A simulation on HCSB-DEMO （helium-cooled solid breeder, HCSB） edge plasma, by using 2D edge plasma transport code SOLPS5.0, is presented. There is 400 MW heat power crossing CIB （core interface boundary）. The heat...A simulation on HCSB-DEMO （helium-cooled solid breeder, HCSB） edge plasma, by using 2D edge plasma transport code SOLPS5.0, is presented. There is 400 MW heat power crossing CIB （core interface boundary）. The heat flux profiles and peak flux at the divertor targets with different boundary densities axe investigated. It is indicated that the HCSB-DEMO divertor should operate at a proper upstream density in order to avoid a high heat flux at the divertor targets. When the upstream density is 0.63x 102~ m-3, the peak heat flux at the divertor targets will be above 17 MW/m2. The cross-field transport, the power crossing CIB and the power fraction taken by electrons and ions and SOL （scrape-off-layer） thickness are analyzed as unknown parameters. It is shown that the peak flux at the divertor target is very sensitive to these parameters. The simulation results will be used in the divertor design for HCSB-DEMO.展开更多
One of the critical issues to be solved for HL-2M is the power exhaust.Divertor target plate geometry strongly influences the plasma profiles by controlling the neutral recycling pattern,which in turn has a strong eff...One of the critical issues to be solved for HL-2M is the power exhaust.Divertor target plate geometry strongly influences the plasma profiles by controlling the neutral recycling pattern,which in turn has a strong effect on the symmetry and stability of the divertor plasma and finally on the whole edge region.The numerical simulation SOLPS5.0 package is used to design and explore the divertor target plates for HL-2M.We start with the choice of a proper target plate geometry,which has a smaller incidence angle in the permissible space,and then discuss the method of gas puffing to reduce the heat flux density on the target and the effects of gas puffing on the divertor plasma performance.展开更多
The edge transport code SOLPS5.0 is used to model edge plasmas in the experi- mental shots on JT-60U and the profiles of the transverse particle and heat transport coefficients D, Xe and Xi along the outer midplane ar...The edge transport code SOLPS5.0 is used to model edge plasmas in the experi- mental shots on JT-60U and the profiles of the transverse particle and heat transport coefficients D, Xe and Xi along the outer midplane are obtained by fitting the simulational results to the experimental data in L-mode shot 39090 and H-mode shots 37851, 37856. The modelling and fitting results show that within the pedestal region in H-mode shots 37851 and 37856 the radial particle transport coefficient D exhibits a significant drop, but, for L-mode shot 39090, the obvious drop in both D and Xe was not found.展开更多
One of the critical issues to be solved for HL-2M is the power and particle exhaust. Divertor target plate geometry strongly influences the plasma profiles by controlling the neutral recycling pattern, which has in tu...One of the critical issues to be solved for HL-2M is the power and particle exhaust. Divertor target plate geometry strongly influences the plasma profiles by controlling the neutral recycling pattern, which has in turn a strong effect on the symmetry and stability of the divertor plasma and finally on the whole edge region. The numerical simulation software SOLPS5.0 Pack- age is used to design and explore the divertor target plates for HL-2M. We choose two divertor geometries, and assess the heat flux on the target plates and first wall, then further discuss the di- vertor plasma parameters, and how private flux baffling affects both neutral recirculation pattern and pumping efficiency.展开更多
The edge plasma code package SOLPS5.0 is employed to simulate the divertor power footprint widths of the experimental advanced superconducting tokamak （EAST） L-mode and ELM-free H-mode plasmas.The divertor power foo...The edge plasma code package SOLPS5.0 is employed to simulate the divertor power footprint widths of the experimental advanced superconducting tokamak （EAST） L-mode and ELM-free H-mode plasmas.The divertor power footprint widths,which consist of the scrape-off layer （SOL） width λq and heat spreading S,are important physical parameters for edge plasmas.In this work,a plasma current scan is implemented in the simulation to obtain the dependence of the divertor power footprint width on the plasma current Ip.Strong inverse scaling of the SOL width with Ip has been achieved for both L-mode and H-mode plasmas in the forms of λq,L-mode =4.98 × Ip-0.68 and λq,H-mode =1.86 × Ip-1.08.Similar trends have also been demonstrated in the study of heat spreading with SL-mode =1.95 × Ip-0.542 and SH-mode =0.756 × Ip-0.872.In addition,studies on divertor peak heat load and the magnetic flux expansion factor show that both of them are proportional to plasma current.The simulation work here can act as a way to explore the power footprint widths of future tokamak fusion devices such as ITER and the China Fusion Engineering Test Reactor （CFETR）.展开更多
A detailed study of the divertor performance in EAST has been performed for both its double null （DN） and single null （SN） configurations. The results of application of the SOLPS （B2-Eirene） code package to the ...A detailed study of the divertor performance in EAST has been performed for both its double null （DN） and single null （SN） configurations. The results of application of the SOLPS （B2-Eirene） code package to the analysis of the EAST divertor are summarized. In this work, we concentrate on the effects of increased geometrical closure and of magnetic topology variation on the scrape-off layer （SOL） and divertor plasma behavior. The results of numerical predictions for the EAST divertor operational window are also described in this paper. A simple Core-SOL- Divertor （C-S-D） model was applied to investigate the possibility of extending plasma operational space of low hybrid current drive （LHCD） experiments for EAST.展开更多
