Lightning Projectors and Railguns without Rails?

[MrSamosa]

I am taking my first year of Physics this year; it's general Physics. As I'm sure many of you can relate, you might not have done so hot your first time around at Physics...anyhow, we just finished up the "Electricity and Magnetism" unit, and it has really struck my interest in the way Chemistry did, to the point that I am spending much of my free time trying to find more information on it or dabbling around in my "lab." Nevertheless, some of what I'm speculating about may not be completely accurate, so please correct me :)

The other day I came across a website for a company who has patented a new kind of stun gun. Their name is HSV Technologies ( http://www.hsvt.org ) and they boast that their technology can project a current up to 2 km away (not theirs specifically, but they link to an article where another group of researchers did that). It takes advantage of photoionization of the air via UV lasers, creating 2 conducting channels through the air. This same technology was used in Japan a few years ago to trigger lightning strikes; in this case, the user is creating the lightning to strike down enemies :P .

Now, that in itself is really cool. But then it got me thinking about the old idea of railguns and their omnipresent problem of rail corrosion. Why not get rid of the rails entirely and replace them with ionized channels of air? I don't know what kinds of possiblities this would open or if it would be possible at all, but it's been on my mind and I want someone else's input on the idea.

[MrSamosa]

I am taking my first year of Physics this year; it's general Physics. As I'm sure many of you can relate, you might not have done so hot your first time around at Physics...anyhow, we just finished up the "Electricity and Magnetism" unit, and it has really struck my interest in the way Chemistry did, to the point that I am spending much of my free time trying to find more information on it or dabbling around in my "lab." Nevertheless, some of what I'm speculating about may not be completely accurate, so please correct me :)

The other day I came across a website for a company who has patented a new kind of stun gun. Their name is HSV Technologies ( http://www.hsvt.org ) and they boast that their technology can project a current up to 2 km away (not theirs specifically, but they link to an article where another group of researchers did that). It takes advantage of photoionization of the air via UV lasers, creating 2 conducting channels through the air. This same technology was used in Japan a few years ago to trigger lightning strikes; in this case, the user is creating the lightning to strike down enemies :P .

Now, that in itself is really cool. But then it got me thinking about the old idea of railguns and their omnipresent problem of rail corrosion. Why not get rid of the rails entirely and replace them with ionized channels of air? I don't know what kinds of possiblities this would open or if it would be possible at all, but it's been on my mind and I want someone else's input on the idea.

[MrSamosa]

I am taking my first year of Physics this year; it's general Physics. As I'm sure many of you can relate, you might not have done so hot your first time around at Physics...anyhow, we just finished up the "Electricity and Magnetism" unit, and it has really struck my interest in the way Chemistry did, to the point that I am spending much of my free time trying to find more information on it or dabbling around in my "lab." Nevertheless, some of what I'm speculating about may not be completely accurate, so please correct me :)

The other day I came across a website for a company who has patented a new kind of stun gun. Their name is HSV Technologies ( http://www.hsvt.org ) and they boast that their technology can project a current up to 2 km away (not theirs specifically, but they link to an article where another group of researchers did that). It takes advantage of photoionization of the air via UV lasers, creating 2 conducting channels through the air. This same technology was used in Japan a few years ago to trigger lightning strikes; in this case, the user is creating the lightning to strike down enemies :P .

Now, that in itself is really cool. But then it got me thinking about the old idea of railguns and their omnipresent problem of rail corrosion. Why not get rid of the rails entirely and replace them with ionized channels of air? I don't know what kinds of possiblities this would open or if it would be possible at all, but it's been on my mind and I want someone else's input on the idea.

