
As above, so below...indeed.
In electrodeless rf produced plasma, all electron loss must be balanced by ion loss. The steady-state loss rate of ions must balance the loss rate of electrons created by ionization because ion and electrons are created with equal rates.
What that means to me is proof that an applied external voltage potential is not necessary to create sheaths and electrostatic fields in plasma, and that "charge exchange ions" can get trapped in the sheaths and "leak" back out.The potential dip shown in Fig. 9 and Fig. 10 presents a problem in steady-state plasma. Ion-neutral charge ex
change in weakly collisional plasmas should fill up the potential dip. Charge exchange ions are electrostatically trapped in the well. The increased ion density reduces the curvature, i.e., the well depth. In steady state the dip should not exist. The solution appears to be that the potential dip seen in one direction is not a dip in the perpendicular direction, and that ions can leak out in the radial direction. The extremes of the plasma potential in rf plasma can be determined from the time-averaged emissive probe I-V characteristic curve. Peaks in the derivative dI / dV are found at maximum and minimum of the plasma potential. This is illustrated by data for a low-density inductive discharge shown in Fig. 12.23 rf is applied to a spiral coil separated from the plasma by an electrostatic screen ͑Faraday shield͒ whose area could be varied ͑see Fig. 13͒. It is apparent that the minimum plasma potential is approximately constant near 20 V while the maximum varies linearly with the open area. Data near an electrode, to which a sinusoidal voltage is applied, in a filament produced multidipole plasma, is shown in Fig. 14.24 Note that the maximum positive profile resembles the electron sheath profile including the potential dip shown in Fig. 9. The minimum potential profile resembles the ion sheath profile. Ion trapping in the potential dip is not a problem because charge exchange ions are emptied out each cycle. Overall, the characteristics of the potential dips are not understood.
Apply the concept of rf produced plasma to Anthony Peratts paper, for example, and it all fits together quite well, imo.For solution 1, each ion species is lost at its own Bohm velocity while for solution 2, all species are lost at the same velocity vs which equals the sound velocity of the system of particles.
Firstly the apparatus described would function as a Tesla System.This is illustrated by data for a low-density inductive discharge shown in Fig. 12.23 rf is applied to a spiral coil separated from the plasma by an electrostatic screen ͑Faraday shield͒ whose area could be varied ͑see Fig. 13͒. It is apparent that the minimum plasma potential is approximately constant near 20 V while the maximum varies linearly with the open area. Data near an electrode, to which a sinusoidal voltage is applied, in a filament produced multidipole plasma, is shown in Fig. 14.24 Note that the maximum positive profile resembles the electron sheath profile including the potential dip shown in Fig. 9. The minimum potential profile resembles the ion sheath profile. Ion trapping in the potential dip is not a problem because charge exchange ions are emptied out each cycle. Overall, the characteristics of the potential dips are not understood.
Something they didn't expect or "model", but discovered in the lab by experiment.The solution appears to be that the potential dip seen in one direction is not a dip in the perpendicular direction, and that ions can leak out in the radial direction.
"We believe the ribbon is a reflection," says Jacob Heerikhuisen, a NASA Heliophysics Guest Investigator from the University of Alabama in Huntsville. "It is where solar wind particles heading out into interstellar space are reflected back into the solar system by a galactic magnetic field."
Mmmmmm."If this mechanism is correct--and not everyone agrees--then the shape of the ribbon is telling us a lot about the orientation of the magnetic field in our corner of the Milky Way galaxy," notes Heerikhuisen.
Oh wow, duh! I never thought of it that way. I used to repair HF aviation radios in the Navy, and as such already knew the answer to that question!junglelord wrote:My understanding of RF and plasma is based on well understood physics of RF Propagation and methods used right now to transmitt signals via the earths upper atmosphere, as RF signals do not propagate through a plasma if the Plasma Frequency (the motion of the electrons in a plasma, termed harmonic motion) is higher then the RF.
If the RF is higher then the Plasma Frequency, then it will pass right through.
So it would depend on the Plasma Frequency and the frequency of the RF in that particular case.
Hope that helps.
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