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
Using the trans-neut module of the BOUT＋＋ code, we study how the fueling penetration depth of supersonic molecular beam injection（SMBI） is affected by plasma density and temperature profiles. The plasma densities ...Using the trans-neut module of the BOUT＋＋ code, we study how the fueling penetration depth of supersonic molecular beam injection（SMBI） is affected by plasma density and temperature profiles. The plasma densities and temperatures in L-mode are initialized to be a set of linear profiles with different core plasma densities and temperatures. The plasma profiles are relaxed to a set of steady states with different core plasma densities or temperatures. For a fixed gradient, the steady profiles are characterized by the core plasma density and temperature. The SMBI is investigated based on the final steady profiles with different core plasma densities or temperatures. The simulated results suggest that the SMB injection will be blocked by dense core plasma and high-temperature plasma. Once the core plasma density is set to be N（i0）= 1.4N0（N0= 1 × 10^19m^-3） it produces a deeper penetration depth. When N（i0） is increased from 1.4N0 to 3.9N0 at intervals of 0.8N0, keeping a constant core temperature of T（e0）= 725 eV at the radial position of ψ = 0.65, the penetration depth gradually decreases. Meanwhile, when the density is fixed at N（i0）= 1.4N0 and the core plasma temperature T（e0） is set to 365 eV,the penetration depth increases. The penetration depth decreases as T（e0） is increased from 365 eV to 2759 eV. Sufficiently large N（i0） or T（e0） causes most of the injected molecules to stay in the scrape-off-layer（SOL） region, lowering the fueling efficiency.展开更多
Loss-cone instabilities are studied for linear fusion devices. The gyro-kinetic equation for such a configuration is rigorously constructed in terms of action-angle variables by making use of canonical transformation....Loss-cone instabilities are studied for linear fusion devices. The gyro-kinetic equation for such a configuration is rigorously constructed in terms of action-angle variables by making use of canonical transformation. The dispersion relation, including for the first time, finite bounce frequency is obtained and numerically solved. The loss-cone modes are found near ion-cyclotron frequency. The growth rates are greatly reduced and approaching zero with increasing beta value. The results suggest that loss-cone instabilities are unlikely to be threatening to linear fusion devices since a new longitudinal invariant is found and gives a constraint which helps confinement.展开更多
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supported by the National Natural Science Foundation for Young Scientists of China(Grant No.11605143)the Undergraduate Training Programs for Innovation and Entrepreneurship of Sichuan Province,China(Grant No.05020732)+4 种基金the National Natural Science Foundation of China(Grant No.11575055)the Fund from the Department of Education in Sichuan Province of China(Grant No.15ZB0129)the China National Magnetic Confinement Fusion Science Program(Grant No.2013GB107001)the National ITER Program of China(Contract No.2014GB113000)the Funds of the Youth Innovation Team of Science and Technology in Sichuan Province of China(Grant No.2014TD0023)
文摘Using the trans-neut module of the BOUT＋＋ code, we study how the fueling penetration depth of supersonic molecular beam injection（SMBI） is affected by plasma density and temperature profiles. The plasma densities and temperatures in L-mode are initialized to be a set of linear profiles with different core plasma densities and temperatures. The plasma profiles are relaxed to a set of steady states with different core plasma densities or temperatures. For a fixed gradient, the steady profiles are characterized by the core plasma density and temperature. The SMBI is investigated based on the final steady profiles with different core plasma densities or temperatures. The simulated results suggest that the SMB injection will be blocked by dense core plasma and high-temperature plasma. Once the core plasma density is set to be N（i0）= 1.4N0（N0= 1 × 10^19m^-3） it produces a deeper penetration depth. When N（i0） is increased from 1.4N0 to 3.9N0 at intervals of 0.8N0, keeping a constant core temperature of T（e0）= 725 eV at the radial position of ψ = 0.65, the penetration depth gradually decreases. Meanwhile, when the density is fixed at N（i0）= 1.4N0 and the core plasma temperature T（e0） is set to 365 eV,the penetration depth increases. The penetration depth decreases as T（e0） is increased from 365 eV to 2759 eV. Sufficiently large N（i0） or T（e0） causes most of the injected molecules to stay in the scrape-off-layer（SOL） region, lowering the fueling efficiency.
基金supported by the Natural Science Foundation for Young Scientists of China (No. 11605143)National Natural Science Foundation of China (Nos. 11575055,11261140327,11005035,11205053)+3 种基金the project,Plasma Confinement in the Advanced Magnetic Mirror (WX-2015-01-01)the Open Research Subject of the Key Laboratory of Advanced Computation in Xihua University (Nos. szjj2017-011 and szjj2017-012)the Young Scholarship Plan of Xihua University (No. 0220170201)the National Key Research and Development Program of China (No. 2017YFE0300405)
文摘Loss-cone instabilities are studied for linear fusion devices. The gyro-kinetic equation for such a configuration is rigorously constructed in terms of action-angle variables by making use of canonical transformation. The dispersion relation, including for the first time, finite bounce frequency is obtained and numerically solved. The loss-cone modes are found near ion-cyclotron frequency. The growth rates are greatly reduced and approaching zero with increasing beta value. The results suggest that loss-cone instabilities are unlikely to be threatening to linear fusion devices since a new longitudinal invariant is found and gives a constraint which helps confinement.
