INVESTIGATIONS ABOUT TRIGGERING OF COAXIAL MULTICHANNEL PSEUDOSPARK SWITCHES

A fundamental problem of pseudospark switches is erosion in the boreho le area. One way to reduce erosion is to distribute the current to sev eral discharge channels. Essential for multichannel operation is a rel iable ignition of all these channels. The aim of this work was to find out the requirements for a trigger for multichannel pseudospark switc hes and to develop a suitable trigger device. The investigations were made with a three channel pseudospark switch. The developed trigger is a pulsed hollow cathode discharge with a 3 mA dc-preionization. A tri gger voltage of 4 kV results in a current of about 6 A in the hollow c athode of the trigger-section. This hollow cathode discharge causes a trigger current into the hollow cathodes of the pseudospark chambers. The trigger current which is necessary to ignite an equally distribute d discharge has to be at least 3 mA into each main switch hollow catho de. A jitter of 2 ns was achieved for the coaxial multichannel pseudos park switch.