Far-field sheaths due to fast waves incident on material boundaries

D'Ippolito, D. A.; Myra, J. R.; Jaeger, E. F.; Berry, L. A.
October 2008
Physics of Plasmas;Oct2008, Vol. 15 Issue 10, p102501
Academic Journal
The problem of “far-field” sheath formation is studied with a new quantitative one-dimensional model. These radio-frequency (rf) sheaths occur when unabsorbed fast waves in the ion cyclotron range of frequencies are incident on a conducting surface not aligned with a flux surface. Use of a nonlinear sheath boundary condition gives self-consistent solutions for the wave fields and sheath characteristics, and it introduces a sheath-plasma-wave resonance which can enhance the sheath potential. The model is used to compute the parametric dependence of the far-field sheath potential. Its application to post-process the rf fields computed by a full-wave code for a typical D(H) minority heating scenario is also discussed. This work shows that two-dimensional effects (included heuristically) are essential in determining whether far-field sheath potentials are strong enough to cause significant edge interactions, such as impurity generation and reduced heating efficiency.


Related Articles

  • Low-frequency plasma-waveguide cutoff. Eways, Saad E.; Oakes, M. E. // Physics of Fluids (00319171);Feb85, Vol. 28 Issue 2, p444 

    A new low-frequency cutoff for the m = -1 fast wave in a cold cylindrical plasma in the ioncyclotron frequency range is reported for the completely-filled plasma waveguide. The presence of a vacuum gap between the plasma and the conducting wall enables the wave to propagate to arbitrarily small...

  • Magnetic field distribution measurements in a low-pressure inductive discharge. Piejak, R.; Godyak, V.; Alexandrovich, B. // Journal of Applied Physics;11/1/1995, Vol. 78 Issue 9, p5296 

    Presents a study which measured the magnitude and relative phase of the radio frequency magnetic flux density as a function of radial position using a magnetic probe. Experimental details; Results and discussion; Conclusion.

  • Commissioning of 170 GHz, 1 MW EC H&CD in KSTAR. Jeong, J. H.; Sakamoto, K.; Joung, M.; Park, S. I.; Kim, H. J.; Han, W. S.; Kim, J. S.; Bae, Y. S.; Yang, H. L.; Kwak, J. G.; Kwon, M.; Namkung, W.; Park, H.; Cho, M. H.; Kajiwara, K.; Oda, Y.; Hosea, J.; Ellis, R.; Doane, J.; Olstad, R. // EPJ Web of Conferences;2012, Issue 32, p02019-p.1 

    The newly installed electron cyclotron heating and current drive (EC H&CD) system with a frequency of 170 GHz was successfully commissioned and used for the second-harmonic ECH-assisted startup in 2011 operational campaign of the KSTAR. As a RF power source, ITER pre-prototype of 170 GHz, 1 MW...

  • Radio frequency heating in the ion-cyclotron range of frequencies. Swanson, D. G. // Physics of Fluids (00319171);Sep85, Vol. 28 Issue 9, p2645 

    Both the theory of the absorption process in the ion-cyclotron range of frequencies and some of the experiments which slow the promise and problems with radio frequency plasma heating in this range are discussed. It is shown that mode conversion is invariably involved in the process and so an...

  • Stochastic RF Heating of Thermal Ions. Fredrickson, E. D.; Phillips, C. K.; Hosea, J.; Wilson, J. R.; Bonoli, P.; Gorelenkov, N. N.; Wright, J.; Valeo, E. // AIP Conference Proceedings;9/15/2007, Vol. 933 Issue 1, p111 

    An idea for directly heating the thermal ion population with radio frequency waves at frequencies below the ion cyclotron frequency is proposed. This method would increase fusion efficiency by avoiding the lossy electron channel

  • Magnetized microplasmas generated in a narrow quartz tube. Yoshiki, Hiroyuki // Applied Physics Letters;7/13/2009, Vol. 95 Issue 2, p021501 

    Magnetized He and Ar microplasmas in a narrow quartz tube having an inner diameter of 1 mm (referred to as magnetized capillary microplasmas) are reported. A capillary microplasma can be magnetized by the occurrence of a radio frequency (rf) oscillating E×B drift motion along the tube axis,...

  • Initial commissioning results with the NSCL Electron Beam Ion Trap. Schwarz, S.; Bollen, G.; López-Urrutia, J. R. Crespo; Kester, O.; Kittimanapun, K.; Lapierre, A.; Leitner, D.; Ottarson, J.; Portillo, M. // Review of Scientific Instruments;Feb2012, Vol. 83 Issue 2, p02A908 

    The ReA reaccelerator is being added to the National Superconducting Cyclotron Laboratory (NSCL) fragmentation facility in order to provide exotic rare-isotope beams, not available at the Isotope Separation On-Line facilities, in the several-MeV/u energy range. The first stage of the NSCL...

  • Effect of magnetic flux trapped in intergranular space on magnetic field dependences of rf... Golubnichaya, G.V.; Kirichenko, A.Ya. // Low Temperature Physics;Feb97, Vol. 23 Issue 2, p122 

    Investigates the dependences of radio frequency (rf) absorption in high temperature superconducting ceramics on a magnetic field. Proposed electrodynamic model that takes into account the magnetic flux trapping both in granules and in the intergranulae space; Explanation of all observed...

  • Investigations of Low and Moderate Harmonic Fast Wave Physics on CDX-U. Spaleta, J.; Majeski, R.; Phillips, C.K.; Dumont, R.J.; Kaita, R.; Soukhanovskii, V.; Zakharov, Z. // AIP Conference Proceedings;2003, Vol. 694 Issue 1, p213 

    Third harmonic hydrogen cyclotron fast wave heating studies are planned in the near term on CDX-U to investigate the potential for bulk ion heating. In preparation for these studies, the available RF power in CDX-U has been increased to 0.5 MW. The operating frequency of the CDX-U RF transmitter...


Read the Article


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

Try another library?
Sign out of this library

Other Topics