Correlation of electrostatic fluctuation and reversal of toroidal field in the reversed-field pinch plasma

Yambe, Kiyoyuki; Koguchi, Haruhisa; Sakakita, Hajime; Hirano, Yoichi; Kiyama, Satoru
June 2011
Physics of Plasmas;Jun2011, Vol. 18 Issue 6, p064505
Academic Journal
The magnetic fluctuations and electrostatic probe potential have been measured in the Toroidal Pinch Experiment - RX (TPE-RX) reversed-field pinch plasma [Y. Yagi et al., Fusion Eng. Des. 45, 421 (1999)] (at the plasma surface r/a = 1.00). Fast electrons with energy comparable to or slightly higher than the core electron temperature are observed as many spikes in the electrostatic probe signal. These electrons are diffused by a fluctuating magnetic field from the core region. During the period of mild deepening of the reversal of the edge toroidal field, a significant reduction in the spike signal, increases in electron density and soft x-ray radiation, and a decrease in the Dα line radiation are observed, even though the reduction in magnetic fluctuations is not significant during the same period, which indicates that the mild deepening of the reversal of the toroidal field can improve the confinement of fast electrons.


Related Articles

  • Magnetically insulated baffled probe for real-time monitoring of equilibrium and fluctuating values of space potentials, electron and ion temperatures, and densities. Demidov, V. I.; Koepke, M. E.; Raitses, Y. // Review of Scientific Instruments;Oct2010, Vol. 81 Issue 10, p10E129 

    By restricting the electron-collection area of a cold Langmuir probe compared to the ion-collection area, the probe floating potential can become equal to the space potential, and thus conveniently monitored, rather than to a value shifted from the space potential by an...

  • Confinement of electron plasma by levitating dipole magnet. Saitoh, H.; Yoshida, Z.; Morikawa, J.; Yano, Y.; Hayashi, H.; Mizushima, T.; Kawai, Y.; Kobayashi, M.; Mikami, H. // Physics of Plasmas;Nov2010, Vol. 17 Issue 11, p112111 

    A recent experiment on the Ring Trap 1 device has demonstrated long-term (exceeding 300 s) confinement of non-neutral (pure electron) plasma in a dipole magnetic field; particles diffuse inward, steepening the density gradient and self-organizing into a stable vortex structure [Z. Yoshida et...

  • Spontaneous emission of Weibel fluctuations by anisotropic distributions. Tautz, R. C.; Schlickeiser, R. // Physics of Plasmas;Oct2007, Vol. 14 Issue 10, p102102 

    Recently [Yoon, Phys. Plasmas 14, 064504 (2007)], the spontaneous emission of magnetic field fluctuations in isotropic particle distribution functions was investigated. Here, the question is addressed as to how these fluctuations develop for an anisotropic distribution function that supports the...

  • Magnetic field correlations in random flow with strong steady shear. Kolokolov, I.; Lebedev, V.; Sizov, G. // Journal of Experimental & Theoretical Physics;Aug2011, Vol. 113 Issue 2, p339 

    We analyze the magnetic kinematic dynamo in a conducting fluid where a stationary shear flow is accompanied by relatively weak random velocity fluctuations. The diffusionless and diffusion regimes are described. The growth rates of the magnetic field moments are related to the statistical...

  • Solar wind fluctuations and the von Kármán-Howarth equations: The role of fourth-order correlations. Oughton, Sean; Wan, Minping; Matthaeus, William H.; Servidio, Sergio // AIP Conference Proceedings;Jun2013, Vol. 1539 Issue 1, p251 

    The von Kármán-Howarth (vKH) hierarchy of equations relate the second-order correlations of the turbulent fluctuations to the third-order ones, the third-order to the fourth-order, and so on. We recently demonstrated [1] that for MHD, self-similar solutions to the vKH equations seem to...

  • Towards the Detection of Magnetohydrodynamics Instabilities in a Fusion Reactor. Sozzi, C.; Alessi, E.; Figini, L.; Galperti, G.; Lazzaro, E.; Marchetto, C.; Mosconi, M.; Nowak, S. // AIP Conference Proceedings;2014, Vol. 1612, p35 

    Various active control strategies of the Neoclassical tearing modes are being studied in present tokamaks using established detection techniques which exploit the measurements of the fluctuations of the magnetic field and of the electron temperature. The extrapolation of such techniques to the...

  • Theory of coupled whistler-electron temperature gradient mode in high beta plasma: Application to linear plasma device. Singh, S. K.; Awasthi, L. M.; Singh, R.; Kaw, P. K.; Jha, R.; Mattoo, S. K. // Physics of Plasmas;Oct2011, Vol. 18 Issue 10, p102109 

    This paper presents a theory of coupled whistler (W) and electron temperature gradient (ETG) mode using two-fluid model in high beta plasma. Non-adiabatic ion response, parallel magnetic field perturbation (δBz), perpendicular magnetic flutter (δB⊥), and electron collisions are...

  • Superfluidity of electron-hole pairs in randomly inhomogeneous bilayer systems. Bezuglyj, A. I.; Shevchenko, S. I. // Low Temperature Physics;Jul2011, Vol. 37 Issue 7, p583 

    In bilayer systems, electron-hole (e-h) pairs with spatially separated components can exhibit a transition to a superfluid state. An influence of random inhomogeneities on superfluid properties of bilayer systems is considered. It is shown that ionized impurities and distortions of conducting...

  • Weakly relativistic and ponderomotive effects on the density steepening in the interaction of an intense laser pulse with an underdense plasma. Niknam, A. R.; Hashemzadeh, M.; Shokri, B. // Physics of Plasmas;Mar2009, Vol. 16 Issue 3, p033105 

    The effect of the weakly relativistic ponderomotive force in the interaction of an intense laser pulse with an underdense plasma is studied. This force modifies the electron density distribution. Furthermore, the existence of intense laser pulses in plasma causes the electron relativistic mass...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics