coordinates. Along the SMBI path, plasma density increases due to particle fuelling, while plasma temperature decreases due to heat cooling. Being different from slab coordinate, the curvature effect leads to larger front densities of molecule and atom during SMBI in cylindrical coordinate simulation.展开更多
To study helium(He)supersonic molecular beam injection(SMBI)into H-mode tokamak plasma,a simplified multicomponent-plasma model under the assumption of quasi-neutral condition is developed and implemented in the frame...To study helium(He)supersonic molecular beam injection(SMBI)into H-mode tokamak plasma,a simplified multicomponent-plasma model under the assumption of quasi-neutral condition is developed and implemented in the frame of BOUT++.The simulation results show that He species propagate inwards after He SMBI,and are deposited at the bottom of the pedestal due to intensive ionization and weak spreading speed.It is found that almost all injected helium particles strip off all the bounded electrons.He species interact intensively with background plasma along the injection path during He SMBI,making deuterium ion density profile drop at the He-deposited location and resulting in a large electron temperature decreasing,but deuterium ion temperature decreasing a little at the top of the pedestal.展开更多
In this paper, we describe the behavior of impurity transport in the HL-2A electron cyclotron resonance heating （ECRH） L-mode plasma. The neon as a trace impurity is injected by the supersonic molecular beam injecti...In this paper, we describe the behavior of impurity transport in the HL-2A electron cyclotron resonance heating （ECRH） L-mode plasma. The neon as a trace impurity is injected by the supersonic molecular beam injection （SMBI） technique, which is used for the first time to study the impurity transport in HL-2A. The progression of neon ions is monitored by the soft X-ray camera and bolometer arrays with good temporal and spatial resolutions. The convection and diffusion process of the neon ions are investigated with the one-dimensional impurity transport code STRAHL. The results show that the diffusion coefficient D of neon ions is a factor of four larger than the neoclassical value in the central region. The value of D is larger in the outer region of the plasma （ρ 〉 0.6） than in the central region of the plasma （ρ 〈 0.6）. The convective velocity directs inwards with a value of ～-1.0 m/s in the Ohmic discharge, but it reverses to direct outwards with a value of ～ 8.0 m/s in the outer region of the plasma when ECRH is applied. The result indicates that the impurity transport is strongly enhanced with ECRH.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.11575055,11375053,and 11475219)the National Magnetic Confinement Fusion Science Program of China(Grant Nos.2013GB111005,2014GB108004,and 2015GB110001)
文摘In tokamak plasma fueling, supersonic molecule beam injection(SMBI) with a higher fueling efficiency and a deeper penetration depth than the traditional gas puffing method has been developed and widely applied to many tokamak devices.It is crucial to study the transport dynamics of SMBI to improve its fueling efficiency, especially in the high confinement regime. A new one-dimensional(1D) code of TPSMBI has also been developed recently based on a six-field SMBI model in cylindrical coordinate. It couples plasma density and heat radial transport equations together with neutral density transport equations for both molecules and atoms and momentum radial transport equations for molecules. The dominant particle collisional interactions between plasmas and neutrals, such as molecule dissociation, atom ionization and charge-exchange effects, are included in the model. The code is verified to be correct with analytical solutions and also benchmarked well with the trans-neut module of BOUT++ code. Time-dependent radial transport dynamics and mean profile evolution are studied during SMBI with the TPSMBI code in both slab and cylindrical coordinates. Along the SMBI path, plasma density increases due to particle fuelling, while plasma temperature decreases due to heat cooling. Being different from slab coordinate, the curvature effect leads to larger front densities of molecule and atom during SMBI in cylindrical coordinate simulation.
基金Chunhui Program of the Ministry of Education of China(Grant No.Z2017091)the Sichuan Provincial Science Foundation for Distinguished Young Leaders of Disciplines in Science and Technology,China(Grant Nos.2019JDJQ0051 and 2019JDJQ0050)+2 种基金the National Natural Science Foundation of China(Grant Nos.11575055 and 11605143)the Fund for Young Scientists of China,the Open Research Subjects of the Key Laboratory of Advanced Computation in Xihua University,China(Grant Nos.szjj2017-011 and szjj2017-012)the Young Scholarship Plan of Xihua University,China(Grant No.0220170201).
文摘To study helium(He)supersonic molecular beam injection(SMBI)into H-mode tokamak plasma,a simplified multicomponent-plasma model under the assumption of quasi-neutral condition is developed and implemented in the frame of BOUT++.The simulation results show that He species propagate inwards after He SMBI,and are deposited at the bottom of the pedestal due to intensive ionization and weak spreading speed.It is found that almost all injected helium particles strip off all the bounded electrons.He species interact intensively with background plasma along the injection path during He SMBI,making deuterium ion density profile drop at the He-deposited location and resulting in a large electron temperature decreasing,but deuterium ion temperature decreasing a little at the top of the pedestal.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.10975048,11175061,and 10975049)
文摘In this paper, we describe the behavior of impurity transport in the HL-2A electron cyclotron resonance heating （ECRH） L-mode plasma. The neon as a trace impurity is injected by the supersonic molecular beam injection （SMBI） technique, which is used for the first time to study the impurity transport in HL-2A. The progression of neon ions is monitored by the soft X-ray camera and bolometer arrays with good temporal and spatial resolutions. The convection and diffusion process of the neon ions are investigated with the one-dimensional impurity transport code STRAHL. The results show that the diffusion coefficient D of neon ions is a factor of four larger than the neoclassical value in the central region. The value of D is larger in the outer region of the plasma （ρ 〉 0.6） than in the central region of the plasma （ρ 〈 0.6）. The convective velocity directs inwards with a value of ～-1.0 m/s in the Ohmic discharge, but it reverses to direct outwards with a value of ～ 8.0 m/s in the outer region of the plasma when ECRH is applied. The result indicates that the impurity transport is strongly enhanced with ECRH.
