Fluctuation of charge in laser-induced plasmas.

Delle Side D., Giuffreda E., Buccolieri G., Monteduro L., Paladini F., Nassisi V.
  Venerdì 30/09   15:00 - 18:00   Edificio Psicologia 2 - Aula 3G   VI - Fisica applicata, Acceleratori e Beni Culturali
When a laser-induced plasma expands, it is subject to ionization and recombination phenomena. The three-body recombination is the main phenomenon leading to fluctuations in the charge that could be extracted, affecting the charge state distribution of the resulting ion beams. This problem could be overcome by a careful design of the extraction system, setting its length to a value greater than a certain critical distance, $L_{cr}$, where a sort of freezing of charges occurs and the extracted charge goes as $L^{-2}$, with $L$ being the observation distance. In practice, $L_{cr}$ is dependent on the laser wavelength.