  The University of Maryland Electron Ring (UMER) has operated traditionally in
the regime of strong space-charge dominated beam transport, but small-current
beams are desirable to significantly reduce the direct (incoherent)
space-charge tune shift as well as the tune depression. This regime is of
interest to model space-charge effects in large proton and ion rings similar to
those used in nuclear physics and spallation neutron sources, and also for
nonlinear dynamics studies of lattices inspired on the Integrable Optics Test
Accelerator (IOTA). We review the definition of space-charge intensity, show a
comparison of space-charge parameters in UMER and other machines, and discuss a
simple method involving double collimation and solenoid focusing for varying
the space-charge intensity of the beam injected into UMER.
