Do they not run on deuterium pellets?
You could keep them dropping into the reactor at a fast rate, and though you'd still only be "burning" one at a time as they reach the laser focus, it would appear continuous to the naked eye.
All you really need is a reasonably steady output (capacitor), and adjustable power for when you need the extra juice to run and shoot.
Yeah:
The explosion would be basically a bunch of super-hot hydrogen, helium and disassociated mech parts flying around.
Tin foil on riot gear should protect you from the bLast and heat. You'll have to depend on luck to not be splattered by the hail of oversized nuts and bolts.
