RE: cherenkov radiation

["Minnema, Douglas" <Douglas.Minnema@ns.doe.gov>]

Brian and others,

I agree about the cameras, we had the same problem at our fast burst reactor
at Sandia.  However, there are easier ways to check.  A large Co-60 source
will glow nicely in water from the same phenomenon, but I don't believe that
there is anything observed in air.  

On the other hand, I have personally seen a blue glow from high energy, high
intensity pulsed electron beams in air (10 MeV and 10 kA are the numbers I
recall) when we fired an electron accelerator outdoors after dark.  (No, the
beam was not directed into our eyes, and yes, we were a safe distance away
:-) We also captured it on polaroid film.  It was sort of like a faint
lightning bolt, and clearly followed the path of the beam.  

Interesting, thought.  As long as I have been hearing these discussions, I
had never put the two experiences together.  Perhaps there is something to
the claims after all.

As you stated, when you throw out E16 - E17 neutrons (and all the associated
photons and electrons) much of what you expect does not apply.

Doug Minnema, PhD, CHP
Defense Programs

what few thoughts i have are  truly my own ...

> -----Original Message-----
> From:	Brian Rees [SMTP:brees@lanl.gov]
> Sent:	Thursday, November 09, 2000 1:32 PM
> To:	Multiple recipients of list
> Subject:	Re: cherenkov radiation
> 
> I can tell you from personal experience that a video camera will not show
> a 
> blue flash, the instantaneous dose rate during the excursion overwhelms
> the 
> camera.  The picture doesn't recover for a good 10-15 seconds.  Yes, it's
> a 
> rad-hard camera.  Yes it's a ways away.  When you throw out E16 -E17 
> neutrons in a few microseconds much of what you expect doesn't apply.
> 
> 

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