Core and edge turbulences were measured by Langmuir probe arrays in the KT-5C tokamak plasma.The radial wavenumber spectra show a quasimode like structure which results in a net radial outward propagation of the turbu...Core and edge turbulences were measured by Langmuir probe arrays in the KT-5C tokamak plasma.The radial wavenumber spectra show a quasimode like structure which results in a net radial outward propagation of the turbulent fluctuations.The measured fluctuation levels and wave action fluxes are in good agreement with model predictions by Mattor et al.,suggesting that drift wave propagation could be a source of edge turbulence.展开更多
We investigate the possibility of the usage of displaced current in Langmuir probe measurement theoretically and experimentally.The displaced current flows through the self-generated or artificial capacitance of the r...We investigate the possibility of the usage of displaced current in Langmuir probe measurement theoretically and experimentally.The displaced current flows through the self-generated or artificial capacitance of the reference electrode under an alternative sweep voltage.It can increase the total current afforded by the reference electrode,and eliminate the interference deriving from the finite plasma sheath resistance of the reference electrode.The results in both theory and experiment lead to the conclusion that the usage of displaced current is valid and more efficient with a floating probe method.This method is applied in some harsh plasma environments when the grounded chamber wall can easily be contaminated by the dielectric.展开更多
A low-frequency(f<2 kHz)potential structure(LFPS)is observed in a linear magnetic plasma device using Langmuir probe arrays.The center frequency of this structure is near zero.This structure has azimuthal and axial...A low-frequency(f<2 kHz)potential structure(LFPS)is observed in a linear magnetic plasma device using Langmuir probe arrays.The center frequency of this structure is near zero.This structure has azimuthal and axial symmetries while with a finite radial wavenumber.The complete 3D spectra features of this structure have been identified to have the characteristics expected for zonal flows.展开更多
Time-resolved Thomson scattering was successfully performed to diagnose the parameters(ZTe,Ue and Ui)of laser-produced gold plasma.The results show that the collisionless dynamic form factor is accurate enough to be u...Time-resolved Thomson scattering was successfully performed to diagnose the parameters(ZTe,Ue and Ui)of laser-produced gold plasma.The results show that the collisionless dynamic form factor is accurate enough to be used for reducing the plasma parameters from the experimental data.展开更多
Time and space resolved measurements of the radial electric field(Er)have been conducted during the electrode biasing experiments on the KT-5C tokamak.The suppression of the turbulent transport with the change of Er i...Time and space resolved measurements of the radial electric field(Er)have been conducted during the electrode biasing experiments on the KT-5C tokamak.The suppression of the turbulent transport with the change of Er induced by the biased electrode is observed.It is found that the poloidal flow contributes to the main part of the Er,and the change of the poloidal flow has a lead of about 20μs to the formation of Er.These observations suggest that a radial current,responding to an induced voltage on the electrode,drives a poloidal flow which in turn drives the radial electric field.展开更多
Features of a low frequency ion mode were observed together with the electron drift wave type fluctuations by a Langmuir probe array in the bulk plasma inside the velocity shear layer in the KT-5C tokamak.The measured...Features of a low frequency ion mode were observed together with the electron drift wave type fluctuations by a Langmuir probe array in the bulk plasma inside the velocity shear layer in the KT-5C tokamak.The measured ion mode wavenumber,scaling of the ion mode with chord-averaged density,and the estimatedηi value suggest that the observed ion mode may be the theoretically predictedηi mode driven by ion temperature gradient.展开更多
It is found on KT-5C tokamak that an edge fluctuation mode can be excited by using a pair of floating Langmuir probes.This mode is propagating along the magnetic field with its amplitude decreasing drastically when it...It is found on KT-5C tokamak that an edge fluctuation mode can be excited by using a pair of floating Langmuir probes.This mode is propagating along the magnetic field with its amplitude decreasing drastically when it is off the magnetic field line.Preliminary feedback experiments show that the broadband edge turbulence can be reduced or enhanced depending upon the phase shift of the feedback network.展开更多
A new feature in the Thomson scattering spectrum is observed from a laser-produced aluminium plasma, which may be the Thomson scattering off entropy waves in the plasma. Such a feature is only observable when the ener...A new feature in the Thomson scattering spectrum is observed from a laser-produced aluminium plasma, which may be the Thomson scattering off entropy waves in the plasma. Such a feature is only observable when the energy of the heater beam is low enough.展开更多
基金Supported by the National Natural Science Foundation of China under Grant Nos.19675036,19635020the Doctoral Training Foundation of National Education Commission of China and Chinese Academy of Sciences.
