  A new approach to the development of extraction systems capable of forming
ion beams with previously inaccessible intensity is proposed. The use of
inhomogeneous accelerating field allows to improve the ion beam formation
efficiency significantly. The increase of electric field magnitude is achieved
by changing the shape of the electrodes only, without increasing the
accelerating voltage and decreasing the interelectrode distance. The comparison
is made between a new extraction system and a flat traditional one, which is
the most common. The use of a new electrode geometry allows to increase the
lifetime of the electrodes in sources of intense beams operating in a
continuous wave mode. For electron cyclotron resonance ion sources, results
demonstrate the possibility to form high-quality ion beams with a current
density of more than $1\:A/cm^2$.
