Dust capture experiment in HT-7

A dust capture experiment was conducted in HT-7, a medium-sized superconducting tokamak of the Chinese Academy of Sciences. An aerogel was used to intercept fast particles propagating along the ion flow. The particles produced sizable impact craters, which were characterized and measured using 3D computer tomography and a seed growing algorithm. Captured particles were also photographed and measured. This allowed the determination of average impact yields, which were approximately more than four times the particle (projectile) mass. We provide evidence that the particle velocities may reach the hypervelocity regime, i.e. v(p) >= O(1 km s(-1)).