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Magnetic Propulsion Pellet Gun Achieves 20km/s
"Researchers at Sandia National Laboratories have used their Z Accelerator, a magnetic accelerator used in equations of state research, to accelerate pellets to speeds of about 20 km/s (about twenty times faster than a high-powered rifle bullet). Full story is here." Uses projected for this technology include simulating the impact of space junk, and, Yes, as the core of a hyper-velocity weapon.
Miltary equipment is EMP hardened. I don't think this would be an option. EMPs probably serve best as a strike against civilian life and "public order".
...this is one of the best ways known to get material off the moon. Required energy (and hence barrel length) is much lower, and there's no atmosphere to cause problems.
I'm assuming you mean the Z-pinch machine, not magnetic launchers in general.
I mean magnetic launchers in general (actually, gun-like launchers in general; magnetic just happens to be one of the more convenient forms).
You can access the full text here if you have a subscription. Unfortunately I don't understand their technique. Can you explain it to us ?
:).
Possibly. If I had a subscription
So, while the projectile is propelled by a magnetic field in both cases, a "rail" gun uses a specific method (rails+ conductive armature) to generate the field. For more information see railgun.org
What are you talking about? This sounds nothing like what a true rail gun is because it is nothing like what a rail gun is.
I think one other thing that might be fairly interesting is the fact that they could use this to send items into permanent orbit around the earth. As I learned in Physics class, all that is needed is a velocity of 8km/s and Then I can send an object into orbit around the earth (This is true because of the effects of gravity vs. the slope of the earth would maintain the orbit). So, if we can have the pellets going at 20 km/s What will they do when they can get bigger things going at this velocity?
Uhh, make me. I know more about aerodynamics than any three people you've ever met.
Why yes, I AM a rocket scientist!
I don't think this would make a very good Zero-G weapon. Momentum would have to be conserved in the firing of a pellet. If you fired a small pellet at 20 km/s the person firing it would feel a pretty big recoil.
If the pellet is 2 grams and the person firing it is about 100 kg (with equipment and the gun), then the person would have a velocity of 40 m/s in the direction opposite of the pellet. That's a heck of an acceleration for a person to undergo.
Perhaps you could mount it on a space station, but it would still probably give the space staton a pretty good jolt.
provolt
Not really...it depends on what you are hunting. If you are going for a single large animal, this would take him down quickly before he could react to the sound. Just don't miss...and make sure of a couple things, 1) that you've got a mountain behind your shot to stop the projectile and 2) that some hunter isn't going to kick your butt for scaring all the other animals away.
TheGeek
TheGeek
http://www.geekrights.org
Kill the monkey
This would also make a good weapon in a Zero-G environment, again, no chemical reaction required.
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crazy dynamite monkey
I wonder if they could scale this up to shoot payloads into orbit? With a relatively low trajectory they could concievably build a long enough barrel to prevent acceleration from damaging the cargo. Probably would flatten a human but maybe not hurt computer hardware, or fuel, or O2, H2O or other necessary supplies.
-Moondog
Same to you. =)
You're just realizing that you've been hit that the bullet is already 20 km away. That IS scary.
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Je t'aime Stéphanie
African or European?
Nothing to see here. Move along.
Could this shoot down incoming nukes?
Assuming the aiming problems can be overcome, yes. Sorta. The biggest problem with this is that if I'm going to nuke some city and I think they have anti-missile defenses, I will detonate a high altitude burst to generate an EMP, disabling most defenses you might have. Then (shortly) will follow the real attack. The EMP burst can be done in low orbit, putting it probably out of the reach of most anti-missile defenses.
There are a ton of other ways, most cheaper than that, for getting around or disabling anti-nuke defenses.
could this become a feasable way to get pico-satelites in orbit?
Well, maybe. Have you ever seen a meteor? That's what hapens when a gravel or sand sized particle hits the upper atmosphere at 20 - 70 km per sec. If you could shield it enough it might work. There are probably some serious engineering issues to overcome to make it practical, though.
"Bite me, it's fun!" - Crowe T. Robot
Basically, this sounds like the concept of a rail gun. There was a group (military?) a while back that supposedly demoed such a weapon, but in fact rigged the target with explosives to make it "more spectacular"...
rm
Sci-Fi Storm
Anon. Cow. - You are the rude asshole. Ablative technology is one of the key historical reasons for our comparative success as a space power, at least he can discuss something highly technical at an intellectual level, without resorting to the kind of histrionics, and bullcrap pseudo intellectual nonsense you tend to put in these pages just praying to get 1 insightful per week. Cut the personal crap or get out yourself. And BTW if you can't get insightful, try a little harder for funny the ... pitiful thought and understanding you put into posts is pretty ugly.
