x-ray solarization of borosilicate glass

Discussion in 'Physics' started by Jazz2C, Jul 8, 2016.

  1. Jazz2C

    Thread Starter Member

    May 27, 2016
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    Sry for asking a photochemistry question here but I couldn't find an AAC chemistry forum:confused:

    Anywho since HP the x-ray guru is gone fishing;) I hope someone here can help me?
    After total exposure of around 100,000 Gy (extrapolated from electrostatic dosimeter readings) to 120 kev energy, initially clear pyrex is almost totally opaque to optical wavelengths b/c of solarization. I know it's a well known phenomenon but I can't find a resource that explains the actual chemical changes? If anyone here has technical details or knows where I can find them I'll be grateful for your sharing!:cool:
     
    Last edited: Jul 8, 2016
  2. #12

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    Last edited: Jul 8, 2016
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  3. nsaspook

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    Aug 27, 2009
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    It's an effect we see in high energy system glass view-ports.

    https://www.orau.org/ptp/collection/xraytubescoolidge/coolidgeinformation.htm
    https://e-reports-ext.llnl.gov/pdf/243450.pdf
     
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  4. Aleph(0)

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    Mar 14, 2015
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    JC, HP was all through this on her thread which you said you totally read through:rolleyes: It's all to do with farbe centers cuz of ions in the xtal lattice. For interesting experiment you can heat the glass to make it clear again:cool:

    PS JC I know glass isn't crystalline in normal sense but it contains suspended crystals so don't go all nitpicky on me:p!
     
    Last edited: Jul 9, 2016
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  5. Aleph(0)

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  6. Jazz2C

    Thread Starter Member

    May 27, 2016
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    Yo Aleph! I searched the whole site. Hp only mentions solarization twice in passing on two different threads but not on EHT design thread:confused: So it must have been among the, as she termed it, "extraneous" material she deleted from the tutorial post?
    Thankie thankie!:)
    To what temp? I could save $600 a go if I can do it without deforming the plate!:cool:
     
  7. jpanhalt

    AAC Fanatic!

    Jan 18, 2008
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    Not my area of photochemistry, but from what I understand of farbe centers, annealing temperature (1050°F) should work, maybe lower. I would start at, say 600°F and see if that makes any change. When annealing glass, as when glassblowing, you can often get sufficient stress relief well below dull red.

    When you say you do not want distortion, how much is acceptable? Is this an optically flat window? If so, you might need a flat to repolish it after annealing.

    John
     
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  8. Aleph(0)

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    Mar 14, 2015
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    jpanhalt thanks:)! Is nice to know cuz I thought it would have to be heated to incandescence (like 1500F) for sure:oops:!

    I know the machine he's talking about, it's just a pane with frosted marks to cast calibrated shadows from visable light from collimator. I don't know if it's tempered or not but now that I think about it heating tempered glass could be interesting but I hope not as exciting as demolition of prestressed concrete:eek:!

    @Jazz2C Try breaking one of the junked out plates! If it breaks like window that's good but if it breaks into little cubes lake autoglass except windshield then it's tempered so be careful heating it and know that even if you can do it without shattering, it will lose its temper so try not to lose yours:p!

    JC you are worse cheapskate than me:rolleyes:! If you can get direct replacement for $600 why muck around with reusing solarized plate?
    If you are insisting on being cheap you can just etch thick window glass with HF solution to get graduations but be careful with enchant! If low PH doesn't get you, hypocalcaemia will:eek:!
     
    Last edited: Jul 13, 2016
  9. Jazz2C

    Thread Starter Member

    May 27, 2016
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    TNX to everyone for the replies!:)

    Actually minor refractive inclusions wouldn't matter, like Aleph says it's really nothing more than a transparency for optical light (wavelength centered around 550 nm):)

    Glad to know its disruption pattern is very similar to that of a residential window pane:cool:

    I know, you're right:oops: But student that I am even $600 is worth saving:oops:

    IMNSHO HF is a bad agent to be totally avoided outside the lab!
     
  10. Aleph(0)

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    Mar 14, 2015
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    Yup!
     
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