Spark source of carbon ions

A spark carbon ion source (SIS) has been fabricated and tested with two systems of electric power supply. It was found that in the quasistationary spark (inductive energy storage scheme), and for a discharge current of ∼2 kA and timp∼100 μs, the ion charge state distribution is similar to the HF spark with a discharge current of 2 kA (1-MHz LC-circuit scheme). A total pulse carbon ion current of about 500 mA has been obtained from the quasistationary spark. The C+3 ion current was about 300 mA and the C+4 ion current ∼100 mA. The noise amplitude of the total ion current is no more than 10% in this mode of operation. The production of highly charged ions is explained by an increased potential drop in the discharge gap (60–100 V) for currents of 1.5–2.0 kA. It is shown that the quasistationary spark mode is accompanied by an occurrence of a stable anode spot while electrode evaporation increases and the vacuum spark is transformed into a high pressure spark discharge, leading to a shift of the ion spectral distribution to high charge states. The proposed spark ion source could find new applications in different accelerators along with PIG, ECR, etc.