Negative hydrogen ion source research and beam parameters for accelerators

H- beams are useful for multi-turn charge-exchange stripping injection into circular accelerators. Studies on a modified ion source for this purpose are presented. This paper includes some theory about a H- magnetron discharge, ion-electron emission, emittance and problems linked with emittance measurement and calculations. Investigated parameters of the emittance probe for optimal performance give a screen voltage of 150 V and a probe step of about 5 mil. Normalized 90% emittance obtained for this H- source is 0.22 π mm-mr, for an extraction voltage of 18 kV at a beam energy of 30 keV and a beam current of 11 mA