Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-27T15:11:28.226Z Has data issue: false hasContentIssue false
  • English
  • Français

Extended possibility of an active control of co-axially nested shear plasma formation due to electron cyclotron heatings

Part of: Solved and Unsolved problems in Plasma Physics

Published online by Cambridge University Press:  19 September 2016

T. Cho  and
M. Hirata
T. Cho*
Affiliation:
Research Institute of Material Science, Tsukuba, Ibaraki 305-0034, Japan
M. Hirata
Affiliation:
Plasma Research Centre, University of Tsukuba, Tsukuba, Ibaraki 305-8577, Japan
*
†Email address for correspondence: [email protected]
Get access Rights & Permissions [Opens in a new window]

Abstract

Coaxially nested intense $E\times B$ sheared flow realized an upgraded stable mirror plasma regime. After such an external control of high vorticity formation due to electron cyclotron heating, significantly unstable plasmas appeared. Thereby, the associated cross-field transport caused a crash of plasmas. Its generalized physics and interpretation could prepare or extend to another possibility of stability in a field-reversed configuration (FRC), for instance. Such underlying physics bases of vorticity formation were essentially or partially performed in tokamaks and stellarators (solved problems). Nevertheless, it remains to be seen whether this mirror-based experimental evidence is applicable or not to open ended FRC devices. This open issue may give a solution of one of unsolved important problems, and possibly provide more generalized and externally controllable opportunities for not only FRC but wider plasma confinement improvements.

