Possibility of plasma position detection by means of peripheral plasma potential measurements in tokamak

In the current paper a method of plasma position measurement, alternative to magnetic diagnostics, is proposed. The method is based on determination of the last closed flux surface (LCFS) location by detecting the maximum of electrostatic potential profile. The experiments were carried out on the TUMAN- 3M tokamak in a series of similar ohmic heating shots. The method proved effective in LCFS localization; it allowed calculation of corrections for magnetic diagnostics, used routinely for plasma position detection. This method can be used in limiter and divertor tokamaks for independent check and clarification of electromagnetic plasma position diagnostics.