Endoscope Emulator Test Bench for ITER Dust Monitor Diagnostic

A technique based on a flexible endoscope was selected as a tool for the diagnostic of dust in ITER (“The Way” in Latin). The diagnostic will consist of two tools-one for fine viewing of dust with a resolution down to a few tens of microns in a few millimeter spot and another one for dust collection. The endoscope will have to go up to 15-m deep inside the tokamak to the inspection region. Due to the specific design features of ITER, the endoscope will have to go upward on an inclined surface for inspection about 18 m away from the insertion point. In order to ensure that the endoscope gets to the desired region of inspection, it will be pushed through guide tubes having a number of bends along their length. Initial estimations of endoscope jacket materials, endoscope stiffness, and push/pull forces were defined experimentally. This article will give a brief reminder of the overall strategy for dust/erosion/tritium monitoring in ITER that is a Protection Important Activity (PIA) and the role of the dust monitor in this context. It focuses on experimental results of real-size tests inside guide tubes of the behavior of different endoscope emulators under various conditions.