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"Stealth" Plasma Antennas
eldavojohn writes "There's a new antenna that consists of plasma and essentially vanishes when you turn it off. While it may seem to not have many uses in the commercial world, it is very important to military personnel who risk detection or for anybody wishing to avoid signal jamming."
... my neighborhood-association rules already prohibit stealth plasma antennas. :(
How does having the antenna "disappear" effect it's ability to circumvent jamming? The article is apparently being slashdotted as I type this, so I'm just curious.
I got a catholic block.
When I submitted this story, I submitted the story from PhysOrg and I'm not sure why they changed the link. That poor blog didn't stand a chance. I guess they must do that to more randomly distribute their news sources or make it look like they aren't playing host to some PhysOrg worker trying to generate more traffic. Oh well, enjoy a usable link anyhow.
My work here is dung.
If it helps with signal jamming, I want it integrated into my cell phone! What do you mean it doesn't have commercial viability?
--The FNP
I read this in new scientist years ago:
http://www.newscientist.com/article/mg16422141.000-now-you-see-it---.html
(Sorry ham radio nerd humor.)
Disguise it as a stealth-plasma flagpole and proudly fly a red-white-and-blue flaming sheet-o-plasma flag! Has the added advantage of shocking the hell out of any pot-smoking hippies who try to burn it!
Give a man a fish and you have fed him for today. Teach a man to fish, and he'll say "WHERE'S MY FISH, YOU IDIOT?"
you just made something happen by replying in the first place
> Will someone start pulling out the fucking ban hammer on ip ranges?
Just plain doesn't work. You could ban 9/10ths of the internet and still have tards with open proxies via compromised machines in every single remaining IP range.
Even the dept is the same, lazy mods.
'Stealth' Antenna Made Of Gas, Impervious To Jamming Submitted by News Account on 12 November 2007 - 2:58pm. Physics
A new antenna made of plasma (a gas heated to the point that the electrons are ripped free of atoms and molecules) works just like conventional metal antennas, except that it vanishes when you turn it off.
That's important on the battlefield and in other applications where antennas need to be kept out of sight. In addition, unlike metal antennas, the electrical characteristics of a plasma antenna can be rapidly adjusted to counteract signal jamming attempts.
Plasma antennas behave much like solid metal antennas because electrons flow freely in the hot gas, just as they do in metal conductors. But plasmas only exist when the gasses they're made of are very hot. The moment the energy source heating a plasma antenna is shut off, the plasma turns back into a plain old (non conductive) gas. As far as radio signals and antenna detectors go, the antenna effectively disappears when the plasma cools down.
This prototype plasma antenna is stealthy, versatile, and jam-resistant. Credit: T. R. Anderson and I. Alexeff
The antenna design being presented at next week's APS Division of Plasma Physics meeting in Orlando consists of gas-filled tubes reminiscent of neon bulbs. The physicists presenting the design propose that an array of many small plasma elements could lead to a highly versatile antenna that could be reconfigured simply by turning on or off various elements.
- T. R. Anderson and I. Alexeff 2007 APS Division of Plasma Physics annual meeting November 12, 2007
Letter To Iran
So instead of worrying about being jammed, you have to worry about heat seeking missiles. If you are in some place where a single wire will give away your location, I think the heat and light would be easier to notice than the wire.
In a normal antenna, electrons in the metal slosh up and down, accelerated by the electromagnetic fields that it's receiving (or transmitting). In this case, I could use the same description: electrons slosh up and down, driven by the EM fields.
The idea that this could lead to a reconfigurable antenna is a bit farfetched, as it would require that the driving bias electrodes be able to totally float at RF frequencies. Just like a neon sign, or a fluorescent light, you're going to have to keep a large voltage across these to get them to light, so it'll be tricky to use it as a receiving antenna in particular.
Take a look at another project, Talking Lights. This uses conventional fluorescent lights (hey, a plasma!) with a modified ballast to transmit data at serial-link speeds.
The "jam-resistance" doesn't make any sense. If it can receive signals, it can receive signals, period. At the point of the antenna, the desired signal and the jamming signal have already been mixed. The antenna itself can't help you out. (Clever frequency-hopping or other schemes can, though.)
--
Microcontroller kits for the digital generation.
OK, so you don't have a big metal antenna...Instead, you have a big structure built out of evacuated glass tubes resembling Neon tubes.
