A Freeman type ion source designed for ion implanter is described. The ion source is simple

low consumption and cheap in price. After improving the structure of discharge chamber and extracting system

high quality para-axial ion beam of 0.5—1mA can be obtained. Conventional two slits method is used for measurements of beam emittance. The energy normalized emittance is 2—4×10

-5

mm·rad·MeV

1/2

and normalized brightness≥7.6×10

10

A/m

2

·rad·This ion source is suitable for practical uses.