Die AMEMIYA-Sonde; Theoretischer Hitergrund

Belitz, H. J.*; Althausen, B.*; Uehara, Kazuya; Amemiya, Hiroshi*

This probe has been developed to measure the ion temperature in the scrape-off-layer (SOL) of the tokamak boundary plasma. Since in the SOL plasma the ion temperature is usually larger than the electron temperature ions reach to the probe with the thermal speed without considering presheeth at the probe frontier. The probe with the cylindrical shape is placed at the parallel to the magnetic field lines. Important parameters of this probe are probe length L, the ratio of L to the radius a and the mean ion Larmor radius r. The ion current density to the side and the end is double integrated and k is expressed analytically. When two probes with different length are placed to the parallel to the magnetic field k is estimated by the difference of the current and we can measure the temperature directly. The application examples to the SOL plasma of JFT-2M and TEXTOR are shown.