Experiments on hot power ion beam transport in a longitudinal homogeneous magnetic fields

Power ion beam transport is the necessary element of works, related to the beam application and production, in particular, for plasma heating, targets controlled fusion, instrument hardening etc. Results of experimental investigation into the transport of ion beam with 1-2 kA current, 400 keV ion energy and 80 ns duration in vacuum in the longitudinal magnetic field are presented. The ion beam was generated in a reflective triode and directed to virtual cathode. It is shown, that the transport character depends on the presence of the grounded grid at the inlet to the drift tube. On the whole, the charge-neutralized ion beam is filamented into three zones due to grid absence: axial one-in-side the beam hollow with a positive potential at the level of ≤ 0.1 ΦA; ring zone, reneutralized by fast electrons with a negative potential at the level of ≤ (0.01-0.05) ΦA and external zone with charge neutralization degree, being close to one. It is shown, that the zone, reneutralized by electrons, produces a focusing effect on the beam and facilitates to its more effective transport