Alternate laser weapons

[Rahnd]

Anyone given any thought into different spectrum lasers? any thoughts on a X ray laser weapon, or infra red laser? been a while since i have taken science, so might not work. I remember reading though something on a X ray laser, the beam being invisible.

food for thought, and comments or ideas?

 

[Rahnd]

And i also just realized i posed this to the wrong board...Any admin want to move it?

 

[Andrew]

All laser beams will be pretty much invisible , as it stands. A laser is a coherent beam of light and in a vaccum the sole effect will be the release of energy at the target sight.
If there is a lot of dust or other material such as smoke there may be some visual effect caused by light scattering from the beam however this also reduces the energy deleivered to the target.

In an atmospher high energy laser beams may ionise the air producing small spark trails or condensation.

If you want visible energy beams like Films have use Plasma weapons that will look like a beam.

UV/IR/X-Ray lasers are all possible they are fundementally no different to Visible light lasers however as the Wavelength of the light decreases (UV/X-Ray) it requires more energy so such weapons are higher tech . I beleive FFS 1 and probably FFS2 have guidelines on when each frequency becomes available,
All weapons will probably have some degree of tunability if intended for atmopsheric use as different atmopsherese are aborbant at different wavelengths of light.

I hope this was helpful

 

[vegascat]

Stiker book 3 pg 18 has rules for X-ray lasers.
They can be used at TL13 or better. The basic effect is higher penetration for the energy used.
Secondary effects are the beam is not visible in hazy air and penetrates aerosol screens better.

 

[tjoneslo]

Originally posted by Andrew:
All laser beams will be pretty much invisible , as it stands.

In an atmospher high energy laser beams may ionise the air producing small spark trails or condensation.

If you want visible energy beams like Films have use Plasma weapons that will look like a beam.

Any laser powerful enough to be used as a weapon will leave an impressive trail of sparks and plasma explosions, hardly invisible.

Air absorbs x-rays almost as well as steel, making an X-ray laser uselsess in the atmosphere. The x-rays from a weapons grade laser would cause the atmosphere at the end of the laser to explode. Not very healthy for the user. In space you want an x-ray (or higher frequency) laser because it gives you better range before diffusion renders it useless.

There is some thought of using a Free Electron Laser (FEL) as a weapon system, partly because you can tune the laser to better penetrate various atmospheric conditions.

The other idea is to use a multi-frequency laser, which fires several lasers of different frequencies at the same time. The idea is (again) to match atmospheric conditions to improve damage at the far end.

 

[Anthony]

Well, the tendency to produce sparks and atmospheric plasma is a major limiting factor on lasers; if the laser is powerful enough to cause plasma formation in atmosphere, the atmosphere becomes opaque and stops the laser outright, unless it's a _really_ powerful laser, in which case it can simply 'burn' through the atmosphere, creating an evacuated tube (figure atmosphere is good for around 1 cm steel per 200 meters range, or around 50 cm steel for orbit to ground)

From what I recall, a near-IR laser is limited to around 10 MW/cm^2, visible light lasers have lower limits. This limit will make it very difficult to have any sort of effective weapons-grade laser in atmosphere (for a 10 millisecond beam, that's a limit of 100 kilojoules/cm^2, and you need to keep the beam focused on one point for 10 ms, which is actually fairly tricky). However, the beam won't be terribly visible unless there's smoke or dust in the path, which there probably will be.

 

[Spyder_GS]

For your reading pleasure...

http://www.defensereview.com/352003/TIS1.pdf

The future is, perhaps, not so far away.

 

[Tom Schoene]

Originally posted by Spyder:
For your reading pleasure...

http://www.defensereview.com/352003/TIS1.pdf

The future is, perhaps, not so far away.

This is an insane concept, not at alla feasilble weapon. Here are my obsevations from a Usenet post:

1) Heat dissipation. You cannot throttle or shut down a radiothermal generator (RTG). They have posited a power pack that produces 100+ kilowatts all the time, in use or not. At very least, it's going to be a massive IR source, if not an actual burn hazard to the user.

2) Power pack life and storage. RTGs run constantly, which means that notional 60-day life starts the moment the power pack is fabricated. So you have to ship them from the factory to the front lines in less than a month.

3) Radiological hazards. Polonium is extremely hazardous. Hit one of these power sources with a rifle bullet and you've contaminated a signficant area with prossibly lethal doses of Po-210. (and it doesn't take much; since it's a very potent alpha emitter, any inhalation will be very unhealthy.)

4) Manufacturing. They gloss over the very severe difficulties involved in growing polonium manufacture from micrograms to tons per year. It exists in absurdly small concentrations in nature and building new reactors to breed it seems very unlikely (if it's even possible).

Someone else observed that the beam aperture and laser frequency given leads to beam radius of 15m at a range of 1500m, which means a power density just about enough to warm the target a few degrees. You don't get a lethal concentration until ~15m range or less.

 

[Spyder_GS]

Absolutely. But these are not insurmountable problems. I would bet on a working useable prototype in 5-10 years.
Lasers have already been tested for anti-missile uses. Likely we will see the first generation of man portable energy weapons in use in our lifetimes.

 

[Anthony]

Originally posted by Spyder:
Absolutely. But these are not insurmountable problems. I would bet on a working useable prototype in 5-10 years.
Lasers have already been tested for anti-missile uses. Likely we will see the first generation of man portable energy weapons in use in our lifetimes.

Actually, in terms of the specific design involved, several of the problems _are_ insurmountable. I wouldn't bet on seeing man-portable directed energy weapons in our lifespan, for the simple reason that, while it will probably be possible to build something that can kill a human, it will probably not be possible to build a something that can kill a human better than a rifle of similar size.

 

[Tom Schoene]

I'm sorry, but these that specific approach to portable laser weapon design is unworkable with any amount of development.

Direct energy input lasers are possible int eh next 10-15 years, but they will be vehicular weapons. It's vaguely possible that w'll se man-portable lethal lasers in the next 50 years, but it's going to be very hard to find any reason to use them rather than improved kinetic energy (bullet-firing) weapons. Even highly optimistic projections simpy don't create power sources with enough energy density to replace gunpowder.