QUARTZ CRYSTAL AGING EFFECTS.

Aging mesurements of quartz resonators of low frequency, 100 Kc, 250 Kc, 455 Kc, and 500 Kc, 3 Mc, and 16 Mc and of various types of quartz were made. Of 96 low frequency resonators 85 were operable and 47 passed the acceptance aging requirement of 5 ppm for the first 30 days 44 passed the subsequent requirement of 2 ppmmonth. The predomi nant number of acceptance failures were in the 100 Kc and 250 Kc groups. Of forty 10 Mc resonators, 27 passed the aging acceptant test of 1 pp 10 to the 7th powerweek for 30 days and the subsequent aging requirement of 1 pp 10 to the 7th powerweek for the total aging period thus far of 230 days, resulting in a reliability figure of 100 per cent. The balance failed the acceptance test. The 16 Mc resonators 45 were exposed to gamma doses of 10,000 rads and displayed small average frequency shifts in accordance with the variety of quartz. Twenty-four AT-Cut quartz 3 Mc resonators were measured at 85C for 180 days. Although the aging rates varied markedly at first, after 105 days they were essentially the same except for cultured quartz. X-ray diffraction SID patterns have been made of twenty units with several different reflections. These patterns continue to show a fairly high incidence of distortion, localized twinning, and surface and interior defects among completed resonators. Author