A comparative study of SN （single null）, DDN （disconnected double-null） and DN （double null） diverters for HCSB-DEMO （helium-cooled solid breeder, HCSB） is reported in this paper by using the 2D edge plasma tr...A comparative study of SN （single null）, DDN （disconnected double-null） and DN （double null） diverters for HCSB-DEMO （helium-cooled solid breeder, HCSB） is reported in this paper by using the 2D edge plasma transport code SOLPS5.0. There is a heat power of 400 MW crossing CIB （core interface boundary）. The peak heat flux at targets with different upstream densities is investigated. It is indicated that the peak heat flux at the outer target with a SN diverter is lower than that at the outer-down target with a DDN diverter under the same upstream density, but is higher than that at the outer target with a DN diverter. The diverter should operate at a proper upstremn density to avoid strong high heat flux at the targets. The peak heat flux at the targets and first wail are sensitive to the SOL （scrape-off-layer） grid thickness. The simulated results wilt provide data for the design of diverter in HCSB-DEMO.展开更多
The effect of poloidal E × B and diamagnetic drifts in edge plasma of Small Size Divertor (SSD) Tokamak is studied with two-dimensional B2SO- LPS-0.5.2D fluid transport code. The simulation results show the follo...The effect of poloidal E × B and diamagnetic drifts in edge plasma of Small Size Divertor (SSD) Tokamak is studied with two-dimensional B2SO- LPS-0.5.2D fluid transport code. The simulation results show the following: 1) For normal toroidal magnetic field, the increasing of core plasma density leads to large divertor asymmetries due to poloidal E × B and diamagnetic drifts. 2) Switching on the E × B and diamagnetic drifts leads to large change in poloidal distribution of radial electric field and induced counter-clockwise circulation (flow) around the x-point. 3) Switching on the E × B and diamagnetic drifts leads to the structure of poloidal distribution of radial electric field is nonmonotonic which responsible for negative spikes. 4) Switching on the E × B and diamagnetic drifts in vicinity of separatrix leads to the structure of poloidal distribution of radial electric field that has viscous layer. 5) Switching on the E × B and diamagnetic drifts results in torque generation. This torque spins up the toroidal rotation. 6) The E × B drift velocity depends on the plasma temperature heating and doesn't depend on plasma density.展开更多
A low density plasma edge of small size divertor tokamak has been modeling by “B2SOLPS0.5.2 D” fluid transport code. The results of modeling are: 1) Formation of the strong “ITB” has detected more reliable with di...A low density plasma edge of small size divertor tokamak has been modeling by “B2SOLPS0.5.2 D” fluid transport code. The results of modeling are: 1) Formation of the strong “ITB” has detected more reliable with discovery that, low density plasma is necessary and important condition for it to form. 2) Reduction of plasma density play significantly role in the formation of the strong ITB as global parameter, possibly through change in the steep density gradient which stabilize “ITG” mode. 3) The radial electric field of small size divertor tokamak plasma edge is plasma density dependence and maximum radial electric field shear is found at low plasma density. 4) In the “NBI” discharge the toroidal (parallel) velocity at low plasma density is co-current and upward direction. 5) The structure of plasma pressure and radial electric field in quiescent H-mode are obtained.展开更多
Asymmetries between the divertor legs of small size divertor (SSD) tokamak plasma edge are noticed to reverse when the direction of toroidal magnetic field is reversed. In the present paper the small size divertor tok...Asymmetries between the divertor legs of small size divertor (SSD) tokamak plasma edge are noticed to reverse when the direction of toroidal magnetic field is reversed. In the present paper the small size divertor tokamak plasma edge under effect of toroidal magnetic field reversal is simulated by B2SOLPS0.5.2D fluid transport code. The simulation demonstrate the following results: 1) Parallel (toroidal) flow flux and Mach number up to 0.6 at higher plasma density reverse with reverse toroidal magnetic direction in the edge plasma of small size divertor tokamak. 2) The radial electric field is toroidal magnetic direction independence in edge plasma of small size divertor tokamak. 3) For normal and reverse toroidal magnetic field, the strong ITB is located between the positions of the maximum and minimum values of the radial electric field shear. 4) Simulation result shows that, the structure of radial electric field at high field side (HFS) and low field side (LFS) is different. This difference result from the change in the parallel flux flows in the scrape off layer (SOL) to plasma core through separatrix. 5) At a region of strong radial electric field shear, a large reduction of poloidal rotation was observed. 6) The poloidal rotation is toroidal magnetic field direction dependence.展开更多
文摘A simulation on HCSB-DEMO （helium-cooled solid breeder, HCSB） edge plasma, by using 2D edge plasma transport code SOLPS5.0, is presented. There is 400 MW heat power crossing CIB （core interface boundary）. The heat flux profiles and peak flux at the divertor targets with different boundary densities axe investigated. It is indicated that the HCSB-DEMO divertor should operate at a proper upstream density in order to avoid a high heat flux at the divertor targets. When the upstream density is 0.63x 102~ m-3, the peak heat flux at the divertor targets will be above 17 MW/m2. The cross-field transport, the power crossing CIB and the power fraction taken by electrons and ions and SOL （scrape-off-layer） thickness are analyzed as unknown parameters. It is shown that the peak flux at the divertor target is very sensitive to these parameters. The simulation results will be used in the divertor design for HCSB-DEMO.
