THE SIZE EFFECT OF A LANGMUIR PROBE INTO FLOWING THERMAL PLASMAS

The thermal plasma conditions under a practical use could be affected by the insertion of a solid, cold probe severely. In this study, we calculated flowing thermal plasmas with two different sizes of a Langmuir probe into an argon free burning arc system and investigated the thermal and flow disturbances caused by the metallic probe. From the results, the severe disturbance of a large part of the thermal plasma, especially the axial velocity field, by the inserted probe has been found. Therefore, it might be a practical solution to use a Langmuir probe which has sufficiently small diameter for avoiding such a severe disturbance.