Using numerical simulations to extract parameters of toroidal electron plasmas from experimental data

Ha, B. N.; Stoneking, M. R.; Marler, J. P.
March 2009
Physics of Plasmas;Mar2009, Vol. 16 Issue 3, p032110
Academic Journal
Measurements of the image charge induced on electrodes provide the primary means of diagnosing plasmas in the Lawrence Non-neutral Torus II (LNT II) [Phys. Rev. Lett. 100, 155001 (2008)]. Therefore, it is necessary to develop techniques that determine characteristics of the electron plasma from features of the induced image charge signal. This paper presents a numerical study which finds that the frequency of the image charge signal due to the toroidal version of the m=1 diocotron mode is proportional to the total trapped charge and inversely proportional to magnetic field strength, as in the cylindrical case. In the toroidal case, additional information about the m=1 motion of the plasma can be obtained by analysis of the image charge signal amplitude and shape. Finally, results from the numerical simulations are compared to experimental data from the LNT II and plasma characteristics are reported.


Related Articles

  • Vacuum Arc Plasma Motion In A Curvilinear Magnetic Field In A Framework Of The Rigid-Rotor Model. Timoshenko, Aleksandr I.; Gnybida, Mikhail V.; Taran, Valeriy S.; Tereshin, Vladimir I.; Chechel'nitskij, Oleg G. // AIP Conference Proceedings;2006, Vol. 812 Issue 1, p363 

    Vacuum-arc plasma motion in a toroidal magnetic field is described on a base of steady-state (∂ / ∂t = 0) Vlasov-Maxwell equations for the long plasma column aligned parallel to a constant axial magnetic field. The relations for the self-consistent electric field, which appears due...

  • Hot electron plasmas trapped in helical magnetic surfaces. Himura, H.; Wakabayashi, H.; Yamamoto, Y.; Sanpei, A.; Masamune, S.; Isobe, M.; Okamura, S.; Matsuoka, K. // Hyperfine Interactions;Dec2006, Vol. 174 Issue 1-3, p83 

    Experimental studies on nonneutral (pure electron) plasmas of finite temperature, trapped in helical closed magnetic surfaces have been conducted. The helical electron plasmas are produced with thermal electrons launched from the outside of the last closed flux surface (LCFS). About 150 μs...

  • Modification of Δ′ by magnetic feedback and kinetic effects. Liu, Yueqiang; Hastie, R. J.; Hender, T. C. // Physics of Plasmas;Sep2012, Vol. 19 Issue 9, p092510 

    Two possible ways of modifying the linear tearing mode index, by active magnetic feedback and by drift kinetic effects of deeply trapped particles, are analytically investigated. Magnetic feedback schemes, studied in this work, are found generally stabilizing for Δ′. The drift kinetic...

  • Chaos generated pinch effect in toroidal confinement devices. Spizzo, G.; White, R. B.; Cappello, S. // Physics of Plasmas;Oct2007, Vol. 14 Issue 10, p102310 

    Particle transport in a toroidal plasma confinement device is shown to be nondiffusive when magnetic chaos is present. A phenomenological fit to density profiles gives a diffusion constant and also a pinch velocity directed up the density gradient. We show that the combination of diffusion and...

  • Electron Plasmas in a Small Aspect Ratio Toroidal Experiment. Pahari, S.; Ramachandran, H. S.; John, P. I.; Ganesh, R. // AIP Conference Proceedings;2006, Vol. 862 Issue 1, p78 

    Unlike their cylindrical counterparts, electron plasmas confined by purely toroidal magnetic fields have been marred with issues related to poor confinement times. Open particle trajectories due to inherent grad-B and curvature drifts lead to particle losses faster than the time taken for...

  • General formulation of the resistive wall mode coupling equations. Pustovitov, V. D. // Physics of Plasmas;Jul2008, Vol. 15 Issue 7, p072501 

    A theoretical framework to describe the magnetic coupling of the toroidal plasma with the resistive wall and other sources of the field asymmetry is formulated. This is done for general toroidal geometry without restrictions on the plasma, while the wall is considered as a thin shell....

  • Boost of plasma current with active magnetic field shaping coils in rotamak discharges. Yang, Xiaokang; Goss, Jermain; Kalaria, Dhara; Huang, Tian Sen // Physics of Plasmas;Aug2011, Vol. 18 Issue 8, p080703 

    A set of magnetic shaping coils is installed on the Prairie View (PV) rotamak for the study of active plasma shape control in the regimes with and without toroidal field (TF). In the spherical tokamak regime (with TF), plasma current Ip can be boosted by 200% when all five shaping coils...

  • Blob-induced toroidal momentum transport in simple magnetized plasmas. Labit, B.; Theiler, C.; Fasoli, A.; Furno, I.; Ricci, P. // Physics of Plasmas;Mar2011, Vol. 18 Issue 3, p032308 

    The link between toroidal flows and density blobs is experimentally demonstrated in TORPEX simple magnetized plasmas: momentum is transferred from an ideal-interchange mode to density blobs. The phase shift between the toroidal flow and the density perturbations observed in the interchange mode...

  • Scrape-off layer flows in the Tore Supra tokamak. Gunn, J. P.; Boucher, C.; Dionne, M.; Euran, I.; Fuchs, V.; Loarer, T.; Pánek, R.; Saint-Laurent, F.; Stöckel, J.; Adámek, J.; Bucalossi, J.; Dejarnac, R.; Devynck, P.; Hertout, P.; Hron, M.; Moreau, P.; Nanobashvili, I.; Rimini, F.; Sarkissian, A. // AIP Conference Proceedings;2006, Vol. 812 Issue 1, p27 

    Near-sonic parallel flows are systematically observed in the scrape-off layer (SOL) of the limiter tokamak Tore Supra, as in many X-point divertor tokamaks. The poloidal variation of the Mach number of the parallel flow has been measured by moving the contact point of a small circular plasma...


Read the Article


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

Try another library?
Sign out of this library

Other Topics