Focusing and control of multiaperture ion beams by plasma lenses

The characteristics of focusing and control of well-formed low-divergence multiaperture ion beams by a plasma lens (PL) are investigated. It is shown that spherical aberrations introduced by the departure of the radial electric potential profile from parabolic, significantly influence the focusing within the PL volume. It is established that consistent use of theoretical plasma optics principles allows the reduction of spherical aberrations and evaluation of the maximum density of the beam focused. It is shown experimentally and theoretically that the controlled introduction of spherical aberrations permits control of the radial beam profile at the target and, in particular, of the beam homogeneity.>