  Ion source modification is proposed for efficient production of ion beam and
extending of operating Lifetime. Ionization efficiency of the Bernas type ion
source has been improved by using a small anode-thin rod, oriented along the
magnetic field. The transverse electric field of small anode transport plasma
by drift in crossed field to the emission slit. Optimization of the cathode
material recycling is used to increase the operating lifetime. Optimization of
the wall potential is used for suppression of flakes formation. A
three-electrode extraction system was optimized for low energy beam production
and efficient space charge neutralization. An ion beam with emission current
density up to 60 mA/cm2 has been extracted from discharge in BF3 gas.
