A NEW APPROACH TO ION-BEAM MODIFICATION OF POWDERS

A new apparatus is presented for modifying powder particles by means o f an ion beam. This device is a concrete mixer-like rotating drum in w hich powder is agitated in order to provide both direct implantation o f ions and sputter deposition of material from a sputter foil mounted inside the drum. Online current measurements of both the implantation and the sputter current is possible. Experiments with different ion be ams, different doses, and different energies were carried out. The mod ified powders were investigated by means of atomic absorption spectros copy, neutron activation analysis, BET surface measurements, and scann ing electron microscopy with an electron microprobe. The results are c ompared with theoretical considerations.