TEMPERATURE AND ELECTRON-DENSITY MEASUREMENTS IN A HELIUM HYDROGEN CAPACITIVELY COUPLED MICROWAVE PLASMA

Various temperature and electron density measurements have been carried out in a capacitively coupled microwave plasma (CMP) with a mixture of hydrogen and helium as the plasma gas using a photodiode array spectrometer for detection. Fe I lines were used for excitation temperature, OH lines for rotational temperature and the H(beta) line for electron number density measurements. Rotational temperatures were found to be between 1800 K and 3000 K. excitation temperatures varied between 2000 K and 5000 K and electron number densities varied between 4 x 10(14) cm-3 and 9 x 10(14) cm-3, depending on operating conditions. The influence of power, observation position, solution uptake rate and carrier gas flow have been investigated.