Tokamak Dust Particle Size and Surface Area Measurement

The INEEL has analyzed a variety of dust samples from operating experimental tokamaks: General Atomics' DIII-D, Massachusetts Institute of Technology's Alcator CMOD, and Princeton's TFTR. These dust samples were collected and analyzed because of the importance of dust to the safety of future fusion power plants and ITER. The dust may contain tritium, be activated, be chemically toxic, and chemically reactive. The INEEL has carried out numerous characterization procedures on the samples yielding information useful both to tokamak designers and to safety researchers. Two different methods were used for particle characterization: optical microscopy (count based) and laser based volumetric diffraction (mass based). Surface area of the dust samples was measured using Brunauer, Emmett, and Teller, BET¹, a gas adsorption technique.

The purpose of this paper is to present the correlation between our particle size measurements and our surface area measurements for tokamak dust.