Laser Guns or Rail Gun

yeah ur right wouldnt want to near the cooling system if it got punctured

on what theatre are you going to use this railgun ?

where to plug in ?
what about the weight of magnets+installation to transport ?
what about people to service the device ?
what range are you going to use the device strategicaly speaking ?

Originally posted by NOGODSINTHEUNIVERSE
on what theatre are you going to use this railgun ?

it could be used for ground or sea or space theatres

where to plug in ?
any reactor powerful enough

what about the weight of magnets+installation to transport ?

it doesnt have magnets all it has is rails and cables well mabye some capactiros but i dont really know

what about people to service the device ?
engineers duh

what range are you going to use the device strategicaly speaking ?
what ever range is needed or until it runs out of momentum

Originally posted by NothingMakesSense
I have a question about lasers:
Since lasers are just concentrated light, could they be foiled by a mirror?
If so, the obvious defense is to coat all our armoured vehicles with a reflective substance.

Originally posted by Amur_Tiger
...if you use the same reflective material that the laser uses to get the ray concentrated then it would work. Also a good cooling system would make this a non-issue, Liquid Ox tanks on the outside could actually become a good thing.

Lasers and mirrors...

ATS member NothingMakesSense, while it is true that lasers are "just concentrated light" (amplified), mirrored surfaces may not be as advantageous as one may think.

ATS member Amur_Tiger rightly refers to specific materials used to reflect laser energy, however considering liquid oxygen as a coolant to keep a concentrated heat source such as a megawatt laser from destroying a target will make for some rather spectacular fireworks.

Here are a few points of clarification on laser reflectivity...
(I actually posted this information in another related thread but I did a slight rewrite to cover this subject matter)

1.) No surface is 100% reflective.
The energy that is not reflected is dissipated by the surface as heat. As heat builds up, the reflectivity of the surface will decrease, and it decreases exponentially from that first contact. This will impede the time it takes a laser to inflict damage on a target, but at the mega-power levels of battlefield lasers it would be measured in nano or milliseconds as opposed to seconds.

It is helpful to realize that even mirrors for lower powered industrial lasers need to be water cooled, in spite of being over 99.5% reflective for this reason.

2.) For a surface to remain highly reflective, it has to be kept incredibly clean. A $600 germanium mirror for a 500 watt CO2 laser can be easily destroyed in a fraction of a second if it has so much as the residue of a finger print that has been wiped off with a lens cloth without benefit of cleansing solvent.

For tanks/aircraft/missiles to be able to reflect enough of a weapons-class laser beam to be impervious, they'd need to be polished to an optical grade and wiped off to clean-room specs. Not the sort of thing that's practical in combat.

3.) Surfaces are only reflective to a certain range of wavelengths; in other words, what mirrors light in our visual wavelength does not necessarily mirror light in another wavelength.

As an example, the $600 germanium mirror I talked about above is reflective to CO2 lasers in the far infrared wavelengths (10.6 microns), it is glossy black and completely unreflective to visible light which as a reference centers around .4 microns.

On the other hand, a mirror for a Ruby laser, which outputs radiation at .69 microns is standard silver. If you switch the two mirrors with their respective lasers, each will shatter immediately.

If an enemy were to armor their vehicles/missiles with a reflective coating, provided they could keep it clean and polished in battlefield conditions (impossible unless in a particle free perfect vacuum), the resonant cavity optics of the laser could theoretically be changed to amplify a wavelength that the reflective surface would be vulnerable to.



[Edited on 18-5-2004 by intelgurl]

intergurl you definitely know your stuff. Do you mind me asking how you know so much about lasers?

Originally posted by NothingMakesSense
intergurl you definitely know your stuff. Do you mind me asking how you know so much about lasers?

I have been around lasers in my work experience.

Rail guns do have recoil, just because there is no explosion pushing back on the barell does not mean there is no reactive force. A car fan motor or any motor for that matter has rotational recoil when the rotor spins up. The rail gun power supplies can be small but the capacitors that store the power must be pulse discharge type and huge!.