Sarcasm will get you nowhere jerk.
Anon. Cow. : At it again are we? Get a clue, and try to make some useful comment, esp. if you are going to spend 8+ hours in here/day (probably can't get a real job.... so let's insult every other person on the planet) .... So he's ultranationalist/facist to think of the applications of a system in the context of the defense of the nation which gives assholes like you the freedom to go around and slam every thoughtful person in the place??? Whats that make you? a slimebag draft dodger?, a creeping socialist? a very large oedipal complex waiting to happen? or just an asshole?
On the original post:
Interestingly satellites are a great application of the technology as a weapon, but you would have to lead the target... quite a bit ;-)
Terrorists best use of satellites are to buy through shell corps. imagery from the new 1M class of commercial birds. So... if you shoot the terrorists bird, you also shot your own commercial bird, and despite Anon. Cow.s posts it is MNC's who have enough money and clout (against the advice of the DoD, but with the support of congress) to launch 1M recon sats (not the DoD) which are the real threat to us. Yeah the 1M stuff is of vast commercial utility, but the potential for misuse is also HUGE!!! even moreso than it is for the black agencies who control the birds now.
Another use as you site is to launch small/micro satellites. Take a look at the AFRL site for MightySats and you will get the idea on the unclassified state of the practice for birds. You can make some extrapolations on the size of rail gun you might need to launch something large enough. Begins to be impractical for several reasons, but that is for another post. Suffice it to say you could launch a very small object into orbit, but at what size vs. mission is the satellite useful.
mdw ;-)
It's not really a railgun, but for a neophyte the principle is sufficiently similar. Hopefully not too many people will rail on folks who tend to confuse the two.
Hello, actually, the hole in the tip of a hollow point bullet is more for weight distribution and explosive expansion than an aerodynamic effect. In a bullet, the more weight that you can move back towards the rear (thicker) part of the bullet, the better the bullets stability, that's one reason why almost all "match grade" rifle bullets are "Spitzer boat tails". Another reason for boattails is that the reduction in the base (trailing) edge of the bullet reduces drag to some extent. There is actually a "new" (about 15 years old) style of bullet called a "ballistic tip" (T.M. Nosler) that is basically a hollowpoint bullet with a hard delrin insert in the tip that makes it have the aerodynamics of a "spitzer" type bullet (most full metal jacket rifle bullets are spitzers, for the shape think 1950's era "rocket ships")but the weight distribution of a boattail hollowpoint. Also, in response to "kotetsu", almost all military electronic weapon systems are EMP shielded, that's one of the reasons why they are so damn expensive (not to mention kickbacks and other hiddens). EMP would only seriously affect the civilian populace, an M-1a tank for example can withstand EMP from a ~250 MT nuclear blast, but obviously not the blast itself. S.
"Laws are like sausages, it is best not to see them being made" Otto Von Bismarck
Oh Yeah? What if I've met you and know 2 other smart types! ;)
"Laws are like sausages, it is best not to see them being made" Otto Von Bismarck
...in Riff's arsenal. You paying attention, Pete?
Seriously, at 20000m/s, that would probably sound-off like a siren. Probably not suitable for hunting.
Thus sprach DrQu+xum.
DrQu+xum: Proof that the lameness filter doesn't work.
The paper mentioned in the article is Journal of Applied Physics Vol. 89, No. 3, pp. 1625-- 1633, 1 February 2001. You can access the full text here if you have a subscription. Unfortunately I don't understand their technique. Can you explain it to us ?
I can email you the PDF if you like. You can find my email address in my user info.
Now I've got to figure out how to get a potato gun to shoot at 20Km/sec. What's the escape velocity of a potato anyway?
I remember seeing a bit on a railgun on some show on the discovery channel that impressed me. I don't remember any of the specifics, but I remember them showing what a very oddly shaped projectile did to a block of steel that looked to be about 6" thick. Simply put the hole through it appeared to be roughly twice the diameter of the projectile. To me that's a very impressive display of kinetic energy.
Question everything
I'm tired of you commie pinkos trying to tell me which guns I can and can't have. "Being necessary to the security of a free state, the right to bear arms shall not be infringed." --2nd Amendment. So, in short, you soy eating, godless, Church of Satan youth basketball Nite league playing, primitive, reefer smoking, hippy screwheads can just suck my boom stick. I'm going to hunt with whatever the hell I want, as is my God given right (at least if Moses and the NRA have anything to say about it).
--Jimmy has fancy plans; and pants to match.
I would imagine that at 20 km/s, you might see a nice glow. I suppose the ambient light in the day time would probably wash it out, but at night I would think it would be quite a site.
--Jimmy has fancy plans; and pants to match.
