Langmuir probe data analysis including the multi-component multiply charged nature of electron cyclotron resonance ion source plasma

Though Langmuir probes have already proved useful in the field of local plasma diagnostics, the electron cyclotron resonance (ECR) plasma, which is still poorly understood, remained an unexplored one from this point of view. To do the first step, a diagnostics setup (controlled Langmuir probe, bipolar power supply) has been built at the 14.5 GHz ATOMKI-electron cyclotron resonance ion source (ECRIS). Measurements of the cold plasma regions are reported. A modified version of the original methods for characteristics analysis, is also reported. This takes into account the complex nature of the plasma ion component. Depending on the charge state which is optimized for extraction, differences of the calculated electron densities yielded by the two compared theoretical models up to a factor of three were observed which obviously shows the necessary consideration of this effect. The presented work prepares the way for hot plasma region measurements. [Copyright &y& Elsevier]