INSITU CALIBRATION OF A STREAK CAMERA IN NANOSECOND REGION WITH A SEQUENCED MULTISPARK SWITCH

This article presents an in situ calibration of a streak camera from 500 ps/mm to 20 ns/mm of streak speeds with an adjustable time-sequenced multispark switch. This switch is comprised of a trigatron which drives two other secondary sparks separated in time from several nanoseconds to almost 1 mus by simply varying their respective breakdown gaps. The spark light sources of less-than-or-equal-to 7-ns rise time from these two secondary breakdowns are coupled into the streak camera using optical fibers and the null streak span separating two parallel streak images corresponding to the time delay between their measured spark currents, thus allowing a streak speed to be calibrated. The main advantage of this calibration technique, besides simplicity and cost effectiveness of the multispark switch, is that the streak camera is easily synchronized without using any electronic delay unit.