Spectroscopic investigation of high-current vacuum arcs

First experiments on high-current vacuum arcs at the arc research laboratory of INP Greifswald are presented in this work. The laboratory was recently built up and includes two synthetic test circuits providing currents in the 10 kA range at maximum voltages of 18 kV. The discharge apparatus consists of an ultra-high vacuum chamber. One of the electrodes is moved by a pneumatic device simulating the conditions of a vacuum circuit breaker. The arc behavior of the test electrodes immediately after the electrode separation without application of external magnetic field is observed by a high-speed video camera. Besides the usual electrical measurements the emission in the gap along the axis is investigated by optical emission spectroscopy.