[DirtyDan]

The problem there is that railguns take advantage of the magnetic properties of materials; in other words, unless these beams of ionized air ferromagnetic, your are not going to achieve any acceleration. Now, I would not mind toying with some lasers my self... What medium were they? CO2? I'll have to check that out :)

[DirtyDan]

The problem there is that railguns take advantage of the magnetic properties of materials; in other words, unless these beams of ionized air ferromagnetic, your are not going to achieve any acceleration. Now, I would not mind toying with some lasers my self... What medium were they? CO2? I'll have to check that out :)

[DirtyDan]

The problem there is that railguns take advantage of the magnetic properties of materials; in other words, unless these beams of ionized air ferromagnetic, your are not going to achieve any acceleration. Now, I would not mind toying with some lasers my self... What medium were they? CO2? I'll have to check that out :)

[rational611]

HSV Technologies and their product has been discussed before on this forum. You might take a look at http://roguesci.org/theforum/showthread.php?t=4419&highlight=remote+stun+gun
Please post about any new developments that have taken place since.

[rational611]

HSV Technologies and their product has been discussed before on this forum. You might take a look at http://roguesci.org/theforum/showthread.php?t=4419&highlight=remote+stun+gun
Please post about any new developments that have taken place since.

[rational611]

HSV Technologies and their product has been discussed before on this forum. You might take a look at http://roguesci.org/theforum/showthread.php?t=4419&highlight=remote+stun+gun
Please post about any new developments that have taken place since.

[MrSamosa]

This doesn't concern tasers or stunguns so much, but is expanding on the idea of using ionized air channels to conduct a current.

Could the said channels be used as "rails" for a railgun, assuming that the projectile could temporarily counteract the force of gravity. The advantage here is that there wouldn't be physical rails that would warp and weld with repeated firings, thus keeping costs down in the long run. Furthermore, the rails could be indefinitely long, depending on how long the projectile resists gravity and how far the current travels--meaning the force on the projectile is applied over a much longer distance, allowing for much higher speeds.

[MrSamosa]

This doesn't concern tasers or stunguns so much, but is expanding on the idea of using ionized air channels to conduct a current.

Could the said channels be used as "rails" for a railgun, assuming that the projectile could temporarily counteract the force of gravity. The advantage here is that there wouldn't be physical rails that would warp and weld with repeated firings, thus keeping costs down in the long run. Furthermore, the rails could be indefinitely long, depending on how long the projectile resists gravity and how far the current travels--meaning the force on the projectile is applied over a much longer distance, allowing for much higher speeds.

[MrSamosa]

This doesn't concern tasers or stunguns so much, but is expanding on the idea of using ionized air channels to conduct a current.

Could the said channels be used as "rails" for a railgun, assuming that the projectile could temporarily counteract the force of gravity. The advantage here is that there wouldn't be physical rails that would warp and weld with repeated firings, thus keeping costs down in the long run. Furthermore, the rails could be indefinitely long, depending on how long the projectile resists gravity and how far the current travels--meaning the force on the projectile is applied over a much longer distance, allowing for much higher speeds.

[Silentnite]

I don't think that this is exactly feasible, at least not from your typical at home experimenter. Given that your trying to make air into something that metal could follow along for a said amount of time for a said path...

The way the Stun gun works (IMO) is the lasers orient the air in a current passing way. It wouldn't make it solid, and you could more than likely pass straight through without any hinderance if the current was off.

So how that could transfer to a railgun approach beats the hell out of me. Maybe ask your teacher to revisit the subject.

[Silentnite]

I don't think that this is exactly feasible, at least not from your typical at home experimenter. Given that your trying to make air into something that metal could follow along for a said amount of time for a said path...

The way the Stun gun works (IMO) is the lasers orient the air in a current passing way. It wouldn't make it solid, and you could more than likely pass straight through without any hinderance if the current was off.

So how that could transfer to a railgun approach beats the hell out of me. Maybe ask your teacher to revisit the subject.

[Silentnite]

I don't think that this is exactly feasible, at least not from your typical at home experimenter. Given that your trying to make air into something that metal could follow along for a said amount of time for a said path...

The way the Stun gun works (IMO) is the lasers orient the air in a current passing way. It wouldn't make it solid, and you could more than likely pass straight through without any hinderance if the current was off.

So how that could transfer to a railgun approach beats the hell out of me. Maybe ask your teacher to revisit the subject.

