Method and apparatus for stabilizing of the glow plasma discharges

Abstract

A method and apparatus for stabilizing glow plasma discharges by suppressing the transition from glow-to-arc includes a perforated dielectric plate having an upper surface and a lower surface and a plurality of holes extending therethrough. The perforated dielectric plate is positioned over the cathode. Each of the holes acts as a separate active current limiting micro-channel that prevents the overall current density from increasing above the threshold for the glow-to-arc transition. This allows for a stable glow discharge to be maintained for a wide range of operating pressures (up to atmospheric pressures) and in a wide range of electric fields include DC and RF fields of varying strength.

1 - 10 . (canceled)  
   
   
       11 . An apparatus for generating and maintaining a glow plasma discharge at atmospheric pressure, comprising: 
 a pair of electrodes positioned in facing relation having a space therebetween;    a dielectric layer having a bottom side and a plurality of recesses positioned over one of the electrodes, each of the recesses defined by a bottom wall and side walls, wherein the dielectric layer has a thickness between the bottom walls of each of the plurality of the plurality of recesses and the bottom side of the dielectric layer on the order of microns for regulating energy available to the glow plasma discharge; and    an electric field generated between the electrodes.    
   
   
       12 . The apparatus of  claim 11  wherein each of the plurality of recesses are of micron dimension.  
   
   
       13 . The apparatus of  claim 11 , wherein each of the plurality of recesses limits current density from increasing above a glow-to-arc transition threshold.  
   
   
       14 . The apparatus of  claim 11 , further comprising a second dielectric layer positioned over the other of the electrodes.  
   
   
       15 . The apparatus of  claim 14 , wherein the second dielectric layer includes a plurality of recesses, each of the plurality of recesses defined by a bottom wall and side walls, wherein the second dielectric layer has a thickness between the bottom walls of each of the plurality of the plurality of recesses and the bottom side of the second dielectric layer on the order of microns for regulating energy available to the glow plasma discharge.  
   
   
       16 . The apparatus of  claim 15 , wherein each of the each of the plurality of recesses of the second dielectric layer are of micron dimension.  
   
   
       17 . The apparatus of  claim 15 , wherein each of the plurality of recesses of the second dielectric layer limits current density from increasing above a glow-to-arc transition threshold.  
   
   
       18 . The apparatus of  claim 11 , further comprising a retaining collar for retaining the dielectric layer to one of the electrodes.  
   
   
       19 . A method for stabilizing a glow-to-arc transition for a discharge plasma at atmospheric pressures, comprising the steps of: 
 positioning electrodes in a facing relation;    providing a dielectric having a plurality of recesses, each of the recesses defined by a bottom wall and side walls, wherein the dielectric layer has a thickness between the bottom walls of each of the plurality of the plurality of recesses and the bottom side of the dielectric layer on the order of microns for regulating energy available to the glow plasma discharge;    covering one of the electrodes with the dielectric; and    generating an electric field between the electrodes.    
   
   
       20 . The method of  claim 19 , wherein the step of providing the dielectric comprises providing a dielectric having a plurality of recesses of micron dimension.  
   
   
       21 . The method of  claim 19 , further comprising providing a second dielectric having a plurality of recesses, each of the recesses defined by a bottom wall and side walls, wherein the second dielectric layer has a thickness between the bottom walls of each of the plurality of the plurality of recesses and the bottom side of the second dielectric layer on the order of microns for regulating energy available to the glow plasma discharge.  
   
   
       22 . The method of  claim 21 , wherein the step of providing the second dielectric comprises providing a second dielectric having a plurality of recesses of micron dimension.  
   
   
       23 . The method of  claim 21 , further comprising covering the other of the electrodes with the second dielectric.  
   
   
       24 . The method of  claim 19 , further comprising retaining the dielectric to one of the electrodes with a retaining collar.