Plasma characteristics of vacuum arc ion source by using time-of-flight mass spectrometry

Vacuum arc ion sources can be used to ionize both gases and solid substance. When the electrodes of the vacuum arc source are made of a metallic hydride, the hydrogen can be desorbed and ionized when vacuum arc is discharged. In this paper, the mass and velocity of ions in a pulsed vacuum arc plasma source were measured by time-of-flight mass spectrometry with orthogonal acceleration. The ion source consisted of a titanium-hydride as the cathode and operated by 40A~80A pulses. The element of plasma is hydride ion and titanium ion. The titanium ion had charge states of 1+, 2+, and 3+, with 2+ predominating. The hydride ion's amount was found 5% less than the titanium ion.