[en] Experiments are described pertaining to the development of very high current pulsed linear ion accelerators utilizing electron neutralization. These have application as inertial fusion drivers with intermediate mass ion beams of greatest interest. Progress has been made in a number of areas. A novel magnetically insulated gap using radial magnetic fields has been tested. It provides stable electron cloud confinement over microsecond time scales with no detectable leakage current. The gap can act as an ion injector when used in conjunction with a plasma source. Control of the electron cloud dynamics allows the injector to operate in an enhanced current density mode (10 to 50 times the Child-Langmuir limit) with high efficiency and with plasma source control of the current flow. Currents up to 20 kA at 100 kV applied voltage resulted when using a light ion flashboard. Carbon beams were produced by extraction from a flowing plasma from a gun array