As for lasers, a giant Nd:glass slab laser that is Q switched can blind every one on earth in one pulse if every one could see the "invisable" dot. Even small lasers can punch through steel. About 2-3 camera flash units has enough power to pop through a razor blade if the yag rod used is Q switch and focused. Least laser googles would become cheap then!

BTW intel, what line of work are you in and do you have any 1,064nm dye cells or 1/4wave plates that need a home?

A commonly overlooked problem with rail guns is the torquing of connections out of position. When the massive current passes from the capacitors through wires to the gun, the electricity creates a magnetic feild which will rip wires off other wires, twist them around in impossible positions, and knock stuff (like capacitor i'm guessing) over. So every part of the rail gun must be very strong and very well attached to something, as well as well grounded.

The recoil from a rail gun is not as strong as a comparable chemical weapon bu there is a recoil.

Originally posted by XL5
As for lasers, a giant Nd:glass slab laser that is Q switched ...
BTW intel, what line of work are you in and do you have any 1,064nm dye cells or 1/4wave plates that need a home?

Regarding powerful Nd:Glass slab lasers, etc...

The largest solid state laser ever is being constructed at the National Ignition Facility at Lawrence Livermore Nat'l Lab. The NIF laser which has 192 beam lines and is designed to produce around 1.8 MJ per pulse with a power output of over 500 Terawatts has already exceeded it's design parameters.
This laser is about the size of a football stadium and has approximately 3,000 Nd:Glass slab amplifiers nearly a meter across.

Glass slab lasers however are not practical for weaponization as the slab does not dissipate heat quickly enough (low thermal conductivity) and the susceptibility of glass to solarize.

Regarding the 1064nm dye cells... no, unfortunately I know of no components that need a home - are you involved in some kind of medical or cosmetic/surgical research?

Originally posted by NothingMakesSense
A commonly overlooked problem with rail guns is the torquing of connections out of position. When the massive current passes from the capacitors through wires to the gun, the electricity creates a magnetic feild which will rip wires off other wires, twist them around in impossible positions, and knock stuff (like capacitor i'm guessing) over. So every part of the rail gun must be very strong and very well attached to something, as well as well grounded.

The recoil from a rail gun is not as strong as a comparable chemical weapon bu there is a recoil.

There are Scientific /Industrial applications currently in use which have deal the electromechanical phenomena you describe. NMR/NMRS systems and their more common counterpart the MRI scanner (Found in your friendly neighborhood Radiology Department) use high speed gradient (current amplifiers) systems to bend static magnetic fields (this is what causes the "knock") there are ways of shaping your input pulse (ramping, spoiling, tuning so to speak) that will minimize this EM resultant. The LC impedance must be matched in order to prevent any oscillation (nutation of the projectile release point is just as detrimental to accuracy as laser emitter / mirror jitter) This problem is easily engineered away in comparison to the more intractable power supply / projectile issues.

There are Scientific /Industrial applications currently in use which have deal the electromechanical phenomena you describe. NMR/NMRS systems and their more common counterpart the MRI scanner (Found in your friendly neighborhood Radiology Department) use high speed gradient (current amplifiers) systems to bend static magnetic fields (this is what causes the "knock") there are ways of shaping your input pulse (ramping, spoiling, tuning so to speak) that will minimize this EM resultant. The LC impedance must be matched in order to prevent any oscillation (nutation of the projectile release point is just as detrimental to accuracy as laser emitter / mirror jitter) This problem is easily engineered away in comparison to the more intractable power supply / projectile issues.

So what you are saying is that controlling the pulse will negate the problem? And what is LC impedance? I'm not an electrical engineer.

............Right, the entire cleanliness factor yeah I should have thought of that........... too much time working in 3D max where everything is perfectly clean.

too much time working in 3D max where everything is perfectly clean.

Ah! That makes two of us!! Too bad there isn't a "grime" plugin where you specify the age and what type of environment the grime should come fomr...

Originally posted by NothingMakesSense
And what is LC impedance? I'm not an electrical engineer.

