A halo tester is designed to analyze the halo formation in low-light-level (LLL) image intensifiers and the influencing factors on halo size. The tester is used to collect a 0.1922-mm hole image directly using a CoolSNAP<sub>K4</sub> charge-coupled device (CCD) in a darkroom under illumination conditions between 10<sup>-2</sup> and 10<sup>-4</sup> lx. The practical measurement result shows that the amplification ratio is 343.4. Then, the super second- and third-generation image intensifiers are placed after the hole, and the halo sizes of the hole images on the screens are determined as 0.2388 and 0.5533 mm, respectively.
© 2012 Chinese Optics LettersPDF Article