A spectroscopic method to determine the electron temperature of an argon surface wave sustained plasmas using a collision radiative model

Abstract

A method is presented to det. the electron temp. in a low pressure Ar plasma using emission spectroscopic measurements and a collisional radiative (CR) model. Abs. line intensity measurements were made to construct the at. state distribution function. In addn. to the excited states, the ground state d. is also taken into account. Because of this, the excitation temp. can be detd. with high precision. A CR-model was used to det. the degree of equil. departure and to obtain the relationship between the excitation temp. and the electron temp. This method is applied to a microwave plasma which was generated inside a quartz tube using a surfatron device. The densities of argon levels close to the continuum are used to get an estd. value of the electron d. These values are used as input data for the CR-model. For an Ar pressure of 6 mbar, the 4p level densities vary between 8 * 1014 and 6 * 1015 m-3. Using the estd. values for the electron d., between 2 * 1019 m-3, the electron temp. was found to range between 1.15-1.20 eV. An extensive error anal. showed that the relative error in the electron temp. is