The FAIR heavy-ion synchrotrons SIS18 and SIS100 as part of
the new FAIR accelerator facility at GSI will be operated at the
“space charge limit” for light and heavy-ion beams. In SIS100 beam
loss due to space charge induced resonance crossing should not
exceed a few percent during the 1 s injection plateau. In order to
further increase the beam intensities beyond the FAIR reference
parameters, a new concept of (partial) space charge compensation by
pulsed electron lenses is considered. We describe the general space
charge compensation concept together with detailed simulations
results. A prototype lens for SIS18 is presently under development
and will be used to validate the concept. This new approach, aiming
for mitigating the most prominent intensity limitation, should be
applicable to many of the existing large scale proton and heavy-ion
synchrotrons world wide.