High current iron-free pulsed quadrupole lenses

Quadrupole lenses are built to focus ions or to transfer them between synchrotrons. In this paper we consider a way of final focusing in which certain bunches of ions are chosen. This case allows us using pulsed applications. Beside very short pulse duration of a few 10μsec and a repetition rate of only a few hertz, a very high and constant magnetic gradient is needed. To reach around 80T/m saturating iron cores are avoided and the current pulse has to be set up to 400kA for an aperture of 96mm diameter. Challenges like a stable construction, pulse forming system and adequate magnetic shielding have to be resolved.