Negative Ion Source Tests for H- Injection at the Brookhaven AGS

A magnetron ion source of Fermilab design has been adapted to provide an H- beam of 40 mA for acceleration in the Brookhaven 200 MeV Linac and injection into the AGS. The source operates at a repetition rate of 5 Hz and produces pulses of up to 250 ¿sec duration. Source stability, beam current and emittance have been studied as a function of several external source parameters. Beam emittance has been measured for two values of field gradient in the combined function magnet following the source. Evidence of neutralization of the space charge potential of the H- beam has been noted. In the focussing plane the emittance was smaller by a factor of 2 for the higher magnet gradient.