The main features of a conventional streak camera.
The scheme for a PE energy swept x-ray streak camera. Photons arriving at the transmission photocathode at later times experience higher accelerating voltage, have a larger Larmor radius, and are focused at a lower point on the phosphor. Not shown is the well known property of a uniform magnetic field that it refocuses a small divergence in PEs around the Larmor orbit.
The transition from a dc breakdown limit due to vacuum to a field emission limit with the transition given by the proton transit time across a gap (0.5 mm in this case).
The time dependent voltage in kilovolts applied to a gap of 0.5mm, and the PE exit energy in keV as a function of the birth time. As the voltage is rising the exit energy of the electrons is higher than the gap voltage when they are “born.”
The exit energy of PEs as a function of birth energy for a PE born at 60 ps, a 0.5 mm gap, and a 7 kV voltage ramping up in 100 ps. The higher birth energy electrons have a lower exit energy because they exit earlier in the ramp.
The assembly drawing of the precision photocathode-extraction structure. For testing by UV laser light the photocathode is coated inside of a quartz window. The voltage ramp is introduced by the two feed cables. The electrical connection is by spring finger contacts.
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