ABSTRACT
A magnetic –eld superimposed on an electrode surface used in direct current (DC) discharge changes the distribution pro–les of electron temperature, Te, and electron density, Ne, which means that the electric discharge with magnetic –eld is different from that without a magnetic –eld [1,2]. Pro–les for DC discharge of Ar without magnetic –eld (a plain cathode plate against a plain anode plate) are shown in Figure 6.1. Electron temperature reaches the maximum value and starts to decrease sharply with further increase of distance from the cathode surface. The maximum point corresponds to where the intense glow develops at the edge of the cathode fall dark space. Electron density, on the other hand, is low, while electrons are being accelerated, and the product of Te * Ne remains nearly constant in the entire domain where meas ure ments are made, which is reasonable because the energy transferred to the gas phase is a constant. Those values are, of course, dependent on the operation factors that in˜uence the breakdown process (i.e., separation distance, surface area of electrode, system pressure, and type of gas as described in Chapter 5).
