Hi The only known impact of radiation on quartz crystals is to move impurities around in the lattice. That's going to be a bad thing. There have been many papers on this. If you want to dig into them, digging into a good index of the FCS proceedings is a good starting point. The crystals shown in the movie were going into pressure holders. The whole stress / strain / frequency thing was well in the future in 1943. Bob -----Original Message----- From: time-nuts-bounces@febo.com [mailto:time-nuts-bounces@febo.com] On Behalf Of Charles P. Steinmetz Sent: Thursday, August 01, 2013 9:53 AM To: Discussion of precise time and frequency measurement Subject: Re: [time-nuts] How quartz crystals are (were) fabricated Bob wrote: >The X-Ray process does nothing good to the crystal. It's impact is >highly dependent on how "dirty" the crystal is. Bob, Do you have authoritative references for this proposition? If not, can you identify what data and what inferences it is based on? I could imagine the X-ray process relieving stress in the crystal (perhaps to advantage), or disrupting the crystal structure (likely detrimental). I'm interested to know if anyone has researched this in a systematic way and, if so, what they found. (My intuition favors the disruption hypothesis over stress relief, but I'm much more interested in research and data than in intuition or speculation.) Data on other forms of radiation would also be interesting, if research has been done. (We already know that heat can be beneficial, at least in certain circumstances, so I'm not so interested in that at the moment.) Of course, when the X-ray technique was developed most crystals were not housed in evacuated holders, so atmospheric and environmental factors were larger contributors (at least to aging) than they are today. That could have obscured researchers' ability to discriminate the effects of the X-ray treatment in contemporaneous testing. Best regards, Charles _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.