Numerical study of the effects of space charge on periodic focusing. (Etude numerique d'effets de charge d'espace en focalisation periodique)

Filamentation effects entailing emittance growth due to space charge in the transport of intense beams have been studied by numerical simulation. Programs tested on calculable cases in continuous focusing systems show for high intensities, in the case of periodic focusing and according to the periodicity, either instability-type phenomena appearing at intensities below the thresholds so far known or progressive, though slow, and regular growths of emittance, which allow more intense beams to be transported over moderate distances. At low intensities, emittances remain constant. No detailed theoretical interpretation of these results is proposed