Time-resolved pinhole camera for observation of nanosecond-duration x–uv plasma emission

A vacuum diode with a rear-mounted Pilot-B scintillator has been coupled with a conventional evacuated pinhole camera. The cathode of the diode is fabricated from 2-μ thick polycarbonate (Kimfol) with a 200-Å aluminum layer on the rear surface. Incident photons with energies above the carbon K edge (284 eV) are highly absorbed in the polycarbonate, but photons with energies below the K edge are absorbed in the aluminum and produce photoelectrons. This yields a photoelectron sensitivity which is peaked at approximately 275 eV. The photoelectrons are accelerated by a 10-kV cathode potential to an aluminum anode coating on the scintillator, and scintillation photons are observed with an image converter camera. Streak photographs of exploded-wire x–uv radiation taken with this system are presented.