PRODUCTION ENGINEERING MEASURE FOR LOW FIELD MAGNETRON BL-234C.
Quarterly progress rept. no. 3, 28 Oct 65-28 Jan 66,
BOMAC DIV VARIAN ASSOCIATES BEVERLY MASS
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The second group of engineering tubes, Tube Nos. 6 S through 10S, have shown significant improvement in performance over the first group of tubes. In general, 400 watts peak output power was exceeded in all tubes with considerably broader operating voltage mode widths. Operating life improved by a factor of more than 2 to 1 with tube 6S reaching 74 hours before pulse instabilities exceeded specified limits. An extended vacuum, bakeout, and activation procedure has been initiated during this period that will make, in all probability, 100 hours operating life readily achievable. Two cathode types have been processed in tubes using this procedure, the Bomac nickel matrix and the Spectra-mat directly heated tungsten dispenser, and initial life test results show promise. Receipt of the tungsten carbide modified broaches has been realized, and completion of the evaluation of conventionally machined modes is now expected near the beginning of the next quarter. Some difficulties have been encountered in obtaining pi mode resonance within the specified frequency range from anodes obtained from the next hob. The previous hob, from which four of the five tubes of the second group of engineering tubes were obtained, failed after a total of 68 pushes. Completion of rework of the Government furnished vacuum system has been delayed due to problems associated with flange and valve leaks in the ultra high vacuum portion of the system. Bell jar vacuum has exceeded 4 x 10 to the minus 6 mm Hg, which is more than adequate for tube envelope vacuum during extended temperature bakeout. Author
- Electrical and Electronic Equipment
- Fabrication Metallurgy