/frank
And you're going to take this out on the battlefield?
Now, the concept of changing the resonant frequency of the antenna by activating different individual elements is kinda cool, but this doesn't look stealthy at all.
And the worms ate into his brain.
Back in my university days I had the pleasure of being taught by a physicist turned engineer who was actually working on one of these things. The trouble with traditional antennas is their giant radar footprint and traditionally they solved this problem by flopping the antennas up and down when they needed to send signals. Not the most graceful solution so they started looking for alternatives. We had one of the prototypes of these things in the plasma instrumentation lab and it was pretty adept at sending some small signals. The great thing about them is their tunability. Just like any kind of woodwind instrument if you change the length of the tube (imagine a giant piston that's got plasma in it) you change the resonant frequency. My lecturer referred to it as playing the plasma trombone. Good to see these things finally making their way through to practical uses. I was always hoping my crazy lecturer's tinkerings would be used someday.
The Refined Geek - Technology, Finance, Space and everything in between
The original link works for me
'Stealth' Antenna Made Of Gas, Impervious To Jamming
Submitted by News Account on 12 November 2007 - 2:58pm.
Physics
A new antenna made of plasma (a gas heated to the point that the electrons are ripped free of atoms and molecules) works just like conventional metal antennas, except that it vanishes when you turn it off.
That's important on the battlefield and in other applications where antennas need to be kept out of sight. In addition, unlike metal antennas, the electrical characteristics of a plasma antenna can be rapidly adjusted to counteract signal jamming attempts.
Plasma antennas behave much like solid metal antennas because electrons flow freely in the hot gas, just as they do in metal conductors. But plasmas only exist when the gasses they're made of are very hot. The moment the energy source heating a plasma antenna is shut off, the plasma turns back into a plain old (non conductive) gas. As far as radio signals and antenna detectors go, the antenna effectively disappears when the plasma cools down.
Picture:
http://www.scientificblogging.com/files/plasma%20antenna.jpg
This prototype plasma antenna is stealthy, versatile, and jam-resistant. Credit: T. R. Anderson and I. Alexeff
The antenna design being presented at next week's APS Division of Plasma Physics meeting in Orlando consists of gas-filled tubes reminiscent of neon bulbs. The physicists presenting the design propose that an array of many small plasma elements could lead to a highly versatile antenna that could be reconfigured simply by turning on or off various elements.
- T. R. Anderson and I. Alexeff
2007 APS Division of Plasma Physics annual meeting
November 12, 2007
So uhh.. how does this prevent jamming?
Because you have a broader range of frequencies to hop?
[Fuck Beta]
o0t!
You are the reason Slashdot trolls are so pathetic. If you and your kind weren't so "serious business" about every little thing then there would be room for creative trolling.
The pic from TFA looks a bit dainty for combat use. I think a whip antenna is probably still more reliable and has a smaller radar signature for short range communication (IE a couple dozen miles). And the big ones, well, there's no hiding them.
Plus that whole bright and hot thing tends to attract the attention of certain guided missiles and sensor systems...not good! Maybe if they paint the glass or something...at least the light problem is solved.
I reposted the article just above. The picture shows a glowing u-shaped florecent tube. By "disappear" I believe they just mean large radar return. Such materials are called PECs in radar parlance (Perfect Electrical Conductor). You will still be able to see the tube visually.
In related speculation, I wonder if you could use the ION beam from a space probe's thruster (assuming Ion Drive of course) as an antenna. Of course since it wouldn't be parabolic or very directional it might be of limited use.
Letter To Iran
this nice college girl next door is sooo pretty, but i'm too shy to talk with her, i want to listen her conversations and avoid go to jail, sounds nice, where can i buy one kit?.
Rosie O'Donnell much?
Do you even lift?
These aren't the 'roids you're looking for.
Everyone should go out an buy a new plasma antenna before they switch on Feb 17, 2009. After that, your old metal ones will have to have an adapter to work.
Yup totally undetectable, its not like the enemy has the equipment to spot the infrared thrown of by gas heated to super high energy levers or anything. So much harder to see then a metal pole.
Repeal the 17th Amendment TODAY! Also Please Read http://www.gnu.org/philosophy/right-to-read.html
Blogs have moved to open proxy block lists. Then again, implementing that would entail slashdot's development actually accellerating beyond two new features per decade.
