Characterization of a plasma produced by pulsed arc using an electrostatic double probe

In this work the determination of plasma parameters of a pulsed-arc discharge by using an electrostatic double probe is presented. The system to generate the plasma is composed mainly of a reaction chamber, where the electrodes of different materials (Ti, Zr, Al) were placed in order to identify the variation of the plasma parameters when the cathode material is changed. An automatic system has been implemented for acquiring data starting from the bias of a double electrostatic probe. This system allowed registering complete curves of current-voltage in relatively short times (approximate to 30 ms). The electron density n(e) and electron temperature T-e can be extracted from the I-V characteristic curves obtained. The advantage of this technique is its facility to provide the whole quantity of "in situ" information, which can be compared with the theoretical results using numeric methods for the I-V curves simulation. By means of a suitable fit this allowed the determination of the plasma parameters. The values obtained for T, were in the order of 1 eV and for n(e) of about 10(13) cm(-3). A significant variation for n(e) was not found. (c) 2005 American Vacuum Society.