Are Interaction-free Measurements Interaction Free?

In 1993 Elitzur and Vaidman introduced the concept of interaction-free measurements which allowed finding objects without ``touching'' them. In the proposed method, since the objects were not touched even by photons, thus, the interaction-free measurements can be called as ``seeing in the dark''. Since then several experiments have been successfully performed and various modifications were suggested. Recently, however, the validity of the term ``interaction-free'' has been questioned. The criticism of the name is briefly reviewed and the meaning of the interaction-free measurements is clarified.Comment: 11 pages, 3 eps figures. Contribution to the ICQO 2000, Raubichi, Belaru

New facility for simultaneous implantation and evaporation

The Groningen isotope separator has been extended with a double uhv evaporation system. Implantation and evaporation can now be done at the same time under good vacuum conditions. Implanted systems with thicknesses up to 6.3 μm have been produced

Isolated tin fluoride molecules in a copper lattice

A Mössbauer absorber was made by simultaneous evaporation of copper and implantation of119Sn, and postimplantation of F. A large fraction of Sn4+ was formed, assigned to the formation of SnF4

Simulation of Ion-Beam Channeling in Icosahedral Al63Cu25Fe12

Monte Carlo simulations of channeling on the icosahedral quasicrystal Al63Cu25Fe12 were made, using an experimentally determined structure model for this phase. The channeling effect was found to be nearly as good as for a normal, periodic crystal. Dip widths are in agreement with experimental values, but minimum yields are not. The minimum yield is inversely proportional to the beam energy at low energy. Future experiments to be done are proton-induced-x-ray-channeling experiments and Rutherford-backscattering-channeling experiments at low energy