Dependence of emittance of the He+ beam extracted from a Penning ion source on the design of the source, a Particle-In-Cell simulation

The dependence of the emittance of He+ beam extracted from a cold cathode Penning ion source on source discharge voltage, anode length, and cathode to anode distance was studied. The 2D3V particle-in-cell Monte Carlo simulation technique was utilized to perform the analysis. Different dimensions for components of the ion source such as anode length and cathode to anode distance were considered. The increase in the cathode to anode distance led to a reduction in rms emittance, almost independent of discharge voltage. This study indicated that the rms emittance slightly improves on increasing the anode length.