Diagnostics of Long-Term Erosion and Deposition of the Material of the First Wall in the KTM Tokamak: Testing and First Results

A diagnostic method for material transport (erosion and deposition) in the KTM tokamak vessel has been developed and tested for durations comparable to an experimental campaign. It is based on witness samples mounted in the tiles of the first wall of the tokamak vacuum vessel. It was found that the regions of greatest wall erosion are located near the equatorial plane and on the inner side of the upper dome. Deposition zones were identified on the outer periphery on the lower side of the chamber. Possible effects of conditioning and operational discharges on wall sputtering were considered.