ELECTRON-TEMPERATURE CONTROL FOR PLASMAS PASSING THROUGH A NEGATIVELYBIASED GRID

Electron-temperature control is performed on plasmas passing through a coarse mesh grid from a discharge region. By increasing a negative po tential applied to the grid, the electron temperature is continuously decreased in a very wide range covering almost two orders of magnitude down to the value nearly equal to the background gas temperature in c ase of direct current argon or helium gas discharge. The temperature d ecrease is accompanied by an increase in the electron density. This me thod of electron-temperature control can also be applied to plasmas pr oduced by radio-frequency and electron cyclotron resonance discharges.