RE: blue flash and criticality

["Franta, Jaroslav" <frantaj@aecl.ca>]

Incidentally, I think that there is lots of photographic evidence which
provides the "data" to which the "theory" must be fitted ( I am alluding
here to recent statements on this listserv, that theory must fit the data
and not vice versa - as has been done in the past by people like Sternglass,
Bertell, etc....).

Specifically, I'm thinking of photos of the 1960s & early 1970s US tests of
the Rover and Nerva nuclear rockets. 
Going full blast at something like 1000 megawatts thermal, with very little
external shielding (dose rates out there in the desert of Jackass Flats were
reportedly at a level that would be lethal in seconds at a distance of ~100m
), one could make out the faint glow of the super hot hydrogen rocket plume
exiting the nozzle, but there was definitely no blue glow from Cerenkov
radiation in the air surrounding the reactor (though there would presumably
have been lots of it INSIDE the pressure vessel, since its supplied with
liquid hydrogen...). 
No doubt there are other examples of photos of this sort - such as the
outdoor tests of bare critical Pu & HEU spheres, the HPRE, the various
aqueous reactor experiments (including the very first at Los Alamos), etc. -
which simply haven't been published much because there's nothing to see (ie.
one wouldn't be able to tell the difference anyway between whether the
reactor was operating or not....).

Regarding James Dukelow's reference to "Cherenkov "glow" ....in air...where
it is the basis for an "instrument", the STACEE (Solar Tower Atmospheric
Cherenkov Effect Experiment), that uses a heliostat array and a
photomultiplier to detect the atmospheric trace of particle "showers" caused
by extremely high-energy gamma rays arriving from active galactic nuclei,"
--  I presume that this instrument only works at night in very dark sky
conditions, in order that it avoid the problem of differentiating between
the cosmogenic Cherenkov "glow" and the blue background of the daytime sky.
But would it not also have problems with the blue light from stars ?  What
exactly is the wavelength of this cosmogenic Cherenkov "glow" ? ...could it
be in the gamma-ray part of the spectrum, detectable even in daylight ?

Another colleague mentioned that  it is also common for astronauts to see
blue Cherenkov "glow" flashes 
from high energy particles hitting their eyes as well - can anyone confirm
this ?

Thanks again.

Jaro 
frantaj@aecl.ca

-----Original Message-----
From: Michael C. Baker [mailto:mcbaker@lanl.gov]
Sent: Wednesday November 08, 2000 3:12 PM
To: Multiple recipients of list
Subject: Re: blue flash and criticality


The blue flash, that is typically described following a criticality 
accident, is due to light produced from interactions in the eye 
itself.  Therefore the container does not have to be transparent and the 
system does not have to be aqueous as you stated.

Mike ... mcbaker@lanl.gov
--
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