[MrSamosa]

My logic is that the resistance of a metal armature would be significantly less than that of the ionized air channel, so more current would flow through it instead of the rest of the way down the channel. Think of it the same way as the stun-gun design, only instead of the current passing through an attacker's body, it goes through the metal armature and back to the gun via the other channel. Of course, such a design would be very vulnerable to weather conditions--a high wind could be all it takes to knock the armature from between the "rails."

It wouldn't be feasible for the hobbyist, but it still seems like a fun idea.

[MrSamosa]

My logic is that the resistance of a metal armature would be significantly less than that of the ionized air channel, so more current would flow through it instead of the rest of the way down the channel. Think of it the same way as the stun-gun design, only instead of the current passing through an attacker's body, it goes through the metal armature and back to the gun via the other channel. Of course, such a design would be very vulnerable to weather conditions--a high wind could be all it takes to knock the armature from between the "rails."

It wouldn't be feasible for the hobbyist, but it still seems like a fun idea.

[MrSamosa]

My logic is that the resistance of a metal armature would be significantly less than that of the ionized air channel, so more current would flow through it instead of the rest of the way down the channel. Think of it the same way as the stun-gun design, only instead of the current passing through an attacker's body, it goes through the metal armature and back to the gun via the other channel. Of course, such a design would be very vulnerable to weather conditions--a high wind could be all it takes to knock the armature from between the "rails."

It wouldn't be feasible for the hobbyist, but it still seems like a fun idea.

[James]

How about a railgun with four rails. Two lower ceramic rails to hold the slug up. Two ionized air rails to convey the charge.

[James]

How about a railgun with four rails. Two lower ceramic rails to hold the slug up. Two ionized air rails to convey the charge.

[James]

How about a railgun with four rails. Two lower ceramic rails to hold the slug up. Two ionized air rails to convey the charge.

[Jacks Complete]

The big issue with railguns is the force applied to the armature is the same as the force applied outwards to the rails. They all try to move away from each other. This means that when your slug goes out at 5kmps, the rails get seriously bent.

Copper is used for the rails, but copper is soft. Try silver or aluminum, and they are still soft. There isn't anything strong, like steel, that conducts well enough. Also, you have to make a sort of weird barrel, since two sides have to be insulated, so current only flows throguh the projectile. This causes all sorts of issues with high strength ceramics and plastics - but the plastics ablate badly, and the ceramics shatter. There isn't anything strong, like steel, that doesn't conduct. :(

Further, to build a railgun in the UK you would need an FAC once it got above 1 joule! Bastards.

[Jacks Complete]

The big issue with railguns is the force applied to the armature is the same as the force applied outwards to the rails. They all try to move away from each other. This means that when your slug goes out at 5kmps, the rails get seriously bent.

Copper is used for the rails, but copper is soft. Try silver or aluminum, and they are still soft. There isn't anything strong, like steel, that conducts well enough. Also, you have to make a sort of weird barrel, since two sides have to be insulated, so current only flows throguh the projectile. This causes all sorts of issues with high strength ceramics and plastics - but the plastics ablate badly, and the ceramics shatter. There isn't anything strong, like steel, that doesn't conduct. :(

Further, to build a railgun in the UK you would need an FAC once it got above 1 joule! Bastards.

[Jacks Complete]

The big issue with railguns is the force applied to the armature is the same as the force applied outwards to the rails. They all try to move away from each other. This means that when your slug goes out at 5kmps, the rails get seriously bent.

Copper is used for the rails, but copper is soft. Try silver or aluminum, and they are still soft. There isn't anything strong, like steel, that conducts well enough. Also, you have to make a sort of weird barrel, since two sides have to be insulated, so current only flows throguh the projectile. This causes all sorts of issues with high strength ceramics and plastics - but the plastics ablate badly, and the ceramics shatter. There isn't anything strong, like steel, that doesn't conduct. :(

Further, to build a railgun in the UK you would need an FAC once it got above 1 joule! Bastards.