In recent EAST experiments,current profile broadening characterized by reduced internal inductance has been achieved by utilizing radio-frequency current drives(RFCD).In contrast to previous density scan experiments,w...In recent EAST experiments,current profile broadening characterized by reduced internal inductance has been achieved by utilizing radio-frequency current drives(RFCD).In contrast to previous density scan experiments,which showed an outward shift of the current density profile of lower hybrid current drive(LHCD)in higher plasma density,the core electron temperature(T_(e)(0))is found to affect the LHCD current profile as well.According to equilibrium reconstruction,a significant increase in on-axis safety factor(q0)from 2.05 to 3.41 is observed by careful arrangement of RFCD.Simulations using ray-tracing code GENRAY and Fokker–Planck code CQL3D have been performed to thoroughly analyze the LHCD current profile,revealing the sensitivity of the LHCD current profile to T_(e)(0).The LHCD current density tends to accumulate in the plasma core with higher current drive efficiency benefiting from higher T_(e)(0).With a lower T_(e)(0),the LHCD current profile broadens due to off-axis deposition of power density.The sensitivity of the power deposition and current profile of LHCD to T_(e)(0)provides a promising way to effectively optimize current profile via control of the core electron temperature.展开更多
基金supported by the National MCF Energy R&D Program of China (No. 2019YFE0304000)National Natural Science Foundation of China (Nos. 12005262 and 11975274)+3 种基金the Anhui Provincial Natural Science Foundation (No. 2108085J06)the Users with Excellence Program of Hefei Science Center CAS (Nos. 2021HSC-UE018 and 2020HSC-UE011)the External Cooperation Program of Chinese Academy of Sciences (No. 116134KYSB20180035)the Science Foundation of Institute of Plasma Physics, Chinese Academy of Sciences (No. DSJJ-2021-04)
文摘In recent EAST experiments,current profile broadening characterized by reduced internal inductance has been achieved by utilizing radio-frequency current drives(RFCD).In contrast to previous density scan experiments,which showed an outward shift of the current density profile of lower hybrid current drive(LHCD)in higher plasma density,the core electron temperature(T_(e)(0))is found to affect the LHCD current profile as well.According to equilibrium reconstruction,a significant increase in on-axis safety factor(q0)from 2.05 to 3.41 is observed by careful arrangement of RFCD.Simulations using ray-tracing code GENRAY and Fokker–Planck code CQL3D have been performed to thoroughly analyze the LHCD current profile,revealing the sensitivity of the LHCD current profile to T_(e)(0).The LHCD current density tends to accumulate in the plasma core with higher current drive efficiency benefiting from higher T_(e)(0).With a lower T_(e)(0),the LHCD current profile broadens due to off-axis deposition of power density.The sensitivity of the power deposition and current profile of LHCD to T_(e)(0)provides a promising way to effectively optimize current profile via control of the core electron temperature.
