The invention relates to a method and to a control unit for operating the plasma generation apparatus. The invention is based on a method and a control unit in which a voltage is applied as an ignition voltage between an anode and a cathode for ignition of a plasma. In order to enable a gentle operation of the plasma generation apparatus it is provided in accordance with the invention that a check is continuously carried out during the ignition process whether the ignition of the plasma has been effected. Additionally, the ignition voltage (U.sub.Z) is increased starting from an initial ignition voltage (U.sub.ZA) and after recognizing an effected ignition (at the point in time t.sub.Z) of the plasma, the voltage is reduced between the anode and the cathode to a maintenance voltage (U.sub.A).

An atomic flux measurement device for measuring the amount of dissociated atomic flux produced by discharge and emitted from a plasma generation cell into a vacuum camber. The atomic flux measurement device includes a counter electrode body including a pair of first and second sheet-like electrodes that are arranged substantially parallel to each other with a predetermined spacing between them, a direct-current power supply configured to maintain the first sheet-like electrode at a negative potential so that atoms attached to the inner surface of the sheet-like electrode undergo self-ionization and to apply a direct-current voltage between the first and second sheet-like electrodes so that a current flows between the first and second sheet-like electrodes, and a direct-current ammeter configured to measure a current flowing due to electrons emitted by the self-ionization of the dissociated atoms attached to the inner surface of the first sheet-like electrode.

Embodiments described herein relate to an apparatus that includes an inner rod assembly. In an embodiment, the inner rod assembly includes a first rod and a second rod oriented approximately ninety degrees with respect to the first rod. In an embodiment, a bridge is electrically coupled to the first rod and the second rod. In an embodiment, a first insulator is over an outer surface of the inner rod assembly, and a shell is provided around the inner rod assembly. In an embodiment, a second insulator is provided over an outer surface of the shell, and a housing surrounds the shell. In an embodiment, an interior surface of the housing is spaced away from the second insulator by an air gap.

A method for recognizing a process state of a plasma arc method, in which a workpiece is processed by a plasma torch and measured values of a time curve of a physical variable of the plasma arc method are detected and a signal curve is determined from the measured values. A pattern recognition is performed on the signal curve by extracting at least one feature from the signal curve and classifying the feature, and the signal curve is assigned to a specific state of the plasma arc method according to the classification of the feature.