Laser Weapons

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06 Aug 2012, 6:48 pm

I used to imagine that sometime in the future, lasers would replace guns as small arms. Keep in mind that ITT I am actually not talking about Directed Energy Weapons designed to shoot down missiles. What I am talking about is a shoulder fired laser that produce a pulse lasting several seconds with an energy range in the hundreds of kilowatts to several megawatts. It would almost be like a flamethrower but far more powerful. Any thoughts on this idea? I am determined to build it but not sure what lasing mechanism to user: Chemical or electrical.

ruveyn
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06 Aug 2012, 6:51 pm

AspieRogue wrote:

An energy generator capable of powering a laser that could cut through metal or flesh would be rather bulky. The closest thing we have to -storing- that kind of energy is tanks of hydrocarbons to burn or explosives to propel hard bullets. The ideal weapon would be the firearms we all know and love.

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06 Aug 2012, 6:52 pm

The size of the energy supply is a huge problem. That's the reason such systems are mounted on ships.

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ruveyn
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06 Aug 2012, 6:55 pm

John_Browning wrote:

The size of the energy supply is a huge problem. That's the reason such systems are mounted on ships.

For energy storeage it all comes down to joules per kilogram mass. The champions in that department are chemical explosives and hydrocarbons to burn. I am excluding nuclear weapons from consideration because of production and storage costs.

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naturalplastic
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06 Aug 2012, 7:52 pm

In laymen's terms: you want bring Star Wars/Star Trek and a centurey of comic books to life by enabling police and soldiers to fire laser beam guns instead of bullets.

Not only would each infantrymen (or cop) have to walk around with a powerplant-in-a-backpack the wieght of a house to generate the energy needed, but in the several seconds it would take for the beam to start burning the target's skin the enemy could whip out a compact mirror and reflect the "ordinance" back at the shooter! Or the perps might start wearing aluminum foil as "bullet proof vests".

Lol!

Am old enough to remember when Masers, and Lasers, were first invented, and seeing Isaac Asimov explain the concept on TV to me as a kid. And me thinking that now theyre gonna starting using "death rays" in warfare just like the aliens do on the cheesy late night movies. But what actually happed was that lasers DID start going to war in the next decades, but as the eyes to guide ordinance, and not AS the ordinance itsself. Now we have laser guided smart bombs. And we have sharp shooter rifles that put a red dot on the bad guy's forehead for you to aim at ( or atleast they have that in the movies). There are good reasons why the technology went that way instead of the way you want to take it.

AspieRogue

06 Aug 2012, 8:25 pm

John_Browning wrote:

The size of the energy supply is a huge problem. That's the reason such systems are mounted on ships.

That's true. However, you and ruveyn should bear in mind that chemicals bonds can store considerably more energy in smaller amount of space than batteries. Which is precisely why I favor chemical lasers for such a device.

edgewaters
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06 Aug 2012, 8:25 pm

Reflection is a major problem - not just mirrors. Precipitation, fog, dust, or possibly aerosols could render them very unreliable.

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06 Aug 2012, 10:30 pm

edgewaters wrote:

Reflection is a major problem - not just mirrors. Precipitation, fog, dust, or possibly aerosols could render them very unreliable.

That's certainly true. Along with the phenomenon of "blooming" when the energy carried by the beam is high enough to ionize air. But what you are talking about is not reflection, it's scattering.

enrico_dandolo
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06 Aug 2012, 11:54 pm

Even if the technical problems were solved, the cost would probably be very high for no significant tactical advantage, at least as small arms.

John_Browning
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07 Aug 2012, 12:22 am

AspieRogue wrote:

John_Browning wrote:

The size of the energy supply is a huge problem. That's the reason such systems are mounted on ships.

To get the size of energy supply you would need, especially to fire more than one shot per reload, you would have to find a way to convert mass to pure energy using a minute fraction as much energy compared to that released. If you pull that off, expect a plane ticket to Stockholm in the mail.

auntblabby
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07 Aug 2012, 1:55 am

the brief flash of a green or blue laser of about 1 watt [just powerful enough to be brightly visible in daylight], when the beam is decorrelated somewhat [you don't want to permanently blind somebody] and aimed right between the eyes, makes a good dazzling distraction that lasts long enough for one to run away.

Apple_in_my_Eye
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07 Aug 2012, 2:45 am

This thread got me browsing Wikipedia and I ran across this:

http://en.wikipedia.org/wiki/Directed-e ... ectrolaser

Quote:

Electrolaser
Main article: Electrolaser

An electrolaser lets blooming occur, and then sends a powerful electric current down the conducting ionized track of plasma so formed, somewhat like lightning. It functions as a giant high energy long-distance version of the Taser or stun gun.

I don't know the practical constraints, but a lightning-bolt-gun would be "way cool."
It might tick-off Zeus, though, with humankind stealing/replicating his power.

On a more serious note, that might be a more efficient way to deliver energy to a target than a laser by itself.

Apple_in_my_Eye
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07 Aug 2012, 2:50 am

And from the same page as the above:

Quote:

High power consumption

One major problem with laser weapons (and directed-energy weapons in general) is their high electric energy requirements. Existing methods of storing, conducting, transforming, and directing energy are inadequate to produce a convenient hand-held weapon. Existing lasers waste much energy as heat, requiring still-bulky cooling equipment to avoid overheating damage. Air cooling could yield an unacceptable delay between shots. These problems, which severely limit laser weapon practicality at present, might be offset by:

1. Cheap high-temperature superconductors to make the weapon more efficient.

2. More convenient high volume electricity storage/generation. Part of the energy could be used to cool the device.

Chemical lasers use energy from a suitable chemical reaction instead. Chemical oxygen iodine laser (hydrogen peroxide with iodine) and deuterium fluoride laser (atomic fluorine reacting with deuterium) are two laser types capable of megawatt-range continuous beam output. Managing chemical fuel presents other problems, so the problems of cooling and overall inefficiency remain.

This problem could also be lessened if the weapon were mounted either at a defensive position near a power plant, or on board a large, possibly nuclear powered, water-going ship. A ship would have the advantage of water for cooling.

ruveyn
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07 Aug 2012, 8:28 am

A laser can be defeated by dust, mist, fog and mirrors.

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John_Browning
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07 Aug 2012, 9:41 am

ruveyn wrote:

A laser can be defeated by dust, mist, fog and mirrors.

ruveyn

Or a lightsaber!