On Abnormal Acceleration of Ions at Initial Stage of a Pulse Vacuum Arc

Abstract – Results of experimental investigation of the pulse vacuum arc of the MEVVA type with different materials of the cathode are presented. It is shown that the Langmuir probe signals for both ion and electron components plasma jet for Al and Mg cathodes have a pronounce peak in the begin-ning of the pulse. The signals for Ti and Zr cath-odes have the more rectangular form. In addition, it is shown that signals from the ion energy ana-lyzer also have the similar peak at high energies. It is shown that the ion energy spectra are changed significantly through the discharge pulse. Namely, the spectrum of ions produced at the peak of dis-charge current has the most likely energy and a tail of high-energy particles as compared to ions pro-duced at plateau of the discharge current. High-energy ions from tail of the spectrum are produced in front of the discharge current, these in vicinity of maximum of the spectrum are produced in maximum of the discharge current and the slow ions are produced at plateau of the current pulse. 1