RE: X rays, high altitude, and floppy disks

["Burns, Thomas" <BURNST@coned.com>]

Hi Paul,

Interesting question you have.I believe the x-rays do not affect floppy
disks. However maybe it is the the possible use of bomb detectors that are
magnetic in nature which may cause the problem. It takes a charge to effect
the disks. Maybe you should asked the vender if they scan the disks with a
magnetic device. The foil may be shielding the disks from the magnetic flux
of the detector.

Thomas Burns HPS
burnst@coned.com
Indian Point 2 Nuclear Power Plant

> -----Original Message-----
> From:	Dick King [SMTP:king@reasoning.com]
> Sent:	Tuesday, December 21, 1999 5:41 PM
> To:	Multiple recipients of list
> Subject:	Re: X rays, high altitude, and floppy disks
> 
> 
>  >Date: Tue, 21 Dec 1999 14:45:06 -0500
>  >From: "Paul R. Steinmeyer" <prstein@gyral.com>
>  >To: radsafe@romulus.ehs.uiuc.edu
>  >Subject: X rays, high altitude, and floppy disks
>  >Message-ID: <385FD8C2.CEF59A09@gyral.com>
>  >
>  >Hello All;
>  >
>  >I recently got a question from a software distributor regarding
>  >radiation effects on the software they distribute overseas (out of the
>  >US).  Their observation is that approximately 1 in 5 floppy diskettes
>  >are damaged while being shipped overseas; this problem does not occur in
>  >domestic shipments.  They assumed that the damage is caused by x rays
>  >used by customs inspection.  The damage is usually on the diskettes
>  >closest to the exterior of the package, and they say that wrapping their
>  >disks in aluminum foil eliminates the problem.
>  >
>  >Based on threads regarding radiation at high altitudes, my guess is that
>  >the long flight at high altitude might be a more likely culprit.
>  >
>  >Can anyone confirm of correct me?
>  >
>  >Thanks in advance,
>  >
>  >Paul R. Steinmeyer
>  >Radiation Safety Associates, Inc.
>  >RSA Laboratories, Inc.
>  >mailto:prstein@radpro.com
> 
> I have an alternate hypothesis.
> 
> Since the disks are inside the aircraft, which has an aluminum skin much
> thicker than any aluminum foil you're likely to be using to wrap the
> disks, i
> doubt that in-flight radiation is an issue.  Aluminum does not stop
> customs
> X-rays, so that's unlikely to be an issue either.  I've seen my fencing
> equipment go through customs X-rays.  The sword blades are steel, and they
> show
> up as completely opaque.  However, the guards are aluminum, about 2mm
> thick.
> They completely disappear in the X-ray image, which means that the X-rays
> go
> through the guards as if they weren't there.
> 
> I hypothesize that the problem is the long cold soak at altitude, followed
> by
> condensation.  To test this hypothesis, send a few disks through in sealed
> plastic bags, or in self-adhering plastic wrap.  My hypothesis would be
> falsified if the plastic-wrapped disks fail at a rate similar to the
> unwrapped
> disks.  Do make sure the containers are sealed.
> 
> -dk
> 
> ************************************************************************
> The RADSAFE Frequently Asked Questions list, archives and subscription
> information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html
> 
************************************************************************
The RADSAFE Frequently Asked Questions list, archives and subscription
information can be accessed at http://www.ehs.uiuc.edu/~rad/radsafe.html