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Re: [APML] To freeze, or not (Was: The good Supra 400pricereduction...)

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>>>>> "Philip" == Philip Perkins <philip@astrocruise.com> writes:

    Philip> I am not so sure about fogging due to cosmic rays - we
    Philip> know that CCD detectors record them but do we know for
    Philip> certain that film records them?

Film will record them.  Under normal incidence in an old-style film
detector, they will leave point-like marks.  Sitting in your fridge in
the canister in a random orientation....they could leave just about
any kind of mark at all.

The muon flux at sea-level is remarkably high; it is about 1 muon per
square centimeter per second.  They are energetic enough to penetrate
right through the house and into that basement fridge, unless you
happen to live in a very deep hole (oh, say about 5-10 meters below
ground with rock fill over the hole).  The amount of energy they
deposit in the film is small, but over time I can see how it might
degrade the film.

regards,

roland
- -- 
		       PGP Key ID: 66 BC 3B CD
Roland B. Roberts, PhD                             RL Enterprises
roland@rlenter.com                            6818 Madeline Court
roland@astrofoto.org                           Brooklyn, NY 11220

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