Control of edge localized modes by pedestal deposited impurity in the HL-2A tokamak
Control of edge localized modes by pedestal deposited impurity in the HL-2A tokamak
复制标题
DOI：
10.1088/1741-4326/aaae81
复制
发表时间：
2018-02
期刊：
影响因子：
3.3
通讯作者：
Y.P. Zhang;D. Mazon;X. Zou;W. Zhong;J.M. Gao;K. Zhang;P. Sun;C. Dong;Z. Cui;Yi Liu;Z. Shi;D. L. Yu;J. Cheng;M. Jiang;J.Q. Xu;M. Isobe;G. Xiao;W. Chen;S. Song;X. Bai;P. Zhang;G. Yuan;X. Ji;Y.G. Li;Y. Zhou;L. Delpech;A. Ekedahl;G. Giruzzi;T. Hoang;Y. Peysson;X. Song;X.Y. Song;X. Li;X. Ding;J. Dong;Q.W. Yang;M. Xu;X. Duan;Y. Liu
中科院分区：
文献类型：
--
作者：
Y.P. Zhang;D. Mazon;X. Zou;W. Zhong;J.M. Gao;K. Zhang;P. Sun;C. Dong;Z. Cui;Yi Liu;Z. Shi;D. L. Yu;J. Cheng;M. Jiang;J.Q. Xu;M. Isobe;G. Xiao;W. Chen;S. Song;X. Bai;P. Zhang;G. Yuan;X. Ji;Y.G. Li;Y. Zhou;L. Delpech;A. Ekedahl;G. Giruzzi;T. Hoang;Y. Peysson;X. Song;X.Y. Song;X. Li;X. Ding;J. Dong;Q.W. Yang;M. Xu;X. Duan;Y. Liu
在HL-2A装置上观察和研究了基座杂质对边缘局域模（ELM）行为的影响。杂质已外部播种的新开发的激光吹离（LBO）系统。通过LBO籽晶杂质实现了ELMs的缓解和抑制。测量表明，LBO籽晶杂质颗粒主要沉积在基座区。在ELM缓解阶段，基座密度波动显著增加，表明ELM缓解可以通过增强基座输运来实现。当LBO接种杂质的数量超过阈值时，触发从ELM缓解到ELM抑制的转变。在ELM抑制阶段，LBO籽晶杂质激发出谐波相干模（HCM），基座密度起伏显著减小，电子密度持续增加，表明HCM可以降低基座湍流，抑制ELM，增加基座压强，从而扩展Peeling-discrioning不稳定性极限。结果表明，ELM的抑制和减轻与LBO激光光斑直径密切相关。
Effect of the pedestal deposited impurity on the edge-localized mode (ELM) behaviour has been observed and intensively investigated in the HL-2A tokamak. Impurities have been externally seeded by a newly developed laser blow-off (LBO) system. Both mitigation and suppression of ELMs have been realized by LBO-seeded impurity. Measurements have shown that the LBO-seeded impurity particles are mainly deposited in the pedestal region. During the ELM mitigation phase, the pedestal density fluctuation is significantly increased, indicating that the ELM mitigation may be achieved by the enhancement of the pedestal transport. The transition from ELM mitigation to ELM suppression was triggered when the number of the LBO-seeded impurity exceeds a threshold value. During the ELM suppression phase, a harmonic coherent mode (HCM) is excited by the LBO-seeded impurity, and the pedestal density fluctuation is significantly decreased, the electron density is continuously increased, implying that HCM may reduce the pedestal turbulence, suppress ELMs, increase the pedestal pressure, thus extending the Peeling–Ballooning instability limit. It has been found that the occurance of the ELM mitigation and ELM suppression closely depends on the LBO laser spot diameter.