# Electron beam/atmosphere interaction

1. Jul 14, 2008

### msquared

Hello,

This is something that's puzzled me for a while, but I haven't been able to find any conclusive answers anywhere. What I'm wondering is, how far would an electron beam (such as that found in a TV) travel in the atmosphere before it lost its kinetic energy or bonded with the air molecules?

I've heard about particle beam weapons being researched for anti-missile applications and such, so that makes me think it could potentially go quite a ways...any answers or even suggestions as to where I could look would be greatly appreciated!

2. Jul 14, 2008

### ZapperZ

Staff Emeritus
The electron mean free path in air is of the order of $10^{-6}$ m for an energy of the order of 10's of eV. It doesn't make a very good weapon, I would think.

Zz.

3. Jul 17, 2008

### msquared

Thanks for the quick reply, that's exactly what I was looking for!

Makes me wonder why they're researching them for military applications (for example, Medusa) though.

4. Jul 17, 2008

### Staff: Mentor

MEDUSA uses a beam of microwave pulses, not electrons. To make any kind of a serious electron beam weapon, you'd have to accelerate the electrons to very high energy.

As Zz stated, low energy electrons (10's of eV) won't get very far in the atmosphere. I used to do electron scattering experiments at those energies--those experiments had to be done in a high vacuum chamber.

5. Jul 17, 2008

### msquared

Ah ok, thanks for clearing that up for me.

6. Jul 17, 2008

### LURCH

I think that most of the research into electron beams as anti-missile weapons were assuming the interception of ICBM's outside the atmosphere by an orbiting weapons platform. Electron beams make fairly decent weapons in a vacuum, especially against a target with sensitive electronics on board.

7. Dec 27, 2011

### averagejoe11

Can this technology be used to complete an electrical circiut between conductors at any distance? Develop to detonate IED?

8. Dec 27, 2011

### Staff: Mentor

It would not complete a circuit unless it melts something and causes a short. Whether this is possible using microwaves I am unsure. (which is what I'm assuming your referring to, as an electron beam would be stopped by a few mm's of ground) If the electronics are shielded, which isn't hard, then I don't think so.
Although if it could be used as an IED detonator or minesweeper it would be pretty cool.