Production of Doubly Charged Ions Using a Hollow Cathode Ion Source with an Evaporator

The paper describes the production of doubly charged ions from solids and gases using a hollow cathode ion source with an internal evaporator heated by a spiral cathode filament and arc discharge. The obtained currents were 15 μA for $Bi^{2+}$, 10 μA for $As^{2+}$ and $Al^{2+}$, 8 μA for $Kr^{2+}$ and $Xe^{2+}$, 5 μA for $In^{2+}$ and $Ge^{2+}$, enabling moderate dose implantations ( ≈ $10^{15} cm^{-3}$) with doubly charged ions. Characteristics of the ion source are presented and discussed in order to choose the optimal working parameters. A brief presentation of numerical model of doubly and singly charged ions in the ion source is given. The calculated results (dependences of ion current on the anode voltage) are in good agreement with the experimental data.