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Low-temperature plasma nitrocarburizing treatments are applied to improve the surface properties of austenitic stainless steels by forming an expanded austenite layer without impairing the excellent corrosion resistance of the steel. Here, low-temperature active screen plasma nitrocarburizing (ASPNC) was investigated in an industrial-scale cold-wall reactor to compare the effects of two active screen materials: (i) a steel active screen with the addition of methane as a gaseous carbon-containing precursor and (ii) an active screen made of carbon-fibre-reinforced carbon (CFC) as a solid carbon precursor. By using both active screen materials, ASPNC treatments at variable plasma conditions were conducted using AISI 316L. Moreover, insight into the plasma-chemical composition of the H2-N2 plasma for both active screen materials was gained by laser absorption spectroscopy (LAS) combined with optical emission spectroscopy (OES). It was found that, in the case of a CFC active screen in a biased condition, the thickness of the nitrogen-expanded austenite layer increased, while the thickness of the carbon-expanded austenite layer decreased compared to the non-biased condition, in which the nitrogen- and carbon-expanded austenite layers had comparable thicknesses. Furthermore, the crucial role of biasing the workload to produce a thick and homogeneous expanded austenite layer by using a steel active screen was validated.

The planed Facility for Ion Research (FAIR) is a new international accelerator laboratory at the GSI in Darm-stadt, Germany. The main topic at this facility is aimed to heavy ion research. The FAIR project in comparison to the existing facility GSI extends the research area by raising the energy of ion beams. After creation of the ion beam at the ion source the state charge is low. Therefor the demand for acceleration of the beam to the highest possible energy is a highly ionized charge state of the beam. For beam stripping to get higher charge state, the traditional tools are gas stripper and foil stripper [1, 2]. Hence Plasma is suggested to be a stripper medium. In Frankfurt are different kinds of Pinch Plasmas under investigation for Stripper. The constricting effect on the plasma or conductor is produced by the magnetic field pressure resulting from the current or by the Lorentz force produced by the current flowing in its own magnetic field. In addition to separate the high pressure discharge cham-ber of the accelerator a plasma window will be used [3]. This contribution gives an overview of the plasma proper-ties and shows first results of different beam times at the GSI., Proceedings of the 7th Int. Particle Accelerator Conf., IPAC2016, Busan, Korea