Energy spread and extracted current measurements are presented for five different types of ion sources: hot cathode, cold cathode, magnetron, microwave, and electron cyclotron resonance (ECR). The measurements were performed with a 45° parallel‐plate energy analyzer with a resolution of better than 0.5 eV at 500 eV incident energy. Energy spreads ranged from 0.5 to 4 eV, while total extracted beam currents ranged from 2 to 30 &mgr;A. Beam currents due specifically to protons,3He++ions, and H+2ions are also presented. The ECR and magnetron sources gave the best overall performance. These, along with the energy analyzer, are currently being used in experiments to study ion‐atom collision physics. ©1994 American Institute of Physics.