Uncle Al wrote:
Dirk Bruere at NeoPax wrote:

I once did a calculation for a NG, sci.military.moderated IIRC,
concerning the lethality of the hypothetical weapon given a beam pulse
energy comparable to the muzzle energy of a conventional handgun (about
700J).

The question I could not answer concerned its effect on the user of the
weapon. Would there be enough back scatter from the air at the muzzle
and along the beam path to seriously endanger the health of the firer?

How short is the pulse?

An M16A2 rifle has a muzzle velocity of 2800 ft/sec. The bullet
travels one foot in 0.3571 msec. 700 J in 0.3571 msec is 1.96 MW. The
air would massively ionize. Worry about thermal and UV burns, then
soft x-ray backscatter.

I don't understand this estimate. It assumes the 700J energy of the
bullet is entirely expended in the first foot of air after leaving the
muzzle, after which the bullet would presumably drop to the ground. In
that unrealistic case maybe the 2 MW pulse would "massively ionize" that
foot of air. The beam of a GRG would also, presumably, not lose all its
energy in one foot of air. How does your estimate relate to the original
question?

- Dushan Mitrovich