The use of both a small discharge volume and magnetic mirror fields allow sequential ionization and an increased efficiency of this ion source. The extracted ion current can reach 12 mA at an extraction voltage=3 kV and discharge pressure=20 mTorr. In this paper a description of the techniques which are used for measuring the important parameters to evaluate this ion source is presented. These parameters are: beam profile, beam emittance, energy spread, and charge spectra of the beam. The source is found to have a beam emittance of 150 mm m rad, and energy spread of 30–60 eV, and a content of Ar+4reaching &bartil;20% of the total extracted ion current. ©1995 American Institute of Physics.