Hot Langmuir probe measurements in a chemically reactive plasma and accurate evaluation of the electron energy distribution function

摘要

The electron energy distribution function (EEDF) derived from Langmuir probe measurements is reported for the chemically reactive plasma of a positive column of Ar+4% CF{sub}4 DC gas discharge with a reduced electric field E/N-29 Td and gaspressure P = 150 Pa. It is shown that the electrically heated probe can be successfully applied to eliminate the deformations of the second derivative of the probe current caused by probe contamination. A method based on using an electron emitting probein second derivative measurements is introduced for substantially more accurate determination of the plasma potential. In the processing of the second derivative curve allowance was made for the influence of the finite probe radius. The obtained resultwas compared with the Maxwellian and Druyvesteyn EEDF and with our previous calculations of the Boltzmann equation.