Control of limiting currents of two charged-particle beams in coaxial drift tube

The dependence of limiting currents of two concentric magnetically-confined annular charged-particle beams on non-zero bias voltage applied to the inner conductor of a coaxial drift tube is studied. We show that the control over the limiting currents on the level up to 15 per cent for electron beams can be achieved with the inner conductor bias voltage not greater than 50 kV.