RE: Reality check

["Boyce, Dale" <DBoyce@intiso.com>]

Well if the airplane was at 30,000 feet it is above what about half of the
atmosphere?  So about 76/2*13 g/cm^2 ~ 500 g/cm^2 of predominantly N2.
Energy loss due to ionization would be about a GeV, but energy loss due to
nuclear reactions would dominate.  The p-p cross section is about 40 mb in
the GeV regime.  Cross section scale as about A^.333 so p-N cross section
should be around 100 mb.

500 g/cm^2 /14 g/mol *6E23 * 1E-25 = 2.14

exp(-2.14) = .12 

So it would be feasible for about 10% of a proton beam emitted directly
below the plane to reach it _IF_ it were a very high energy beam such that
the coulomb scattering didn't blow up the beam.  Without digging out a text
book to get a coulomb scattering equation a 1 GeV energy loss should cause a
1 TeV beam to diverge at least 1 part in a thousand so the beam would be at
least 30 feet in diameter.  So a 1 microamp beam (huge at this energy) would
contain a megawatt of energy.  But accounting for beam loss 90% and
divergence one would end up with about a 0.1 watt/cm^2 flux at the plane
(and probably only a small fraction of that would interact with the plane).


Hmmm.....

The plane was not flying over Fermilab or CERN

It would be hard to fit either FNAL or CERN on a ship

So one would probably have to have an airborne accelerator of somewhat lower
energy.  The weight, power, and distance tradeoffs there are many, but the
question then becomes why would anyone develop a particle beam weapon that
wasn't even useful at 6 miles?

> -----Original Message-----
> From:	Neil, David M [SMTP:neildm@id.doe.gov]
> Sent:	Wednesday, November 17, 1999 10:11 AM
> To:	Multiple recipients of list
> Subject:	Reality check
> 
> I was listening to one of the 'fringe' talk radio shows last night, where
> an
> opinion was advanced that the Egypt Air plane was downed by a release from
> a
> particle beam weapon.  My opinion as stated to my wife (after a prolonged
> razzberry :-P ) was that a particle beam in 1 atm air had, shall we say, a
> limited range due to attenuation.
> 
> But I thought I should double-check my opinion with the group, since I
> didn't have numbers to back it up.
> 
> Before drawing any conclusions from my media choices, bear in mind that I
> did refer to it as 'fringe' - sometimes thought-provoking, often amusing,
> and usually interesting.
> 
> Dave Neil
> neildm@id.doe.gov
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