Keywords

magnetized plasmasplasma confinementplasma instabilities
Type
Research Article
Information
Journal of Plasma Physics , Volume 82 , Issue 5 , October 2016 , 595820501
Copyright
© Cambridge University Press 2016 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Budker, G. I., Mirnov, V. V. & Ryutov, D. D. 1971 Influence on corrugation of the magnetic field on the expansion and cooling of a dense plasma. J. Expl Theor. Phys. Lett. 14, 212–215.Google Scholar
Cho, T., Kohagura, J., Numakura, T., Hirata, M., Hojo, H., Ichimura, M., Ishii, K., Itakura, A., Katanuma, I., Nakashima, Y. et al. 2001 Generalized scaling laws of the formation and effects of plasma-confining potentials for tandem-mirror operations in GAMMA 10. Phys. Rev. Lett. 19, 4310–4313.Google Scholar
Cho, T., Yoshida, M., Kohagura, J., Hirata, M., Numakura, T., Higaki, H., Hojo, H., Ichimura, M., Ishii, K., Islam, K. Md. et al. & GAMMA 10 group 2005a Observation of the effects of radially sheared electric fields on the suppression of turbulent vortex structures and the associated transverse loss in GAMMA 10. Phys. Rev. Lett. 94, 085002, 1–4.Google Scholar
Cho, T., Kohagura, J., Hirata, M., Numakura, T., Higaki, H., Hojo, H., Ichimura, M., Ishii, K., Islam, K. Md., Itakura, A. et al. & GAMMA 10 group 2005b Progress in potential formation and findings in the associated radially sheared electric-field effects on suppressing intermittent turbulent vortex-like fluctuations and reducing transverse losses. Nucl. Fusion 45, 1650–1657.Google Scholar
Cho, T., Hirata, M. & Pastukhov, V. P. 2006 Observation and control of transverse energy-transport barrier due to the formation of an energetic-electron layer with sheared $\boldsymbol{E}\times \boldsymbol{B}$ flow. Phys. Rev. Lett. 94, 085002, 1–4.Google Scholar
Cho, T. 2007 High confinement in fusion oriented plasma with kV-order potential, ion, and electron temperature with controlled radial turbulent transport in GAMMA 10 GI2-6. Bull. Amer. Phys. Soc. 52, 100 (invited by 49th annual meeting of the division of plasma physics).Google Scholar
Cho, T., Pastukhov, V. P., Horton, W., Numakura, T., Hirata, M., Kohagura, J., Chudin, N. V. & Pratt, J. 2008 Active control of internal transport barrier formation due to off-axis electron-cyclotron heating in GAMMA 10 experiments. Phys. Plasmas 15, 056120, 1–9.Google Scholar
Connor, J. W. & Wilson, H. R. 2000 A review of theories of the L-H transition. Plasma Phys. Control. Fusion 42, R1–R74.Google Scholar
Diamond, P. H., Itoh, S.-I., Itoh, K. & Hahm, T. S. 2005 Zonal flows in plasma. Plasma Phys. Control. Fusion 47, R35–R161.CrossRefGoogle Scholar
Fetterman, A. J. & Fisch, N. J. 2008 $\unicode[STIX]{x1D6FC}$ channeling in a rotating plasma. Phys. Rev. Lett. 101, 205003-1-4.Google Scholar
Fetterman, A. J. & Fisch, N. J. 2010 Alpha channeling in rotating plasma with stationary waves. Phys. Plasmas 17, 042112, 1–6.Google Scholar
Fowler, T. K. & Logan, B. G. 1977 The tandem mirror reactor. Comments Plasma Phys. Control. Fusion 2, 167–172.Google Scholar
Fujita, T., Ide, S., Shirai, H., Kikuchi, M., Naito, O., Koide, Y., Takeji, S., Kubo, H. & Ishida, S. 1997 Internal transport barrier for electrons in JT-60U reversed shear discharges. Phys. Rev. Lett. 78, 2377–2380.Google Scholar
Guo, H. Y., Binderbauer, M. W., Tajima, T., Milroy, R. D., Steinhauer, L. C., Yang, X., Garate, E. G., Gota, H., Korepanov, S., Necas, A. et al. 2015 Achieving a long-lived high-beta plasma state by energetic beam injection. Nature Comm. 6, 6897.CrossRefGoogle ScholarPubMed
Hirata, M., Cho, T., Takahashi, E., Yamaguchi, N., Kondoh, T., Matsuda, K., Aoki, S., Tanaka, K., Maezawa, H. & Miyoshi, S. 1992 X-ray detection characteristics of gold photocathodes and microchannel plates using synchrotron radiation (10 eV–82.5 keV). Nucl. Instrum. Meth. Phys. Res., Sect. B66, 479–484.Google Scholar
Ishii, K., Kotoku, M., Segawa, T., Katanuma, I., Mase, A. & Miyoshi, S. 1989 Thermal barrier potential and two-dimensional space-potential measurements with gold neutral beam probes in GAMMA 10. Rev. Sci. Instrum. 60, 3270–3274.Google Scholar
Kishimoto, Y., Kim, J.-Y., Horton, W., Tajima, T., Lebrun, M. J., Dettrick, S. A., Li, J. Q. & Shirai, S. 2000 Discontinuity model for internal transport barrier formation in reversed magnetic shear plasmas. Nucl. Fusion 40, 667–676.CrossRefGoogle Scholar
Kohagura, J., Cho, T., Hirata, M., Yatsu, K., Tamano, T., Ogasawara, T., Yagishita, A., Sekitani, T. & Maezawa, H. 1995 Detection characteristics of an ultralow energy measurable pure germanium detector in the hundreds eV photon energy region. Rev. Sci. Instrum. 66, 2317–2319.Google Scholar
Pastukhov, V. P. 1974 Collisional losses of electrons from an adiabatic trap in a plasma with a positive potential. Nucl. Fusion 14, 3–6.Google Scholar
Pastukhov, V. P. 2005 Equations for nonlinear MHD convection in shearless magnetic systems. Plasma Phys. Rep. 31, 577–590.Google Scholar
Pastukhov, V. P. & Chudin, N. V. 2011 Turbulent convection and anomalous cross-field transport in mirror plasmas. Fusion Sci. Technol. 59, 84–89.Google Scholar
Post, R. F. 1987 The magnetic mirror approach to fusion. Nucl. Fusion 27, 1579–1739.Google Scholar
Smirnov, A. 2016 C-2U field reversed configuration experiment at Tri Alpha Energy, Inc. Solved and unsolved problems in plasma physics, March 29, 2016. Princeton University.Google Scholar
Takeiri, Y., Morita, S., Ikeda, K., Ida, K., Kubo, S., Yokoyama, M., Tsumori, K., Oka, Y., Osakabe, M., Nagaoka, K. et al. & The LHD Experimental Group 2007 Confinement improvement in high-ion temperature plasmas heated with high-energy negative-ion-based neutral beam injection in the Large Helical Device. Nucl. Fusion 47, 1078–1805.Google Scholar