文摘Core and edge turbulences were measured by Langmuir probe arrays in the KT-5C tokamak plasma.The radial wavenumber spectra show a quasimode like structure which results in a net radial outward propagation of the turbulent fluctuations.The measured fluctuation levels and wave action fluxes are in good agreement with model predictions by Mattor et al.,suggesting that drift wave propagation could be a source of edge turbulence.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10675121,10705028 and 10835009the ITER Domestic Program of China under Grant Nos 2009GB107000 and 2010GB107000.
文摘We investigate the possibility of the usage of displaced current in Langmuir probe measurement theoretically and experimentally.The displaced current flows through the self-generated or artificial capacitance of the reference electrode under an alternative sweep voltage.It can increase the total current afforded by the reference electrode,and eliminate the interference deriving from the finite plasma sheath resistance of the reference electrode.The results in both theory and experiment lead to the conclusion that the usage of displaced current is valid and more efficient with a floating probe method.This method is applied in some harsh plasma environments when the grounded chamber wall can easily be contaminated by the dielectric.
基金Supported by the National Natural Science Foundation of China under Grant Nos 10875124 and 10605025the National Basic Research Program of China under Grant No 2008CB717800+2 种基金Research Fund for the Doctoral Program of Higher Education of China under Grant No 20060358059the ITER domestic program of China under Grant No 2010GB107000the Knowledge Innovation Program of Chinese Academy of Sciences under Grant No kjcx-yw-n28.
文摘A low-frequency(f<2 kHz)potential structure(LFPS)is observed in a linear magnetic plasma device using Langmuir probe arrays.The center frequency of this structure is near zero.This structure has azimuthal and axial symmetries while with a finite radial wavenumber.The complete 3D spectra features of this structure have been identified to have the characteristics expected for zonal flows.
基金Supported by the National High Technology Programs on Inertial Confinement Fusion(No.416-3-1.2)the National Natural Science Foundation of China under Grant No.19905009,Foundation of the Laboratory for Laser Fusion.
文摘Time-resolved Thomson scattering was successfully performed to diagnose the parameters(ZTe,Ue and Ui)of laser-produced gold plasma.The results show that the collisionless dynamic form factor is accurate enough to be used for reducing the plasma parameters from the experimental data.
基金Supported by the National Natural Science Foundation of China under Grant Nos.19635020,19675036,19775046the Chinese Academy of Sciences,and the National Doctoral Training Foundation under Grant Nos.9535806,9803810.
文摘Time and space resolved measurements of the radial electric field(Er)have been conducted during the electrode biasing experiments on the KT-5C tokamak.The suppression of the turbulent transport with the change of Er induced by the biased electrode is observed.It is found that the poloidal flow contributes to the main part of the Er,and the change of the poloidal flow has a lead of about 20μs to the formation of Er.These observations suggest that a radial current,responding to an induced voltage on the electrode,drives a poloidal flow which in turn drives the radial electric field.
基金Supported by the National Natural Science Foundation of China under Grant No.19275041the Doctoral Training Foundation of National Education Commission of China,and the Chinese Academy of Sciences.
文摘Features of a low frequency ion mode were observed together with the electron drift wave type fluctuations by a Langmuir probe array in the bulk plasma inside the velocity shear layer in the KT-5C tokamak.The measured ion mode wavenumber,scaling of the ion mode with chord-averaged density,and the estimatedηi value suggest that the observed ion mode may be the theoretically predictedηi mode driven by ion temperature gradient.
基金Supported by the Fund of the Chinese Academy of Sciences,and the National High Technology Program of China.
文摘It is found on KT-5C tokamak that an edge fluctuation mode can be excited by using a pair of floating Langmuir probes.This mode is propagating along the magnetic field with its amplitude decreasing drastically when it is off the magnetic field line.Preliminary feedback experiments show that the broadband edge turbulence can be reduced or enhanced depending upon the phase shift of the feedback network.
基金Supported by the National High Technology Programme on Inertial Confinement Fusion(416-3-1.2)in part by the National Natural Science Foundation of China under Grant No.19905009。
文摘A new feature in the Thomson scattering spectrum is observed from a laser-produced aluminium plasma, which may be the Thomson scattering off entropy waves in the plasma. Such a feature is only observable when the energy of the heater beam is low enough.
