The effect of differential biasing of the divertor plates in a tokamak is analyzed using SOLPS-ITER modeling with account of drifts and currents in the SOL. The ASDEX-Upgrade like geometry and transport parameters adjusted for modeling of the semi-detached nitrogen-seeded plasma of shot #28903 are used in analysis. The additional voltage is applied to the outer divertor plate with respect to the grounded vacuum chamber and the inner divertor plate. When high negative voltage is applied, the high field side high density region almost disappears and the divertor plates become more symmetrical than without biasing, while in the case with positive voltage, the formation of the X-point radiator begins, and both divertor plates become more detached. The results are qualitatively consistent with the experiments conducted on the JFT-2 M and DIII-D tokamaks. In addition, both signs of the applied voltage lead to a significant redistribution of the nitrogen within the SOL. Therefore, the possibility of edge plasma control by biasing is demonstrated.
利用 SOLPS-ITER 模型分析了托卡马克中分流板不同偏压的影响,并考虑了 SOL 中的漂移和电流。在分析中使用了 ASDEX-Upgrade 类似的几何形状和传输参数,这些参数已针对 28903 号实验数据的半分离氮封等离子体建模进行了调整。相对于接地真空室和内岔流板,在外侧岔流板上施加附加电压。当施加高负压时,高场侧高密度区几乎消失,辐照板变得比不施加偏压时更加对称;而在施加正电压的情况下,X 点辐射器开始形成,两块辐照板变得更加分离。这些结果与在 JFT-2 M 和 DIII-D 托卡马克上进行的实验在性质上是一致的。此外,外加电压的两种符号都会导致氮在 SOL 内发生显著的重新分布。因此,通过偏压控制边缘等离子体的可能性得到了证实。
{"title":"Control of edge plasma by plate biasing in SOLPS-ITER modeling","authors":"V. A. Rozhansky, A. A. Shirobokov, E. G. Kaveeva","doi":"10.1002/ctpp.202300122","DOIUrl":"10.1002/ctpp.202300122","url":null,"abstract":"<p>The effect of differential biasing of the divertor plates in a tokamak is analyzed using SOLPS-ITER modeling with account of drifts and currents in the SOL. The ASDEX-Upgrade like geometry and transport parameters adjusted for modeling of the semi-detached nitrogen-seeded plasma of shot #28903 are used in analysis. The additional voltage is applied to the outer divertor plate with respect to the grounded vacuum chamber and the inner divertor plate. When high negative voltage is applied, the high field side high density region almost disappears and the divertor plates become more symmetrical than without biasing, while in the case with positive voltage, the formation of the X-point radiator begins, and both divertor plates become more detached. The results are qualitatively consistent with the experiments conducted on the JFT-2 M and DIII-D tokamaks. In addition, both signs of the applied voltage lead to a significant redistribution of the nitrogen within the SOL. Therefore, the possibility of edge plasma control by biasing is demonstrated.</p>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":null,"pages":null},"PeriodicalIF":1.3,"publicationDate":"2024-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139515440","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yutian Yu, Li Wu, Qiang Chen, Naoki Shinohara, Kama Huang
This study investigates the counterintuitive behaviors of a microwave-induced atmospheric pressure plasma jet (APPJ) under the influence of an external electrostatic field applied by one or a pair of parallel electrode plates subjected to DC voltages. The findings demonstrate that the plasma jet consistently deflects toward the electrode plate with an electrostatic potential, irrespective of the direction of the applied field. The deflection becomes more pronounced with increasing voltage on the electrode plate until the ionic wind generated by the high voltage significantly affects the jet's behavior. Remarkably, a negative voltage induces a greater deflection compared to a positive voltage. To further investigate this discovery, the dielectric properties and the non-neutral characteristics of the APPJ are analyzed, and the simulations of the electric field distribution reveal a non-uniform distribution, which plays a crucial role in understanding the mechanism behind the observed behaviors of the plasma jet. This study provides a comprehensive understanding of the underlying mechanism driving the observed phenomena and sheds light on the collective behavior of plasma jets under non-uniform electric fields. The findings of this study offer valuable guidelines for investigating and controlling the behavior of APPJs.
{"title":"Exploring the connection between non-uniform electrostatic fields generated by opposite polarity voltages and the behavior of atmospheric pressure plasma jet","authors":"Yutian Yu, Li Wu, Qiang Chen, Naoki Shinohara, Kama Huang","doi":"10.1002/ctpp.202300100","DOIUrl":"10.1002/ctpp.202300100","url":null,"abstract":"<p>This study investigates the counterintuitive behaviors of a microwave-induced atmospheric pressure plasma jet (APPJ) under the influence of an external electrostatic field applied by one or a pair of parallel electrode plates subjected to DC voltages. The findings demonstrate that the plasma jet consistently deflects toward the electrode plate with an electrostatic potential, irrespective of the direction of the applied field. The deflection becomes more pronounced with increasing voltage on the electrode plate until the ionic wind generated by the high voltage significantly affects the jet's behavior. Remarkably, a negative voltage induces a greater deflection compared to a positive voltage. To further investigate this discovery, the dielectric properties and the non-neutral characteristics of the APPJ are analyzed, and the simulations of the electric field distribution reveal a non-uniform distribution, which plays a crucial role in understanding the mechanism behind the observed behaviors of the plasma jet. This study provides a comprehensive understanding of the underlying mechanism driving the observed phenomena and sheds light on the collective behavior of plasma jets under non-uniform electric fields. The findings of this study offer valuable guidelines for investigating and controlling the behavior of APPJs.</p>","PeriodicalId":10700,"journal":{"name":"Contributions to Plasma Physics","volume":null,"pages":null},"PeriodicalIF":1.6,"publicationDate":"2024-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139499267","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Distribution of internal plasma channel temperature and rock conductivity under different magnetic field conditions. Fig. 9 of the paper by Weiji Liu et al., https://doi.org/10.1002/ctpp.202300086