基金supported by the National Magnetic Confinement Fusion Science Program of China(No.2009GB104008)National Natural Science Foundation of China(Nos.10975048,11175061)
文摘One of the critical issues to be solved for HL-2M is the power exhaust.Divertor target plate geometry strongly influences the plasma profiles by controlling the neutral recycling pattern,which in turn has a strong effect on the symmetry and stability of the divertor plasma and finally on the whole edge region.The numerical simulation SOLPS5.0 package is used to design and explore the divertor target plates for HL-2M.We start with the choice of a proper target plate geometry,which has a smaller incidence angle in the permissible space,and then discuss the method of gas puffing to reduce the heat flux density on the target and the effects of gas puffing on the divertor plasma performance.
基金supported by National Natural Science Foundation of China （No. 10975158）, the National Magnetic Confinenmnt Fusion Research Program of China （Nos. 2009GB106002, 2010GB104005） and in part by the JSPS-CAS Core University program in the field of ＇Plasma and Nuclear Fusion＇
文摘The edge transport code SOLPS5.0 is used to model edge plasmas in the experi- mental shots on JT-60U and the profiles of the transverse particle and heat transport coefficients D, Xe and Xi along the outer midplane are obtained by fitting the simulational results to the experimental data in L-mode shot 39090 and H-mode shots 37851, 37856. The modelling and fitting results show that within the pedestal region in H-mode shots 37851 and 37856 the radial particle transport coefficient D exhibits a significant drop, but, for L-mode shot 39090, the obvious drop in both D and Xe was not found.
基金supported by the National Magnetic Confinement Fusion Science Program of China(No.2009GB104008)National Natural Science Foundation of China(Nos.10975048,11175061)
文摘One of the critical issues to be solved for HL-2M is the power and particle exhaust. Divertor target plate geometry strongly influences the plasma profiles by controlling the neutral recycling pattern, which has in turn a strong effect on the symmetry and stability of the divertor plasma and finally on the whole edge region. The numerical simulation software SOLPS5.0 Pack- age is used to design and explore the divertor target plates for HL-2M. We choose two divertor geometries, and assess the heat flux on the target plates and first wall, then further discuss the di- vertor plasma parameters, and how private flux baffling affects both neutral recirculation pattern and pumping efficiency.
基金supported by National Natural Science Foundation of China(nos. 11405213,11575236,11275231,11305206)the National Magnetic Confinement Fusion Science Program of China (nos.2013GB107003,2014GB106005,2015GB101000)
文摘The edge plasma code package SOLPS5.0 is employed to simulate the divertor power footprint widths of the experimental advanced superconducting tokamak （EAST） L-mode and ELM-free H-mode plasmas.The divertor power footprint widths,which consist of the scrape-off layer （SOL） width λq and heat spreading S,are important physical parameters for edge plasmas.In this work,a plasma current scan is implemented in the simulation to obtain the dependence of the divertor power footprint width on the plasma current Ip.Strong inverse scaling of the SOL width with Ip has been achieved for both L-mode and H-mode plasmas in the forms of λq,L-mode =4.98 × Ip-0.68 and λq,H-mode =1.86 × Ip-1.08.Similar trends have also been demonstrated in the study of heat spreading with SL-mode =1.95 × Ip-0.542 and SH-mode =0.756 × Ip-0.872.In addition,studies on divertor peak heat load and the magnetic flux expansion factor show that both of them are proportional to plasma current.The simulation work here can act as a way to explore the power footprint widths of future tokamak fusion devices such as ITER and the China Fusion Engineering Test Reactor （CFETR）.
