Electron beam propagation in the ion-focused regime

In this paper the features of propagation of intense relativistic beams are discussed in the environment of low-density (≲1 Torr), partially ionized gas. Beam phenomena in this ion-focused regime (IFR) are found to be analogous to those at much higher density. Several instabilities and dissipative mechanisms have been identified and are compared to their high-density counterparts. Scaling laws are derived for quantitative estimation of these effects. In general, it is found that long propagation distances are possible in the laboratory suggesting that this regime may be useful for controlled beam transport and conditioning.