An instrument for direct measurements of sputtering related momentum transfer to targets

The article presents an instrument that measures sputtering related momentum transfer to a target. The instrument is operated in the beam of a broad-beam ion source and its main part is similar to a rotor of a wind mill. One component of the transferred momentum perpendicular to the beam is converted into a rotational movement of its rotor. This geometry makes the device sensitive to the momentum of sputtered target atoms and reflected beam particles, but insensitive for the momentum of the impinging particles itself. Exemplary measurements with argon ions in the energy range from 0.5 keV to 1.5 keV impinging onto copper targets at an incidence angle of 56° are presented. The results are compared with simulations based on the popular Monte-Carlo program TRIM and show a good agreement.