Development of a High-Current Helicon Ion Source With High Monatomic Fraction for the Application of Neutron Generators

A D–D neutron generator using a titanium drive-in target

“…The first factor was the monatomic fraction of the deuteron beam. In a previous study on the ion source, a proton beam with a high monatomic fraction of 94% was produced [13]. On the other hand, the monatomic fraction of the deuteron beam was degraded during the test-runs because the operation of the ion source was not feasible in the same high RF-power region due to the instability of plasma.…”

“…On the other hand, the monatomic fraction of the deuteron beam was degraded during the test-runs because the operation of the ion source was not feasible in the same high RF-power region due to the instability of plasma. Considering the main atomic reactions in the plasma, it was estimated that the monatomic fraction of the beams must not exceed 60% [13]. According to the work by Kim [6], the neutron generation rate would be reduced by 30% if a deuteron beam composed of 60% D þ 1 and 40% D þ 2 ions instead of a 100% monatomic deuteron beam were irradiated on a uniform titanium deuteride target.…”

“…It has the features of continuous pumping, an ion source based on a RF driven helicon plasma [13] and a titanium drive-in target. The deuteron beam is accelerated by a double-stage electric field created between the ion source and the target by applying a positive and negative bias voltage to the ion source and target, respectively.…”

“…A new helicon plasma ion source was developed to supply a large current deuteron beam [13]. A detailed drawing of the ion source is shown in Fig.…”

“…The plasma discharge tube was made of quartz and the insulation components were made of Teflon Ò . In a previous study, the ion source was tested using hydrogen gas, which achieved a large current proton beam of 50 mA at 34 kV and an additional beam with a high monatomic fraction of 94% [13]. Fig.…”