Time-integrated and time-resolved studies of pulsed ion beams from fast micro-capillary discharges

The paper reports on a micro-capillary discharge used as a point-like ion source. Since a very fast current rise (about 1013 A/s) is needed to ensure a very fast ionisation on the axis of symmetry a special fast driver was applied. It made possible to avoid the ablation of a capillary wall material and to facilitate an effective acceleration of the produced ions. With a current rise amounting to 1013 A/s, it was shown that an ion source of about 100 microns in diameter, and about 100 microns in length, could be formed in a reproducible way. Using different diagnostic techniques (time-resolved and time-integrated ones), it was shown t hat such a source can emit single charged ions with kinetic energy up to about 15 keV, depending on a material of capillary walls and polarity of the applied voltage pulse.