# A Kinetic Approach to the Study of Ideal Multipole Resonance Probe

Junbo Gong, Sebastian Wilczek, Daniel Szeremley, Jens Oberrath, Denis Eremin, Wladislaw Dobrygin, Christian Schilling, Michael Friedrichs, Ralf Peter Brinkmann

WELTPP-18, December 3-4, 2015 at Rolduc, Kerkrade, the Netherlands

## Abstract

The term Active plasma resonance spectroscopy (APRS) is a well known plasma diagnostic method which utilize the natural ability of plasmas to resonate on or near the electron plasma frequency. The idea of APRS is to couple a RF signal into the plasma via a probe and to measure the response of the signal in a certain frequency range. Absorption peaks are identified where electrons resonate. Then a specific mathematical model is used to determine some important plasma parameters such as electron density or electron temperature. Based on APRS, an economical and industry compatible plasma diagnostic device has been proposed, which is so-called Multipole Resonance Probe (MRP). The Ideal MRP is a geometrically simplified version of that probe, which consists of two dielectrically shielded, hemispherical electrodes. To understand the behavior of this probe in low pressure regime, the spectral kinetic scheme is presented which enables a kinetic simulation of the interaction of the probe with the plasma. It contains of two modules, particle pusher and field solver. The particle pusher integrates the equations of motion for the studied particle ensemble over a suitable time interval. The field solver, unlike the well-known particle-in-cell (PIC), determines the electric field at each particle position without employing the numerical gird. The presented method is expected to cover the limitation of the cold plasma model.