基金supported by Chinese National Natural Science Foundation(No.10135020)the JSPS-CAS Core-University Program on Plasma and Nuclear Fusion
文摘A detailed study of the divertor performance in EAST has been performed for both its double null （DN） and single null （SN） configurations. The results of application of the SOLPS （B2-Eirene） code package to the analysis of the EAST divertor are summarized. In this work, we concentrate on the effects of increased geometrical closure and of magnetic topology variation on the scrape-off layer （SOL） and divertor plasma behavior. The results of numerical predictions for the EAST divertor operational window are also described in this paper. A simple Core-SOL- Divertor （C-S-D） model was applied to investigate the possibility of extending plasma operational space of low hybrid current drive （LHCD） experiments for EAST.
文摘A comparative study of SN （single null）, DDN （disconnected double-null） and DN （double null） diverters for HCSB-DEMO （helium-cooled solid breeder, HCSB） is reported in this paper by using the 2D edge plasma transport code SOLPS5.0. There is a heat power of 400 MW crossing CIB （core interface boundary）. The peak heat flux at targets with different upstream densities is investigated. It is indicated that the peak heat flux at the outer target with a SN diverter is lower than that at the outer-down target with a DDN diverter under the same upstream density, but is higher than that at the outer target with a DN diverter. The diverter should operate at a proper upstremn density to avoid strong high heat flux at the targets. The peak heat flux at the targets and first wail are sensitive to the SOL （scrape-off-layer） grid thickness. The simulated results wilt provide data for the design of diverter in HCSB-DEMO.
文摘The effect of poloidal E × B and diamagnetic drifts in edge plasma of Small Size Divertor (SSD) Tokamak is studied with two-dimensional B2SO- LPS-0.5.2D fluid transport code. The simulation results show the following: 1) For normal toroidal magnetic field, the increasing of core plasma density leads to large divertor asymmetries due to poloidal E × B and diamagnetic drifts. 2) Switching on the E × B and diamagnetic drifts leads to large change in poloidal distribution of radial electric field and induced counter-clockwise circulation (flow) around the x-point. 3) Switching on the E × B and diamagnetic drifts leads to the structure of poloidal distribution of radial electric field is nonmonotonic which responsible for negative spikes. 4) Switching on the E × B and diamagnetic drifts in vicinity of separatrix leads to the structure of poloidal distribution of radial electric field that has viscous layer. 5) Switching on the E × B and diamagnetic drifts results in torque generation. This torque spins up the toroidal rotation. 6) The E × B drift velocity depends on the plasma temperature heating and doesn't depend on plasma density.
文摘A low density plasma edge of small size divertor tokamak has been modeling by “B2SOLPS0.5.2 D” fluid transport code. The results of modeling are: 1) Formation of the strong “ITB” has detected more reliable with discovery that, low density plasma is necessary and important condition for it to form. 2) Reduction of plasma density play significantly role in the formation of the strong ITB as global parameter, possibly through change in the steep density gradient which stabilize “ITG” mode. 3) The radial electric field of small size divertor tokamak plasma edge is plasma density dependence and maximum radial electric field shear is found at low plasma density. 4) In the “NBI” discharge the toroidal (parallel) velocity at low plasma density is co-current and upward direction. 5) The structure of plasma pressure and radial electric field in quiescent H-mode are obtained.
文摘Asymmetries between the divertor legs of small size divertor (SSD) tokamak plasma edge are noticed to reverse when the direction of toroidal magnetic field is reversed. In the present paper the small size divertor tokamak plasma edge under effect of toroidal magnetic field reversal is simulated by B2SOLPS0.5.2D fluid transport code. The simulation demonstrate the following results: 1) Parallel (toroidal) flow flux and Mach number up to 0.6 at higher plasma density reverse with reverse toroidal magnetic direction in the edge plasma of small size divertor tokamak. 2) The radial electric field is toroidal magnetic direction independence in edge plasma of small size divertor tokamak. 3) For normal and reverse toroidal magnetic field, the strong ITB is located between the positions of the maximum and minimum values of the radial electric field shear. 4) Simulation result shows that, the structure of radial electric field at high field side (HFS) and low field side (LFS) is different. This difference result from the change in the parallel flux flows in the scrape off layer (SOL) to plasma core through separatrix. 5) At a region of strong radial electric field shear, a large reduction of poloidal rotation was observed. 6) The poloidal rotation is toroidal magnetic field direction dependence.
