München 2019 – wissenschaftliches Programm

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P: Fachverband Plasmaphysik

P 6: Low Pressure Plasmas I

P 6.4: Vortrag

Montag, 18. März 2019, 17:30–17:45, HS 20

The absolute calibration of an energy-selective mass spectrometer with the reference IVDF from a 1D PIC simulation of a symmetrical RF plasma — •Christian Schulze¹, Hanno Kählert², Michael Marsand², and Jan Benedikt¹ — ¹Institute of Experimental and Applied Physics, Kiel University, Germany — ²Institute of Theoretical Physics and Astrophysics, Kiel University, Germany

Energy-selective mass spectrometry (ESMS) is a broadly used diagnostic in plasma research due to its versatile applications like residual gas analysis, determination of velocity distributions of ions and neutrals as well as the identification of metastable species. Despite of its frequent use there are very few information about the main artifacts like chromatic abberation, energy dependence of the acceptance angle and mass discrimination that can strongly distort the measurement. Especially the ion lens system with its unknown transmission behavior has a crucial influence on the measured ion signal. Therefore, ESMS provides mainly qualitative information about ion fluxes.

We constructed a symmetric RF CCP setup with the ESMS sampling orifice integrated in the grounded electrode to study IVDFs of the ions that are accelerated in the sheat. The symmetry of the discharge allows for direct comparison to 1D MCC-PIC simulation. The simulation provides angular and velocity resolved absolute ion fluxes. Therefore, the comparison of measured and simulated IVDFs is used to investigate the effects of distortions and calibrate the measured ion signal to the simulated absolute ion flux.