During experiments with our laser-ion source [G. Korschinek and J. Sellmair, Nucl. Instr. and Meth. A243 (1986) 260; J. Sellmair and G. Korschinek, Nucl. Instr. and Meth. A278 (1989) 651] we were able to achieve charge states up to 21 + for Ta. We have also shown the importance of long laser pulses at the same power. The influence of background pressure is of no importance up to a level of approximately 10(-5) mbar. Studies have been performed to compensate for the space charges by active electron injection and also by applying a radial image-charge field with the help of an axial wire. In both cases remarkable enhancements of the currents were achieved.