Moving double probe measurements in copper arc plasma and derivation of plasma parameters

Summary form only given. A moving single probe technique has a reference point since it is biased with reference to any one electrodes of the plasma producing system. However, in some situations such as RF discharges and ionospheric plasma, a reference point is not available to bias the moving single probe. Hence a single moving probe technique is not applicable in such situations and the moving double probe technique is found to be more appropriate. Each probe is biased with respect to the other in this technique. When the two probes in a vertical plane are biased with a potential and allowed to move through arc plasma, collect some charges depending on the magnitude of the biasing potential, geometry of the probes and the time of flight of the probes. Charge collected by the probe hence current flowing to the probe circuit is estimated. The electron temperature, ion density, floating potential and the thermal velocity of ions are estimated. In the present investigations the copper arc current is maintained constant and the arc gaps are varied. It is expected that the electron temperature, ion density and thermal velocity be expected to be the same for all these different arc gaps. The derived results are based on probe measurements supports that the plasma parameters do not depend upon the arc gap, but depends on the arc current.