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. The observations call for both a qualitative explanation and a quantitative theoretical model.
Institute for Storage Ring Facilities, University of Aarhus, DK-8000 Aarhus C, Denmark.
S P
SP
Møller
A
A
Csete
T
T
Ichioka
H
H
Knudsen
U I
UI
Uggerhøj
H H
HH
Andersen