Tornado-type closed magnetic trap for an electron cyclotron resonance ion source

We propose to use a Tornado-type closed magnetic trap for creation of a sou rce of multicharged ions with plasma heating by microwave radiation. Plasma loss in closed traps is determined by diffusion across the magnetic field, which increases substantially plasma confinement time as compared to the c lassical mirror trap. The Tornado trap also possesses merits such as: an op portunity to produce high magnetic fields up to 3 T, which makes possible h eating and confinement of plasma with a high density of electrons; an oppor tunity to use supplementary coils for ion extraction; plasma stability to m agnetohydrodynamic perturbations because the magnetic field structure corre sponds to the "min B" configuration; and relatively low costs. All estimate s and calculations were carried out for the existing Tornado-322 pulse inst allation (maximal magnetic field 2.8 T) with plasma heating at 53 GHz frequ ency. The numerical simulation has shown that, by the end of the magnetic f ield pulse, ion distribution over charge states may reach a maximum at Ar+1 6 for the plasma density of 10(13) cm(-3). The current density of ions Ar+1 6 can be varied from 10 mA/cm(2) to approximately 1 A/cm(2). (C) 2000 Ameri can Institute of Physics. [S0034-6748(00)67602-5].