High-density experiments in the high-field-side mid-plane single-null divertor configuration have been performed for the first time on J-TEXT.The experiments show an increase in the highest central channel line-averag...High-density experiments in the high-field-side mid-plane single-null divertor configuration have been performed for the first time on J-TEXT.The experiments show an increase in the highest central channel line-averaged density from 2.73×10^(19)m^(-3) to 6.49×10^(19)m^(-3),while the X-point moves away from the target by increasing the divertor coil current.The corresponding Greenwald fraction rises from 0.50 to 0.79.For the impurity transport,the density normalized radiation intensity(absolute extreme ultraviolet and soft x-ray)of the central channel density decreased significantly(>50%)with an increase in the plasma density.To better understand the underlying physics mechanisms,the 3 D edge Monte Carlo code coupled with EIRENE(EMC3-EIRENE)has been implemented for the first time on J-TEXT.The simulation results show good agreement with the experimental findings.As the X-point moves away from the target,the divertor power decay length drops and the scrape-off layer impurity screening effect is enhanced.展开更多
To extend the operation region of the Joint-Texas Experimental tokamak(J-TEXT) to the divertor configuration and even the H-mode,the divertor configuration discharge has been realized for the first time in the J-TEXT ...To extend the operation region of the Joint-Texas Experimental tokamak(J-TEXT) to the divertor configuration and even the H-mode,the divertor configuration discharge has been realized for the first time in the J-TEXT tokamak.Along with the establishment of a power supply for the divertor configuration,the construction of relevant diagnostics,and the installation of the divertor target on the high-field side,divertor discharge has been tested.Through the equilibrium calculation and position stability analysis,the control strategy has evolved to be more stable.High-density experiments and auxiliary heating experiments have been carried out on the divertor configuration.The special midplane single-null(MSN) divertor configuration is shown to be more stable than the limiter configuration in the density limit condition and can reach a higher density in the experiment.In the ECRH experiment,the power injection enhances the electron temperature and density,while more heat outflux is loaded on the divertor target tiles and causes more intensive recycling and impurity release.The future plan for the divertor configuration operation in the J-TEXT tokamak is also included.展开更多
基金supported by the National Magnetic Confinement Fusion Energy R&D Program of China (Nos.2018YFE0301104 and 2018YFE0309100)National Natural Science Foundation of China (No. 51821005).
文摘High-density experiments in the high-field-side mid-plane single-null divertor configuration have been performed for the first time on J-TEXT.The experiments show an increase in the highest central channel line-averaged density from 2.73×10^(19)m^(-3) to 6.49×10^(19)m^(-3),while the X-point moves away from the target by increasing the divertor coil current.The corresponding Greenwald fraction rises from 0.50 to 0.79.For the impurity transport,the density normalized radiation intensity(absolute extreme ultraviolet and soft x-ray)of the central channel density decreased significantly(>50%)with an increase in the plasma density.To better understand the underlying physics mechanisms,the 3 D edge Monte Carlo code coupled with EIRENE(EMC3-EIRENE)has been implemented for the first time on J-TEXT.The simulation results show good agreement with the experimental findings.As the X-point moves away from the target,the divertor power decay length drops and the scrape-off layer impurity screening effect is enhanced.
基金supported by the National MCF Energy R&D Program of China(Nos.2018YFE0301104 and 2018YFE0310300)National Natural Science Foundation of China(No.51821005)
文摘To extend the operation region of the Joint-Texas Experimental tokamak(J-TEXT) to the divertor configuration and even the H-mode,the divertor configuration discharge has been realized for the first time in the J-TEXT tokamak.Along with the establishment of a power supply for the divertor configuration,the construction of relevant diagnostics,and the installation of the divertor target on the high-field side,divertor discharge has been tested.Through the equilibrium calculation and position stability analysis,the control strategy has evolved to be more stable.High-density experiments and auxiliary heating experiments have been carried out on the divertor configuration.The special midplane single-null(MSN) divertor configuration is shown to be more stable than the limiter configuration in the density limit condition and can reach a higher density in the experiment.In the ECRH experiment,the power injection enhances the electron temperature and density,while more heat outflux is loaded on the divertor target tiles and causes more intensive recycling and impurity release.The future plan for the divertor configuration operation in the J-TEXT tokamak is also included.