No, it's not a railgun. Neither is what your talking about. That is a coilgun.
- dave f.
That would be redundant. It already says the right of the people to keep and bear arms. This includes hyper-velocity railguns, AK47s, and muzzle loaders. Of course, it's not very practical to own a railgun now is it. I reckon they're a bit expensive.
nemo me impune lacessit
I don't know about that... I've read that an EMP strike could take out most of our airforce, while the old USSR fighter-planes, which still used vacuum tubes, would servive to fight a post-apocolyptic war.
Are we surprised? When are we going to go metric, anyway?
BTW, to put something orbit, you wouldn't necessarily have to get the mass all the way there in one shot - just give it a boost. If we could develop a large magentic gun to boost the rocket on its way, we use less chemical fuel and hence can carry a larger actual payload.
You would have to detonate within a reasonable distance for EMP to disable anything. This system reaches 3 times escape velocity. It can hit anything within line of sight long before it got close enough to be dangerous. This thing could take out geosynchronous satelites.
"If there is nothing you are willing to die for, then you are not really alive." Myself
I have a better idea, bring a large one into space and use it to launch huge barrels of trash out of our orbit and towards the sun...or maybe not...but i think it would like to shoot mr gates into an eternal 20km/s trip through space.
"worst episode ever"
I'm not sure I understand the physics of that. We cool off in air (on a hot day, or in the breeze) because the sweat evaporates from our skin, carrying off heat. Bullets don't sweat, and aren't moist. The moving air itself could carry off heat, but a normal bullet is hot because the air is moving past it fast enough to heat it by friction. I would guess then that the air in the cavity isn't leaving the cavity, and moving "slowley" inside, or vibrating (sound wave). Was that the idea?
could this become a feasable way to get pico-satelites in orbit? It sounds like, with further testing, they can get even acceleration that doesn't do too much damage to the pellet.
oh, one more thing, where can I get one? :)
one more thing: technilogical superiority because you've got the fastest gun? there are many other things to consider, most of which the US does have, but this gun isn't THAT significant, I don't think.
--
spam spam spam spam spam spam
No one expects the Spammish Repetition!
Scientists restrict study to entire physical universe; creationist
Hey I have an idea. you can use this thing like the Galeilio telescope, fire this sucker up with a chemical rocket, then lit her rip in space. The only thing I see as a problem is that there might be a power shortage.. um probably more problems...
That reminds me of "Jay's" cricket gun from MIB. Small and simple but boy does that little bugger have one mighty kick! See www.meninblack.com for more details.
Buzz Off
"A well-regulated Militia being necessary to the security of a free State, the right of the people to keep and bear hyper-veolcity railguns shall not be infringed."
I've seen a detailed proposal for a 15g man rated coilgun capable of launching 1 ton into (very) LEO. It's a 250 mile long fiberglass vacuum tube surrounded by a electromagnets. A launch takes 15GW of electrical power for about 30 seconds. The passenger rides in a crash couch (obviously at 15g) in front of a superconducting coil. For the first 25s, the thrust is forwards. For the next 5s the thrust is upwards, as the end of the gun bends up a convenient mountain. Shortly before the payload reaches them, the muzzle doors open, and the thrust is then backwards (air resistance) for the few seconds it takes to clear most of the atmosphere. Aerodynamic control surfaces on the projectile bend the orbit into an ellipse whose perigee just grazes the atmosphere, with apogee just above. Finally a very small rocket firing 45 minutes later raises the perigee to stabilize the orbit long enough for pickup by an inter-orbital shuttle.
It seemed a completely plausible design, although the failure mode analysis was likely to be tricky.
I can email you the PDF if you like. You can find my email address in my user info.
Sent a day ago, and still waiting. Was it eaten by the 'net daemons?
If necessary, you can find my email address in the Linux Media Labs web-board (http://www.linuxmedialabs.com and hunt around).
Could anyone with closer ties to this project brief me on exactly what the working principles of this are? The article doesn't go into very much detail.
Before I get six different descriptions of how railguns work - I already know how most varieties of magnetic gun work. I want to know *which* this uses.
My best guess is something that uses the same principles as a coilgun (conducting object is repelled by the rapidly changing magnetic field), but the article still doesn't go into enough detail to confirm this.
Earth escape velocity is ~7 MILES/second or ~ 11.3 KILOMETERS/second. But the officials at our national lab says in the article that it is 7 KILOMETERS/second and then goes on to use that to show just how fast this thing is...
Perhaps they meant the velocity required to attain orbit; this is about 8 km/sec.
The current wording if enough. After all, the founding fathers knew that weaponry would change over time.
LK
"Hi. This is my friend, Jack Shit, and you don't know him." - Lord Kano
Because. We're talking about a small pellet here.. to send anything of size this would have to be orders of magnitude larger. See other posters who discuss this.
