Stopping power in insulators and metals without charge exchange.

The slowing-down process of pointlike charged particles in matter has been investigated by measuring the stopping power for antiprotons in materials of qualitatively very different nature. Whereas the velocity-proportional stopping power observed for metal-like targets such as aluminum over a wide energy range of 1-50 keV is in agreement with expectations, it is surprising that the same velocity dependence is seen for a large band-gap insulator such as LiF. The validity of these observations is supported by several measurements with protons and several checks of the target properties.

Antiproton stopping at low energies: confirmation of velocity-proportional stopping power.

The stopping power for antiprotons in various solid targets has been measured in the low-energy range of 1-100 keV. In agreement with most models, in particular free-electron gas models, the stopping power is found to be proportional to the projectile velocity below the stopping-power maximum. Although a stopping power proportional to velocity has also been observed for protons, the interpretation of such measurements is difficult due to the presence of charge exchange processes.

[Surgical hand disinfektion with a solution of performic acid (author's transl)].

Disinfection with a solution of performic acid has an intensive bactericidal and sporocidal effect. This method is simple and prompt in service, is free from danger, inexpensive and can be used everywhere.