Login    Register
User Information
Username:
Password:
We are a free and open
community, all are welcome.
Click here to Register
Sponsored
Who is online

In total there are 52 users online :: 4 registered, 0 hidden and 48 guests


Most users ever online was 155 on Mon Aug 15, 2016 1:40 am

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot] based on users active over the past 5 minutes

The Team
Administrators
Global Moderators
global_moderators.png CS

Plasma power

A place to ask general spud cannon related questions.
Sponsored 
  • Author
    Message

Plasma power

Unread postAuthor: Ragnarok » Mon Dec 24, 2007 12:45 pm

If you've been following the "CO2 tank" thread, I may have caught a little of your attention when I "let slip" that I've been working on a plasma based design, but I suspect that not many people have been following it.

First things first - No, I'm not pissing around, it's a possibility.
It's not a reality yet, still a theory, that's why it's in this section here.

However, the better designs are very complicated, and none are particularly efficient - but you'd better believe they go like greased lightning.
I haven't got any pictures yet, but there are three basic principles I'm considering, all of which have some practicality issues.

I admit the ideas are a bit rough around the edges, I haven't been investing too much thought in the idea so far. If you find holes, I'm not that surprised. It was a half-baked idea that got a bit out of hand, and suddenly seemed feasible a few months back.

Basic heat generation with plasma
This is the simplest idea, simply creating a pressure wave by heating the air in a small chamber with plasma. The temperatures and pressures generated could be very seriously impressive, allowing supersonic velocities from barrels as short as about 4 inches.

For this, the chamber is basically a supercharged camera flash trigger, discharging a few kilojoules of electrical energy through the air in the chamber, giving new meaning to the words "Thunderstorm in a teacup".

Plasma channelling & containment
This is even more powerful, but requires numerous high flux magnets to achieve. This uses magnetic fields to control the plasma created to minimise heat loss, and direct the plasma from the chamber.

More powerful again, and would have an impressive looking muzzle blast.

Gauss/Plasma hybrid
The ultimate design I could come up with.
This would be exceptionally complicated to get to work, but it uses electromagnets to contain a small pocket of plasma within the barrel, and which it catapults along the barrel - completely bypassing the sound barrier. In a large and powerful enough design, this could put a light gas gun to shame on sheer velocity, but it would need a very serious capacitor bank.

Anyway, I'm going to mull over the idea for a few days, and see if I can come up with any more ideas - if you want to do the same, feel welcome.
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Unread postAuthor: ALIHISGREAT » Mon Dec 24, 2007 1:31 pm

ermm yeah i understand it all honest... but seriously it sounds like a very interesting project and a plasma cannon would be very cool. what kind of size would this thing be? and what would you use as the chamber? because it would have to be able to hold alot of pressure.. and one more thing... would it be handheld? ok i was lying... how easy would it be to make one? :)
  • 0

User avatar
ALIHISGREAT
Major General
Major General
 
Posts: 1779
Joined: Sat Aug 25, 2007 6:47 pm
Location: UK
Reputation: 0

Unread postAuthor: DYI » Mon Dec 24, 2007 3:04 pm

What kind of pressure and temperature would we be looking at here Rag?
And when I read that thing about the gauss/plasma cannon hybrid beating a light gas gun for sheer velocity (i.e. >7km/s), I suddenly wanted to build one.

What kind of budget do you think this would require? Because if you can do the more difficult calculations and figure out the more complicated circuitry, I may just be able to build a prototype in the spring/summer. PM me if you're interested.
  • 0

Spudfiles' resident expert on all things that sail through the air at improbable speeds, trailing an incandescent wake of ionized air, dissociated polymers and metal oxides.
User avatar
DYI
Lieutenant General
Lieutenant General
 
Posts: 2861
Joined: Sat Jul 07, 2007 8:18 pm
Location: The People's Republic of Canuckistan
Country: Turks and Caicos Islands (tc)
Reputation: 9

Unread postAuthor: f.c » Mon Dec 24, 2007 3:56 pm

woot. a plasma based gun it sounds amazing, it could start a revolution in spudding.
  • 0

can i be a sasquatch ?
User avatar
f.c
Captain
Captain
 
Posts: 340
Joined: Sun Jul 08, 2007 2:40 am
Reputation: 0

Unread postAuthor: Hotwired » Mon Dec 24, 2007 4:01 pm

  • 0

Last edited by Hotwired on Mon Dec 24, 2007 5:43 pm, edited 3 times in total.
User avatar
Hotwired
Lieutenant General
Lieutenant General
 
Posts: 2599
Joined: Fri Oct 13, 2006 5:51 am
Location: UK
Reputation: 0

Unread postAuthor: rp181 » Mon Dec 24, 2007 4:46 pm

What are you planning to use for the arc? A MOT might work, but i doubt it, but a Marx Generator with MOT(s)?
  • 0

User avatar
rp181
Brigadier General
Brigadier General
 
Posts: 1090
Joined: Thu Dec 13, 2007 8:47 pm
Reputation: 0

Unread postAuthor: jon_89 » Mon Dec 24, 2007 9:45 pm

So let me get this straight. You have a chamber with lets say 100 psi. Then you discharge a camera flash capacitor into it causing it to heat up and make more pressure? This sounds like a very interesting idea.
  • 0


jon_89
Colonel
Colonel
 
Posts: 607
Joined: Wed Apr 11, 2007 9:50 pm
Reputation: 0

Sponsored

Sponsor
 


Unread postAuthor: Hotwired » Tue Dec 25, 2007 4:53 am

A camera flash charging circuit and capacitor discharge system with the voltage multiplied by 100 is more like it :wink:
  • 0

User avatar
Hotwired
Lieutenant General
Lieutenant General
 
Posts: 2599
Joined: Fri Oct 13, 2006 5:51 am
Location: UK
Reputation: 0

Unread postAuthor: carter » Tue Dec 25, 2007 5:03 am

thats wicked. but geez man wouldn't it hurt the wallet.
  • 0

At my lemonade stand I used to give the first glass away free and charge five dollars for the second glass. The refill contained the antidote

carter
Corporal
Corporal
 
Posts: 77
Joined: Mon Mar 05, 2007 2:47 am
Reputation: 0

Unread postAuthor: pizlo » Tue Dec 25, 2007 8:05 am

This is a bit off topic, but very interesting.