Done with slashdot, done with nerds, getting a life.
the internet, serious business
Mmmmmmm...Hot Plasma. This antenna is going to have an amazingly high noise temperature. (Interpretation: it's sort of like trying to use your cell phone right next to an arc welder...that's bad.)
If it needs glass tubes to work, its not like it will just 'dissapear', and would be a lot more fragile than a metal one. That might be ok for light use, but stick it out in the battlefield and i dont see it holding up for long.
Might work disguised as a neon 'eat at joes' lamp for undercover work..
It also mentions needing several 'segments' to prevent jamming. Couldn't this also be done with more traditional antennas?
---- Booth was a patriot ----
Isn't plasma hot? ie:
1. Shoot radar-guided missile
2. Shoot heat-seeking missile
3. ???
4. Kaboom!
So good idea in theory, but hard to put into practical terms. I then guess the large power constraints and the fragility of the plasma are what's keeping this from commercial use. I know there was a post about cell phones using this. When thinking about powering the plasma I guess that gets thrown out the window.
I got a catholic block.
If it is performing as an antenna then it will have the same RF characteristics as a physical antenna and so must be open to jamming.
Engineering is the art of compromise.
If you have seen Britney Spears face reacently, maybe those "sand niggers" as you like to call them maybe on to something
Make SELinux enforcing again!
We were having no luck using an HF radio positioning system. We noticed that everywhere we went in the nearby town we could hear clicking in loudspeakers. We asked one of the locals about it and he told us it was caused by a large military radar. These guys were cranking out so much power that they were creating their own ionosphere (ie. plasma). All the other signals in the vicinity were being absorbed and reflected. You could certainly use this effect to create a large reflector using physically small equipment. For long range radar, the biggest thing is the reflector and that makes it not very portable. This could solve that problem.
This is an old idea. Look in Kraus, Antennas, Third edition. Section 21-29. Also see patent 6657594. The point is the RCS of the antenna is lower when the plasma is off, they efficiency of this type of antenna isn't that high.
This might have a small physical cross-section on radar, but I'm not sure that's enough to compensate for the plasma... ...I work in an electronics lab, and occasionally we use a sputtering system - which generates a ball of plasma to transfer ions from one surface to another. Anyway, point being, when we do this, the guys next door, who do a lot of RF measurements, go absolutely nuts - because we've just screwed all of their instruments and currently-running measurements. (Incidently, between them and the plasma is an inch-thick steel chamber at near-vacuum, plus a thinner steel layer and a reasonably thick wall.)
So sure, it may not look like much when it's off, but it's like a giant pillar of electromagnetic flame when it's on. Still worth it?
Things must be a perishing there....
As someone who designs antennas for fun, This thing would be useful as a transmitting antenna only. The broadband white noise this thing will kick out will easily mask any incomming signal. Furthermore, the noise this thing produces will stand out like a sore thumb for a HARM (High speed Anti Radiation Missle) missle.
Can we apply the stupidity filter to this one as a field trial?
But can I use it for filesharing, and just disappear when the RIAA comes sniffing around?
"It's the height of ridiculousness to say for those 9 lines you get hundreds of millions."
I don't quite get the usefulness of this thing either - when it's turned on, there's bright glowing plasma, and when it's turned off, even though it doesn't have a long metal piece, it still has a lot of metallic support machinery, plus it's a glass tube that you need to haul around carefully instead of a metal antenna or rubber ducky that you can bang into things.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
I am a heat-seeking missile so I am really getting a kick out of these replies...
Who the hell cares about using it for an antenna, when there are millions of aspirant Jedi to sell this to?
Use the force, beyotch!
Sure, it's hard to spot when you turn it off maybe... does that make up for the fact that it looks like it glows like a goddamn spotlight when it's turned on, or am I missing something?
The plasma is contained in a glass, neon light, like tube.
I was picturing a 30-40' foot long spear of flaming hot plasma death that you could turn on your enemies to turn them into smouldering piles of charcoal....and radio in to mom at the same time!!!
...is "Antennae".
Wouldn't the flag already be technically burning? Hippies, 1 You, 0
Everyone who parks their car in NYC and other hostile environments wants an antenna that vanishes when you turn it off. Plasma probably wouldn't jam after a year of use like a retractable antenna, and might even clean the snow off your car, including the pile burying you from the street plows.
