CHARACTERIZATION OF 2-GATED MICROCHANNEL PLATE FRAMING CAMERAS

The overall performance of both a single- and a double-microchannel plate framing camera were measured. In the case of the double-plated device, only the front plate was gated. A short-pulse, 20-ps full width half-maximum (FWHM), uv laser was used to create photoelectrons on a time scale rapid compared to the temporal variation of the high-voltage gate pulse (965 V peak amplitude and 270 ps FWHM). Measurements were made of the variation in the light output pulse amplitude (8%-24%), width (85-115 ps), and peak location (+/- 22 ps), the latter corresponding to a temporal jitter. It was found that when a dc bias was applied to the plate (in addition to the high-voltage pulse) the output signal increased as the dc bias to the 13 and 5.2 powers, below and above a bias of 450 V, respectively, and a factor of 20 difference in signal between the single- and double-plate cameras. It was also determined that the rejection ratio drops from 500 to 1300 at a bias value of 450 V to 125-190 at 650 V.