My Uncle in town is a senior manager of the University of Rochester's Laser lab, which if i'm not mistaken is the most powerful laser set up in the U.S.

"The OMEGA laser system. OMEGA stands 10 meters tall and is approximately 100 meters in length. This system delivers pulses of laser energy to targets in order to measure the resulting nuclear and fluid dynamic events. OMEGA's 60 laser beams focus up to 40,000 joules of energy onto a target that measures less than 1 millimeter in diameter in approximately one billionth of a second. At LLE scientists continue to research what will one day become a vast source of power using the ocean's ample storehouse of potential energy."

This is just a little info off of there website.
THE POINT: generating plasma is a promising way to produce energy. the only problem is it is only efficient when you get a controlled nuclear reaction.
  • 0

User avatar
pizlo
Brigadier General
Brigadier General
 
Posts: 783
Joined: Fri Dec 22, 2006 7:27 pm
Reputation: 0

Unread postAuthor: Ragnarok » Wed Dec 26, 2007 4:29 pm

@DYI: Well, the gauss/plasma hybrid would require a lot of work, but the basic principle is very simple.

Gauss guns are very powerful relative to even hybrids for their size. A well built but moderate GG can generate a force on the steel projectile equivalent to a few thousand psi.

Take an air rifle. To get 10 to 20 joules of muzzle energy out of it, it needs a barrel of 12 to 24 inches. A gauss gun could do the same in about 2 to 4 inches if it was well built. However, the comparatively heavy projectile limits velocities.

The problem with this is that at low velocities, GGs have low efficiencies of only a few percent. But, as the velocity of the projectile increases, the efficiency of the gauss gun increases. When you hit about 100 m/s or so, the efficiencies become very respectable, of the order of 10% to 20%, increasing further as the velocity rises further. At 300 m/s, 50% or more isn't impossible. The difficulty is reaching this velocity in the first place.

However, if you replace the magnetic projectile with a plasma propellant which is very easily affected by magnetic field, and instead use a comparatively light projectile like an airsoft BB, moderately low energies have a high velocity attached to this, and hitting ultra efficient velocities becomes child's play. Of course, as the plasma is being given extra energy as it's accelerated by the magnetic field, it doesn't have to give up pressure to expand, or build it's own kinetic energy.

If my logic is correct, you could drag a pocket of plasma along the barrel at whatever speed, pushing a light projectile ahead of this. If the projectile fitted the barrel well enough, it wouldn't be impossible to force the system to drive the plasma faster to get even higher velocities.

As for a budget, I'm not sure - it depends on so many things - but it won't be competitive for value against the current varieties of spudgun (based on UK prices for components, but I know they're a lot cheaper in many other countries), of that I can be pretty sure.
Also, bear in mind, beating a LGG with an early prototype would be very hard, there will be things to sort out, and no-one will want to put too much into a huge bells and whistles cannon that would make the sound barrier look pedestrian just yet. I think a couple of hundred m/s would be an good start, and if the sound barrier could be beaten that would be an excellent start and proof of concept.

Won't be a walk in the park, but still, spudding needs some real innovation. Between everyone, we've walked most of the ground between the boundaries of compressed gas, combustion and potential/elastic energy, so I'm going exploring in the twin lands of plasma and electromagnetics.

@ALIHISGREAT: In the second two concepts, magnetics can be used to channel the plasma, minimising the requirements of the chamber. Still, I would still be looking at ceramic tubing for parts to handle both the potential for stray heat, and the requirement of some parts to be non-metallic.

@jon_89: Sort of, but you'd need a LOT more power.
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Unread postAuthor: jon_89 » Wed Dec 26, 2007 4:56 pm

By more power do you mean current or voltage?
  • 0


jon_89
Colonel
Colonel
 
Posts: 607
Joined: Wed Apr 11, 2007 9:50 pm
Reputation: 0

Unread postAuthor: Ragnarok » Wed Dec 26, 2007 4:59 pm

Both more voltage and more energy. The capacitance could probably fall a little without too much difficulty.
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Unread postAuthor: jon_89 » Wed Dec 26, 2007 5:02 pm

Well if it is heat you will be using to get more pressure are there more simple ways to heat the air up? Like a blowtorch or does the temperature change have to be quick?
  • 0


jon_89
Colonel
Colonel
 
Posts: 607
Joined: Wed Apr 11, 2007 9:50 pm
Reputation: 0

Unread postAuthor: Ragnarok » Wed Dec 26, 2007 5:10 pm

jon_89 wrote:Well if it is heat you will be using to get more pressure are there more simple ways to heat the air up? Like a blowtorch or does the temperature change have to be quick?

If I simply wanted to heat the air, I'd build a combustion.
What I want to do is ionise it, because that's what allows you to mess with it magnetically.
  • 0

Does that thing kinda look like a big cat to you?
User avatar
Ragnarok
Chief of Staff
Chief of Staff
 
Posts: 5339
Joined: Tue Dec 19, 2006 8:23 am
Location: The UK
Reputation: 8

Next

Return to General Spud Cannon Related

Who is online

Registered users: Bing [Bot], Google [Bot], MSNbot Media, Yahoo [Bot]

Reputation System ©'