Ion Cannon physics

[alxian]

As per Ryan's post about a lightning propulsion system.. (funny because my name is Ryan too :P )

I have a question, general, about the concept of an Ion Cannon. While reading the Ashes of Worlds (not lightning weapon as described, they many 'directed energy beam'), the techno garble finally got to me. Lightning from space is a bit beyond silly. At least with my limited understanding of the associated physics.


Any large arc of lightning needs a source end and a target end and a channel to pass through. Lightning doesn't occur without a tracer coming up from the ground. Once there's a sufficient build up of potential energy on both sides, a conduit is spontaneously generated to allow a discharge.

If you consider the monumental amounts of energy required to generate that potential energy.. it seems difficult to expect any tiny human bread crumb space station to match the potential energy of a storm cloud. For starters. Then for there to be a big enough build up of potential energy from a ground side target to generate a conduit for a discharge.

Nevermind precision targeting. You're more likely to discharge the clouds.. which wouldn't be a half bad global power source if it can be harnessed. No more lightning for earthlings.



So I understand how HSV's technology ionizes the air first with a laser beam, which creates a conduit in the atmosphere for eletricity to pass from the source to the target.

What I'm still not sure about is how much that lowers the threshhold of power required to instigate a discharge.


How would you ionize 'space' so as to create this same conduit? Laser Beams can't ionize vacuum or conduct power on their own.

For the purposes of an orbital super weapon, wouldn't you need it to either have a conductive tether to the atmosphere which still requires a targeting laser to create the ionizing conduit through the atmosphere? Thus cheating and greatly enhancing precision targeting.


So,

1, a tracer round is first fired down from the orbital super weapon which creates a tiny conduit of ionized gas down to the atmosphere
2, a targeting laser bridges the rest of the gap which could even be fired up from the surface to orbit
3, where the tracer round and laser converge you've got your conduit
4, discharge

While the ionization of vacuum lasts you can keep discharging. Nothing stops you from continously dropping tracers to keep up the ionization.

Still the question remains of what kind of orbital installation would store enough juice for an orbital discharge. And why you'd risk back discharging a storm cloud and blow up both the ground target and the orbital super weapon.

[Jkirk3279]

You don't have to ionize space, just fire charged particles.

Fire hydrogen ions through a particle accelerator: whip the ions up to a really high speed.

The ions will zip out toward your target. Whatever they hit will get zapped.

There are a few problems.

One: throwing ions forward would propel your spaceship backwards. Not a big problem.

Two: Your spaceship giving off negatively charged ions would gradually become more and more positively charged. Eventually the negative ion beam you're emitting would be attracted back to you.

So you'd need to fire a positively charged beam in the opposite direction, thus maintaining your position and your neutral charge.

What would be even more cool would be if you could fire both beams at the same target: hit an opponent's ship on one side with the negative beam and the other side with the positive beam and watch the ship's plating melt !

As for hitting a ground target, the atmosphere would tend to scatter the particle beam. Although at least you'd create a massive lightning storm.