EXPERIMENTAL-STUDY OF THE BEAM DIVERGENCE FROM A BROAD-BEAM ELECTRON-CYCLOTRON RESONANCE ION-SOURCE

Various factors affecting divergence of an ion beam extracted from a broad-beam electron cyclotron resonance ion source are studied. The source has three graphite grid extraction optics providing an 18-cm ion beam. A simple apparatus and method is used to investigate the beam divergence as a function of source pressure, magnetic field, microwave power, beam energy, and suppression voltage. We discovered that the beam divergence ranges from ±4°to ±8°. We also noticed that, considering a 10% experimental error, suppression voltage does not strongly affect the beam divergence.