抄録
We have analyzed the pulsed electric field of a high-speed framing camera with the proximity focused image intensifier (PFII) using the three-dimensional finite-difference time-domain (FD-TD) method. When the temporal resolution of sub-nanosecond is required for a high-speed camera, the non-uniform propagation of the gating pulse over the electrode degrades the quality of the image, as has been reported experimentally by one of the authors. The present calculation successfully simulated such a degradation when a circular electrode ahead of the photocathode was divided into two electrically independent semicircles. The reason for this degradation has been attributed so far to the unwanted propagation, or leakage, of field around a guard electrode that divides the circular electrode. We have found, however, that this is not the case, and that this is due to the leakage electric field propagates through the space between the photocathode and the electrodes. Certain methods to resolve this problem have been suggested.
