During this quarter, the bell jar vacuum system demountable setup was completed and one assembly using a stock gun was made to check the electron optics of the ballistic and post acceleration region in which both regions had uniform pitch spiral banding. A second assembly was made using a stock gun and a graded pitch spiraled post accelerator. A third assembly was made using a gun specifically designed for this tube with regard to its electron optical performance and the ballistic and post accelerator of the second setup were used. In parallel with the above effort, two sealed off gun test tubes and three sealed off phosphor test tubes were made. The conclusions from the above studies were as follows: (1) a uniform field in the ballistic region was desirable;(2) a graded pitch spiral in the post acceleration region gave divergence which improved the deflection sensitivity at full scan;(3) some pattern distortion resulted from lack of field matching between the ballistic and post acceleration region;(4) the overall system with the gun designed for this tube should be capable of giving an unelected spot size of 0.0018 inches;and (5) P28 phosphor was not a good candidate for high resolution work.
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