Publikace na Matematicko-fyzikální fakulta |
2014
Abstrakt
Dust grains are present on the surface of the Moon and can be charged by particles from the Sun (photons, electrons, and ions). We present laboratory measurements of photoemission from a single glass grain of micron size (a lunar analogue material).
The grain is caught in the electrodynamic trap and irradiated by UV source with distinct He I (21.2 eV) and He II (40.8 eV) lines. The grain specific charge is evaluated from the grain oscillation frequency in the electrodynamic trap.
In our measurements, we determine grain surface potential,its size, and work function from the time evolution of the charging by He I and He II photons. First results indicate that the work function of the glass grain is about 4.7 eV.