L=Inductance

C=Capacitance

These values will vary according to conductor length and diameter(L), space between conductors(C), the material between them (dielectric, part of C) versus the frequency of the input (or rise time of a single input pulse, we won't even consider a rapid fire rail gun right now) this is the impedance (resistance) to the input current. The best example of this in common household terms are loudspeakers for audio / video. The voice coil is an LC circuit, the current drive from the amplifier is your power source, the music modulating the current, your pulse. Most of the better OEM's include a plot of a speakers impedance versus input frequency, this will illustrate in the most basic of terms the obstacle of applying a high current pulse to a straight piece of wire.

I'll try to address the problems / benefits of doing this in a static magnetic field. I'm wrestling a 1.5T now.

I think if they put UV filters/coatings on the lamps or slabs then at least Nd:glass could be used as a very low pulse rate weapon.
I had a chance to buy a NIF/pharos III laser amp for 300$ but it was too big and I didn't have the money at the time, got a picture of it though.

Im just into lasers as a hobby. Im curently making a 300mJ (or so) 10Hz yag out of a suplus Lasag, some bastige took the optics and messed the alingment of the Q-switch.

The problem with railguns is the damage to the rails.

They have to withstand insane temperatures from the high currents and the projectile sliding along them at insane speeds.

Afaik they are have not solved these problems anywhere near to the degree that you could make a tank with a railgun as effective as tanks are today.

Oh yeah, they use insane amounts of power aswell. With the worlds energy situation as it is, I would say that current military equipment isn't going to be feasable in 20 years. Fat lot of good it is to have tens of thousands of fighters, bombers and tanks when they can't move

The first practical application of Rail Guns will probably be as a direct fire naval weapon. A ship of the line will have sufficient power, room for fire control, energy storage, and a constant cooling source (second stage chiller with seawater). Not to mention the problem of a Rail Guns flat trajectory (this also applies to lasers) a hilly or mountainous terrain or one with heavy undergrowth would leave a tank with few options for engaging a threat that has even moderate parabolic munitions delivery or a munition that relies on mass / contained energy. The double edge sword of light projectile / hyper velocity is less of an issue on what amounts to an obstruction free environment. A ship is also an excellent target, too large to attempt active armor (modern systems put an incredible strain on naval architecture, the days of a heavily armored battlewagon are gone) so even a relatively small (by naval artillery standards) projectile would be effective.

[Edited on 19-5-2004 by Mirthful Me]

So AGAIN,

Laser= makes a great sniper weapon

Rail Gun= great penetrator weapon

Neither do much damage though

Originally posted by robertfenix
A Chemical Laser is the way to go. Compact power source, low input power and a high intensity, short pulse laser. The ultimate sniper weapon, used to "disable" enemy troops. SFHK See,Fire,Hit,Kill. A lightspeed sniper weapon. So in cases like Iraq where our soldiers are fightining guys hiding in buildings over 400 yards away. A Laser weapon will allow you to kill them right when you see them instead of the half second to full second delay in the round arriving at the target. A laser weapon will allow for instant kills.

Originally posted by robertfenix
So AGAIN,
Laser= makes a great sniper weapon
Rail Gun= great penetrator weapon
Neither do much damage though

Using laser for sniping is by no means the best utilization of a laser weapon - although it could certainly bore a smouldering (cauterized) hole through the average human in under a second depending on power/energy level.

Lasers are being developed for air defense, anti-missile, mine-clearing applications, anti-armor & soft vehicles, etc... sniping is way down on the list of effective priority applications of such devices.
Also the chemical laser is generally not compact, considering the chemical fuel that must be carried with it - that is why the push is on for a solid state laser weapon - expect 100kw ss laser weapons by the end of the decade.
Current technology has solid state, diode-based, weapons class lasers at about 35kw. Cooling is the biggest hurdle to overcome right now -

[Edited on 19-5-2004 by intelgurl]

intelgurl u got there b fore me
a rail gun would cause a great amount of damage imagine getting hit by something so fast that by the time u scream the bullets gone and ur limb is missing