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arXiv · 2304.08336

Validation of the plasma-wall self-organization model for density limit in ECRH-assisted start-up of Ohmic discharges on J-TEXT

Jiaxing Liu·Ping Zhu·Dominique Franck Escande·Junli Zhang·Donghui Xia·Yuhan Wang·Jiaming Wang·Qinghu Yang·Jiangang Fang·Li Gao·Zhifeng Cheng·Zhipeng Chen·Zhoujun Yang·Zhongyong Chen·Yonghua Ding·Yuan Pan·the J-TEXT team
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Abstract

A recently developed plasma-wall self-organization (PWSO) model predicts a significantly enhanced density limit, which may be attainable in tokamaks with ECRH-assisted ohmic startup and sufficiently high initial neutral density. Experiments have been conducted on J-TEXT to validate such a density limit scenario based on this model. Experimental results demonstrate that increasing the pre-filled gas pressure or ECRH power during the startup phase can effectively enhance plasma purity and raise the density limit at the flat-top. Despite the dominant carbon fraction in the wall material, some discharges approach the edge of the density-free regime of the 1D model of PWSO.

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Jiaxing Liu, Ping Zhu, Dominique Franck Escande, Junli Zhang, Donghui Xia, Yuhan Wang, Jiaming Wang, Qinghu Yang, Jiangang Fang, Li Gao, Zhifeng Cheng, Zhipeng Chen, Zhoujun Yang, Zhongyong Chen, Yonghua Ding, Yuan Pan, the J-TEXT team. 2023-04-17. Validation of the plasma-wall self-organization model for density limit in ECRH-assisted start-up of Ohmic discharges on J-TEXT. https://doi.org/10.1088/1741-4326/ace91c

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