Ion heating and short wavelength fluctuations in a helicon plasma source

Scime, E. E.; Carr, J.; Galante, M.; Magee, R. M.; Hardin, R.
March 2013
Physics of Plasmas;Mar2013, Vol. 20 Issue 3, p032103
Academic Journal
For typical helicon source parameters, the driving antenna can couple to two plasma modes; the weakly damped 'helicon' wave, and the strongly damped, short wavelength, slow wave. Here, we present direct measurements, obtained with two different techniques, of few hundred kHz, short wavelength fluctuations that are parametrically driven by the primary antenna and localized to the edge of the plasma. The short wavelength fluctuations appear for plasma source parameters such that the driving frequency is approximately equal to the lower hybrid frequency. Measurements of the steady-state ion temperature and fluctuation amplitude radial profiles suggest that the anomalously high ion temperatures observed at the edge of helicon sources result from damping of the short wavelength fluctuations. Additional measurements of the time evolution of the ion temperature and fluctuation profiles in pulsed helicon source plasmas support the same conclusion.


Related Articles

  • Asymptotic Analysis of the Whistler Waves Propagation in Space Plasma Thrusters. Melazzi, D.; Cardinali, A.; Manente, M.; Pavarin, D. // PIERS Proceedings;Aug2013, p89 

    We present a three-dimensional Ray-Tracing solver, called RAYWh (RAY-tracing Whistler), for the electromagnetic propagation and power deposition in plasma sources for space thrusters, where high density plasmas (ranging from 1017 to 1019 particles/m³) are confined by general magnetic...

  • Characteristics of a large volume, helicon plasma source. Shinohara, Shunjiro; Tanikawa, Takao // Physics of Plasmas;Apr2005, Vol. 12 Issue 4, p044502 

    A high-density helicon plasma source with very large volume, 75 cm in diameter and 486 cm in axial length, has been developed, and its characteristics have been investigated. Furthermore, the radial density profile control has been successfully demonstrated by utilizing two techniques: (1) by...

  • Spatial distribution of the RF power absorbed in a helicon plasma source. Aleksenko, O.; Miroshnichenko, V.; Mordik, S. // Plasma Physics Reports;Aug2014, Vol. 40 Issue 8, p665 

    The spatial distributions of the RF power absorbed by plasma electrons in an ion source operating in the helicon mode (ω < ω < ω < ω) are studied numerically by using a simplified model of an RF plasma source in an external uniform magnetic field. The parameters of the source...

  • Experimental observation of left polarized wave absorption near electron cyclotron resonance frequency in helicon antenna produced plasma. Barada, Kshitish K.; Chattopadhyay, P. K.; Ghosh, J.; Kumar, Sunil; Saxena, Y. C. // Physics of Plasmas;Jan2013, Vol. 20 Issue 1, p012123 

    Asymmetry in density peaks on either side of an m = +1 half helical antenna is observed both in terms of peak position and its magnitude with respect to magnetic field variation in a linear helicon plasma device [Barada et al., Rev. Sci. Instrum. 83, 063501 (2012)]. The plasma is produced by...

  • Simulation and laboratory validation of magnetic nozzle effects for the high power helicon thruster. Winglee, R.; Ziemba, T.; Giersch, L.; Prager, J.; Carscadden, J.; Roberson, B. R. // Physics of Plasmas;Jun2007, Vol. 14 Issue 6, p063501 

    The efficiency of a plasma thruster can be improved if the plasma stream can be highly focused, so that there is maximum conversion of thermal energy to the directed energy. Such focusing can be potentially achieved through the use of magnetic nozzles, but this introduces the potential problem...

  • Measurements of neutral helium density in helicon plasmas. Houshmandyar, Saeid; Sears, Stephanie H.; Thakur, Saikat Chakraborty; Carr, Jerry; Galante, Matthew E.; Scime, Earl E. // Review of Scientific Instruments;Oct2010, Vol. 81 Issue 10, p10D704 

    Laser-induced-fluorescence (LIF) is used to measure the density of helium atoms in a helicon plasma source. For a pump wavelength of 587.725 nm (vacuum) and laser injection along the magnetic field, the LIF signal exhibits a signal decrease at the Doppler shifted central wavelength. The drop in...

  • Erratum.  // International Journal of Antennas & Propagation;2014, p1 

    No abstract available.

  • Detection and evaluation of the depth of surface cracks in conductive materials by using a loop antenna. Yagi, K.; Sato, N.; Sato, Y.; Tamakawa, K.; Minkov, D.; Shoji, T. // Applied Physics A: Materials Science & Processing;2003, Vol. 77 Issue 3/4, p461 

    A new method is developed for detection and evaluation of the depth of surface cracks in conductive materials. The main components of the measurement equipment are a conductive wire and a loop antenna, both of which are located as close as possible to the surface of the investigated material,...

  • Fiber-coupled antennas for ultrafast coherent terahertz spectroscopy in low temperatures and high magnetic fields. Crooker, S. A. // Review of Scientific Instruments;Sep2002, Vol. 73 Issue 9, p3258 

    For the purposes of measuring the high-frequency complex conductivity of correlated-electron materials at low temperatures and high magnetic fields, a method is introduced for performing coherent time-domain terahertz spectroscopy directly in the cryogenic bore of existing dc and pulsed magnets....


Read the Article


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

Try another library?
Sign out of this library

Other Topics