Reactor prospect of spheromak concept by electrostatic helicity injection

Tang, X. Z.; Boozer, A. H.
July 2008
Physics of Plasmas;Jul2008, Vol. 15 Issue 7, p072510
Academic Journal
The highest performing spheromaks in the laboratory are formed by electrostatic helicity injection. Discharges with up to 1 MA plasma current and core electron temperature as high as 500 eV have been recently obtained. For such a scheme to scale-up to a reactor, however, a much higher current multiplication factor (plasma current over injector current) must be achieved. It is shown here that spheromak current multiplication is linearly proportional to flux amplification (ratio of poloidal fluxes inside and outside the separatrix of the mean field). Hence, spheromak optimization is centered around achieving high flux amplification, which is provided by linear or nonlinear resonant coupling between helicity injector and the spheromak force-free eigenmode. The nonlinear resonant field amplification is the most promising route to high flux amplification in a realistic plasma that often significantly deviates from the Taylor state. Accessing such nonlinear resonant field amplification can be facilitated by auxiliary current drive around the magnetic axis and auxiliary heating to break the electron temperature constraint on flux amplification.


Related Articles

  • Vorticity probes and the characterization of vortices in the Kelvin–Helmholtz instability in the large plasma device experiment. Horton, W.; Perez, Jean C.; Carter, Troy; Bengtson, Roger // Physics of Plasmas;Feb2005, Vol. 12 Issue 2, p022303 

    A new five-pin probe design called the vorticity probe is presented that explicitly measures the vorticity in the E×B flow from floating potentials, independent of any absolute calibration errors. The five Tantalum probe tips are arranged in a diamond pattern with 5 mm tip spacing. The...

  • Advances in the numerical modeling of field-reversed configurations. Belova, Elena V.; Davidson, Ronald C.; Hantao Ji; Yamada, Masaaki // Physics of Plasmas;May2006, Vol. 13 Issue 5, p056116 

    The field-reversed configuration (FRC) is a compact torus with little or no toroidal magnetic field. A theoretical understanding of the observed FRC equilibrium and stability properties presents significant challenges due to the high plasma beta, plasma flows, large ion gyroradius, and the...

  • Scaling laws of resistive magnetohydrodynamic reconnection in the high-Lundquist-number, plasmoid-unstable regime. Yi-Min Huang; Bhattacharjee, A. // Physics of Plasmas;Jun2010, Vol. 17 Issue 6, p062104 

    The Sweet–Parker layer in a system that exceeds a critical value of the Lundquist number (S) is unstable to the plasmoid instability. In this paper, a numerical scaling study has been done with an island coalescing system driven by a low level of random noise. In the early stage, a...

  • Observation of a pressure limit in a gun-driven spheromak. Woodruff, S.; Hooper, E. B.; Pearlstein, L. D.; Bulmer, R.; Hill, D. N.; Holcomb, C. T.; McLean, H. S.; Moller, J.; Stallard, B. W.; Wood, R. D. // Physics of Plasmas;Apr2006, Vol. 13 Issue 4, p044506 

    Density in a spheromak is lowered by action of a m/n=2/4 island, after which the electrons heat rapidly to give profiles of nTbefore=nTafter, indicating that the spheromak heats up to a pressure limit. The spheromak core remains at Te∼150 eV for ∼1/2 ms during a period exhibiting low...

  • Nonlinear dynamics of kink-unstable spheromak equilibria. García-Martínez, Pablo Luis; Farengo, Ricardo // Physics of Plasmas;Aug2009, Vol. 16 Issue 8, p082507 

    The nonlinear evolution of several kink-unstable, force-free equilibria inside a cylindrical flux conserver is studied by solving the nonlinear, three-dimensional, time-dependent equations of resistive magnetohydrodynamics (MHD). The stability properties of the equilibria are controlled by the...

  • Single vortex core recording in a magnetic vortex lattice. Mitin, D.; Nissen, D.; Schädlich, P.; Arekapudi, S. S. P. K.; Albrecht, M. // Journal of Applied Physics;2014, Vol. 115 Issue 6, p1 

    We investigated the reversal characteristics of magnetic vortex cores in a two dimensional assembly of magnetic vortices. The vortex lattice was created by film deposition of 30-nm-thick permalloy onto large arrays of self-assembled spherical SiO2-particles with a diameter of 330 nm. The vortex...

  • 40 000 pixel arrays of ac-excited silicon microcavity plasma devices. Park, S.-J.; Chen, K.-F.; Ostrom, N. P.; Eden, J. G. // Applied Physics Letters;3/14/2005, Vol. 86 Issue 11, p111501 

    Arrays of (50 μm)2 Si microcavity plasma devices, as large as 40 000 pixels (200×200) with a packing density of 104 pixels cm-2, have been operated continuously in 500–900 Torr of Ne with ac excitation (5–20 kHz). More than two orders of magnitude larger than previously...

  • Lam, Novellus both strip wafer edges. E. K. // Solid State Technology;Oct2007, Vol. 50 Issue 10, p26 

    The article reports on the new plasma enhanced chemical vapor deposition (PECVD) tool developed by Novellus Systems Inc. and Lam Research Corp. According to reports, PECVD tool provides a new dry edge-bead removal capability into the outgoing loadlock. Using an off-the-shelf downstream plasma...

  • Real Time MHD Mode Control Using ECCD in KSTAR: Plan and Requirements. Joung, M.; Woo, M. H.; Jeong, J. H.; Hahn, S. H.; Yun, S. W.; Lee, W. R.; Bae, Y. S.; Oh, Y. K.; Kwak, J. G.; Yang, H. L.; Namkung, W.; Park, H.; Cho, M. H.; Kim, M. H.; Kim, K. J.; Na, Y. S.; Hosea, J.; Ellis, R. // AIP Conference Proceedings;2014, Vol. 1580, p506 

    For a high-performance, advanced tokamak mode in KSTAR, we have been developing a real-time control system of MHD modes such as sawtooth and Neo-classical Tearing Mode (NTM) by ECH/ECCD. The active feedback control loop will be also added to the mirror position and the real-time detection of the...


Read the Article


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

Try another library?
Sign out of this library

Other Topics