How about we consider using this device (or a modified version of it) for sending materials into low Earth orbit? It would be a lot cheaper than sending them up via rocket or space shuttle. Gathering materials in low orbit isn't a major problem (assuming they aren't moving too fast.) People (or anything else living) would have to go conventionally. It'd be like airlines being able to fly your luggage there for pennies on the pound, but you costing quite a bit more.
So long and thanks for all the fish . . . !!!
Next thing we'll know, this thing's gonna get stolen and we'll be seeing a psycho hanging around night clubs waiting for 50+ people to get in line, then FOOM! 50+ victims in one bullet.. The fallacy of ever-improving weaponry is that the guys holding the trigger (or worse, the funding) just don't get smarter. Now I'm all for research and I can imagine this has plenty of other uses besides railguns (small spacecraft launches perhaps), but people are still people, smart, dumb, genius, psycho, whatever. Some 21st century Saddam Hussein will find a way to make us regret this evolution, it's only a matter of time.
-Billco, Fnarg.com
Earth escape velocity is ~7 MILES/second or ~ 11.3 KILOMETERS/second. But the officials at our national lab says in the article that it is 7 KILOMETERS/second and then goes on to use that to show just how fast this thing is...
Maybe I'm being too picky but it does make them look like idiots when they don't do trivial fact checking.
(I've been forwarded a copy of the research paper, so here's how this thing really works.)
Ok. The Journal of Applied Physics article (Feb. 2001) does not describe this as a "gun" at all.
The device uses the Z-machine current source to send a large amount of current through two concentric pipes that are connected at one end. Current goes up the outer pipe and down the inner one.
This sets up a very strong magnetic field between the pipes, which pushes the two pipes apart (crushing the inner one and pushing outwards on the outer one). This is the same kind of effect that you get in a loop of wire that carries current (motor principle).
Samples on plates are stuck to the sides of the outer pipe. Magnetic forces accelerate these plates outwards rapidly, and the samples deform. This deformation is measured, giving a lot of useful materials information (the purpose of the experiment).
It's unclear from the article whether the plates, the samples, or neither go flying. The velocity quote is probably just the maximum velocity achieved while the pipe is expanding outwards under pressure. Letting the plates fly would give a somewhat better experiment, but would cause practical problems (they'd destroy whatever part of the machine they finally smacked into).
Physics-wise, this works on exactly the same principles as a railgun (motor principle with DC current). It's optimized for pressure experiments, not for firing projectiles; you could probably build a railgun that was more efficient at the second task.
Inductive effects do occur (this is a short current pulse), but are considered a source of error in the experiment, and so presumably aren't the dominant effect.
This or any of a number of other magnetic cannon techniques could work, or even a compressed gas gun (like the "Super Gun" from years ago).
The problems are twofold:
To reach orbit, you need an energy of about 30 MJ/kg (for a velocity of about 8 km/sec). Energy is force (mass times acceleration) times distance, so for a given acceleration, you can calculate the barrel length of the gun required. For a 3g accelerator for humans, you get a gun 1000 km long. If you can overcome the engineering problems and build a gun that accelerates cargo at *3000* gravities... you still have a gun 1 km long (about 0.62 miles, if you were wondering).
This can be built, but it's *expensive*. There would have to be a very strong incentive to build it, and amortizing the cost of the gun will raise your launch costs by quite a bit.
You'll notice that the experiment discussed in the article was done in vacuum.
Your gun will have to have an enclosed barrel (even if it's a magnetic gun). Otherwise, the mach-16 sonic boom will tear the firing coils off their mountings or otherwise harm the gun's structure.
Your gun (and anything near it!) is still going to have a lot of wear from the effects of a hypersonic projectile smacking into the atmosphere on leaving its muzzle.
Lastly, your projectile is going to have to have shielding around it to keep it from burning up while leaving the atmosphere. This will add weight to the projectile, and require a higher muzzle velocity (because the projectile will slow down).
All of these problems are manageable, but they increase the cost of the gun and the cost per kilogram of payload even more.
In summary, yes, we can scale up this and other guns like it; however, they're a royal pain to build and use, and there isn't enough demand at present to make them practical.
OTOH, this is one of the best ways known to get material off the moon. Required energy (and hence barrel length) is much lower, and there's no atmosphere to cause problems.
About time?!
What percent of the federal budget do you think is spent on 'defense'?
--
Soma: because a gramme is better than a damn.
Now I know why there is an energy crisis in California.
BTW, this DOESN'T sound like a rail gun. A rail gun uses a series of magnets to propel a projectile. This sounds like it uses one rapidly expanding magnetic field.