M. Yakovlev, S. Inagaki, T. Shimozuma, S. Kubo, T. Morisaki, Y. Nagayama, K. Kawahata, A. Komori
{"title":"Heat Pulse Propagation across the Rational Surface in Large Helical Device Plasma with Counter Neutral Beam Injection","authors":"M. Yakovlev, S. Inagaki, T. Shimozuma, S. Kubo, T. Morisaki, Y. Nagayama, K. Kawahata, A. Komori","doi":"10.1063/1.2044447","DOIUrl":null,"url":null,"abstract":"Core electron temperature profile flattening is observed in a large helical device [A. Iiyoshi et al. Nucl. Fusion 39, 1245 (1999)] inward shifted plasma with counter-neutral beam injection. To study this phenomenon, heat pulse experiments are performed by on-axis electron cyclotron heating power modulation. A unique feature of heat pulse propagation is observed near the m∕n=2∕1 rational surface (m, n are the poloidal and toroidal mode numbers, respectively). A simultaneous response of the temperature perturbation on radially separated flux surfaces is shown. The change in the magnetic field topology due to the presence of a magnetic island structure can explain this nonmonotonic heat pulse propagation. The estimated O-point position of the island is located near the m∕n=2∕1 rational surface.","PeriodicalId":7974,"journal":{"name":"Annual Report of National Institute for Fusion Science","volume":"69 3 1","pages":"15"},"PeriodicalIF":0.0000,"publicationDate":"2005-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"8","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Annual Report of National Institute for Fusion Science","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.1063/1.2044447","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 8
Abstract
Core electron temperature profile flattening is observed in a large helical device [A. Iiyoshi et al. Nucl. Fusion 39, 1245 (1999)] inward shifted plasma with counter-neutral beam injection. To study this phenomenon, heat pulse experiments are performed by on-axis electron cyclotron heating power modulation. A unique feature of heat pulse propagation is observed near the m∕n=2∕1 rational surface (m, n are the poloidal and toroidal mode numbers, respectively). A simultaneous response of the temperature perturbation on radially separated flux surfaces is shown. The change in the magnetic field topology due to the presence of a magnetic island structure can explain this nonmonotonic heat pulse propagation. The estimated O-point position of the island is located near the m∕n=2∕1 rational surface.