Experimental Characterization of an Overdense Plasma in a Compact Ion Source

Abstract

Abstract. Electron Cyclotron Resonance Ion Sources (ECRIS) are compact plasma-based machines able to feed particle accelerators with high intensity beams of multi-charged ions. ECRIS plasmas are density-limited, since they are sustained by E.M. wave propagation up to a cut-off density value. In the past, the only way to improve ECRIS performance was to increase the microwave frequency and the magnetic field strength to satisfy the ECR condition. A different plasma heating mechanism is being applied at INFN-LNS. It is based on Electron Bernstein Waves (EBW), i.e., electrostatic waves which do not suffer any density cut-off. Highlights concerning preliminary signatures of EBW formation and subsequent absorption are given here.

A new interferometric/polarimetric setup for plasma density measurements in compact microwave-based Ion Sources

“…O.E.S. and X-ray imaging, see also [11,12]), we performed some simulations assuming point-like emission from one of the two antennas, then exploring the propagation of the "rays" under different conditions of plasma density, normalized to the cutoff one at the pumping wave frequency (3.75 GHz).…”