Multiaperture negative ion source.

The long-pulse multiaperture surface-plasma source with negative ion production on a cesiated grid is under construction at Budker Institute. The ion source includes RF plasma driver, an expansion chamber with multicusp magnetic filed, an external magnetic filter and a four-electrode ion-optical system for beam extraction and acceleration. The projected parameters of the ion source are: beam current 1.5 A, beam energy 120 keV, pulse duration 100 s, RF power in plasma 40 kW, hydrogen filling pressure < 0.5 Pa, e/H- ratio 1:1, H- ions emission current density 30 mA/cm2. [ABSTRACT FROM AUTHOR]