为在低杂波电流驱动(LHCD)系统打火等严重故障时及时保护高压电源,提出了设置三电极气体开关作为第一级快保护方案,并研制了一套能通流60 k A、5μs快速导通的三电极气体开关。通过联合LHCD高压电源与开关进行短路故障保护实验,证明了...为在低杂波电流驱动(LHCD)系统打火等严重故障时及时保护高压电源,提出了设置三电极气体开关作为第一级快保护方案,并研制了一套能通流60 k A、5μs快速导通的三电极气体开关。通过联合LHCD高压电源与开关进行短路故障保护实验,证明了开关工作性能稳定,大大提高了LHCD高压电源运行的安全性与可靠性,在脉冲功率装置中具有较好的应用前景。展开更多
A transport simulation has been done by using a i.5D time dependent transportcode to reproduce a formation of the ITB on electron temperature Profile during the long pu1seLHCD in JT-60U tokamak. The transport coeffici...A transport simulation has been done by using a i.5D time dependent transportcode to reproduce a formation of the ITB on electron temperature Profile during the long pu1seLHCD in JT-60U tokamak. The transport coefficients were assumed to reduce with a reversedmagnetic shear and the LH driven current profile was evaluated by fitting dynamic change inthe measured current profile. The gradual increase in the central electron temperature could beexplained by the change in the current profile during LHCD in the present simulation model. Theestimated LH-driven current profile by the transport code analysis shows a finite current densityat the plasma center. Analysis of transport simulation suggests some mechanisms for broadeningthe LH-driven current profile at the central region of the plasma.展开更多
In this paper, the composition of HT-7 LHCD system along with its protection systems is introduced. It is very important for us to run the LHCD system safely and efficiently.
The efficiency of lower hybrid current drive （LHCD） for limiter and divertor con- figurations in the EAST tokamak is investigated using hot electrical conductivity theory and experimental formulas. The results indic...The efficiency of lower hybrid current drive （LHCD） for limiter and divertor con- figurations in the EAST tokamak is investigated using hot electrical conductivity theory and experimental formulas. The results indicate that the efficiency of current drive in divertor geometry is slightly higher than that in limiter one. To interpret the experimental results, the GENRAY code is applied to calculate the propagation and absorption of the lower hybrid wave （LHW） in different configurations. The numerical results show that the variation in the parallel refractive index （N//） between the two configurations is quite large. Transformer recharging experiments were also successfully conducted in EAST. By means of the Karney-Fisch method, the absorption index （α） and the upshift factor of refraction （β） for the LHW are obtained. In addition, the maximum recharging efficiency in EAST is about 4% in the divertor configuration, with a line-averaged electron density of ne_av=0.7×10^19m^-3展开更多
Divertor heat patterns induced by Lower Hybrid Current Drive （LHCD） L-mode plasmas are investigated using an infra-red （IR） camera system on an Experimental Advanced Superconducting Tokamak （EAST）. A two-dimensi...Divertor heat patterns induced by Lower Hybrid Current Drive （LHCD） L-mode plasmas are investigated using an infra-red （IR） camera system on an Experimental Advanced Superconducting Tokamak （EAST）. A two-dimensional finite element analysis code DFlux is used to compute heat flux along the poloidal divertor target and corresponding quantities. Outside the Origin Strike Zone （OSZ）, a Second Peak Heat Flux （SPHF） zone, where the heat flux is even stronger than that at the OSZ, appears on the lower-outer （LO） divertor plates with LHCD and disappears immediately after switching off the LHCD. The main heat-flux shifts from the SPHF zone towards the OSZ when the divertor configuration converts from double null to lower single null, indicating that the growth of the SPHF zone is apparently affected by a plasma magnetic configuration. The heat patterns on the LO divertor plates are observed to be different from that on the lower-inner （LI） targets as the SPHF zone appears only on the LO divertor target. It is also found that the heat flux at the SPHF zone was obviously enhanced after the Supersonic Molecule Beam Injection （SMBI） pulse.展开更多
文摘为在低杂波电流驱动(LHCD)系统打火等严重故障时及时保护高压电源,提出了设置三电极气体开关作为第一级快保护方案,并研制了一套能通流60 k A、5μs快速导通的三电极气体开关。通过联合LHCD高压电源与开关进行短路故障保护实验,证明了开关工作性能稳定,大大提高了LHCD高压电源运行的安全性与可靠性,在脉冲功率装置中具有较好的应用前景。
文摘A transport simulation has been done by using a i.5D time dependent transportcode to reproduce a formation of the ITB on electron temperature Profile during the long pu1seLHCD in JT-60U tokamak. The transport coefficients were assumed to reduce with a reversedmagnetic shear and the LH driven current profile was evaluated by fitting dynamic change inthe measured current profile. The gradual increase in the central electron temperature could beexplained by the change in the current profile during LHCD in the present simulation model. Theestimated LH-driven current profile by the transport code analysis shows a finite current densityat the plasma center. Analysis of transport simulation suggests some mechanisms for broadeningthe LH-driven current profile at the central region of the plasma.
文摘In this paper, the composition of HT-7 LHCD system along with its protection systems is introduced. It is very important for us to run the LHCD system safely and efficiently.
基金supported by National Natural Science Foundation of China (Nos.10875149, 10928509 and 10805057)the National Magnetic Confinement Fusion Science Program of China (No.2010GB105004)
文摘The efficiency of lower hybrid current drive （LHCD） for limiter and divertor con- figurations in the EAST tokamak is investigated using hot electrical conductivity theory and experimental formulas. The results indicate that the efficiency of current drive in divertor geometry is slightly higher than that in limiter one. To interpret the experimental results, the GENRAY code is applied to calculate the propagation and absorption of the lower hybrid wave （LHW） in different configurations. The numerical results show that the variation in the parallel refractive index （N//） between the two configurations is quite large. Transformer recharging experiments were also successfully conducted in EAST. By means of the Karney-Fisch method, the absorption index （α） and the upshift factor of refraction （β） for the LHW are obtained. In addition, the maximum recharging efficiency in EAST is about 4% in the divertor configuration, with a line-averaged electron density of ne_av=0.7×10^19m^-3
基金supported by the National Magnetic Confinement Fusion Science Program of China(Nos.2014GB101001 and 2014GB101002)
文摘Divertor heat patterns induced by Lower Hybrid Current Drive （LHCD） L-mode plasmas are investigated using an infra-red （IR） camera system on an Experimental Advanced Superconducting Tokamak （EAST）. A two-dimensional finite element analysis code DFlux is used to compute heat flux along the poloidal divertor target and corresponding quantities. Outside the Origin Strike Zone （OSZ）, a Second Peak Heat Flux （SPHF） zone, where the heat flux is even stronger than that at the OSZ, appears on the lower-outer （LO） divertor plates with LHCD and disappears immediately after switching off the LHCD. The main heat-flux shifts from the SPHF zone towards the OSZ when the divertor configuration converts from double null to lower single null, indicating that the growth of the SPHF zone is apparently affected by a plasma magnetic configuration. The heat patterns on the LO divertor plates are observed to be different from that on the lower-inner （LI） targets as the SPHF zone appears only on the LO divertor target. It is also found that the heat flux at the SPHF zone was obviously enhanced after the Supersonic Molecule Beam Injection （SMBI） pulse.