--
make install -not war
Well, the "stealth" antenna in the article is a huge, glowing tube. According to the article, the antenna is indeed made of "gas-filled tubes reminiscent of neon bulbs."
I wouldn't call an neon sign "essentially vanishes" when it's turned off.
There's no indication in the article that they can generate the plasma without a confining tube, but even if they could, like the Cheshire cat's grin without the cat, it would still be pretty conspicuous when it's on.
Reminds me of an old cartoon in Computerworld, back in the days when corporations had just standardized on IBM PCs and tried to prevent people from bringing in Macintoshes. An IT inspector is saying to a flunky "Desk, chair, filing cabinet, large glowing chef's hat--nope, no Macintoshes here."
"How to Do Nothing," kids activities, back in print!
Plasma antenna? I'd love to know it's Noise Figure.
Did you think that maybe they might put the neon antenna inside an opaque container? Also, the "stealthy" part refers to it's ability to hide from antenna detectors, not physical inspection.
a vacuum also conducts electricity .Maybe not as well.could they use a vacuum?
Vacuum tubes are cool because some of the stuff they do is still hard to do with semiconductors.
Regarding your sig, Give a man a fish and you have fed him for today. Teach a man to fish, and he'll say "WHERE'S MY FISH, YOU IDIOT?", I like this one too: "Share your fire with a man, he'll be warm for a night. Set him on fire, and he'll be warm for the rest of his life."
The higher the technology, the sharper that two-edged sword.
sounds like it might find application in the area of phased-array radars.
The higher the technology, the sharper that two-edged sword.
If George Lucas taught us anything, it's that these things should make a whum, whum noise as they're moved around plus a kind of white noise crackling whenever they hit things.
That's hardly unobtrusive in a crowd.
I know what those words mean, but that phrase didn't make any sense.
"Nine times out of ten, starting a fire is not the best way to solve the problem." - my wife
Metallic antennas are excited by EM radiation (radio waves) of a proper wavelength. In turn, the antenna will re-radiate (transmit) a tiny bit of that energy, although very weakly, which can be detected. This is totally passive, which is how it is possible to build a passive repeater by simply running a wire between two directional antennas. It is also the general principal of how RFID tags work.
The stealth of this antenna is that it is non-metallic and will not react to EMF when switched off. It has nothing to do with how big the antenna is, or what color it is, or whether or not it emits light, which are all things people have been speculating about.
Dan East
Better known as 318230.
No, because to burn something has to oxidize. Plasma is not an oxidization effect. Hippies 0, him 1
Install a listening device in an embassy meeting room. Records many weeks of conversations. Does not broadcast. Also has a radio receiver.
Prior to an electrical storm, drop a package on the roof using a rapid-descent parachute. It looks like a chimney or AC unit, with a large pole on top that functions as a lightening rod. The box sends a signal to the inside recorder that tells it to broadcast a burst of encrypted data to the box then when lightening hits the pole, it becomes a plasma attenna that can broadcast the data over a long distance. Oh, and the electricity from the lightening powers the whole operation. Then the box self-destructs on the roof.
Seth
$5 / month hosted VPS on linux = awesome!
You cannot post an article with the words "invisible" or "disappear" willy-nilly! You must be precise! Do you know how many salivating geeks are about to be very disappointed by TFA?
(The gas becomes non-conductive when it's off, so it's "invisible" to radar or something like that. The glass tube holding the gas is perfectly visible. It's not like some sort of light-saber thing.)
...has potential military/security potential, vastly ups the chances of you selling a heaping boatload more of your gadgets at a premium price. Just the way it is anymore. "New and improved carbon nanotube security stapler!!" "Concentrated ham n limas in a can, ultra compressed and refined for the long range mission planning of today's warfighter!!" and so on. Read a lot of press releases anymore (I do...) and it seems at least half of them mention some "homeland security" angle that might exist. And it doesn't matter the discipline, archeology to zoology, there's some "defense" related thing can be sold there.
So see, in this instance they get to start with "radio", why yes, we just need lotsa radios for the battlefield total awareness WAN, they get to use the word "stealth", mmm good, everything should be stealthy, "counter jamming", gee whizz they are creaming their pants now, plus "plasma", wow, egghead high tech buzzword angle. If they would have said "marginally effective sort of antenna-thing inside an old used neon sign we snagged", well, it just doesn't sound as good.
I'd love to see that antenna shatter during vibration tests. Any kid with a pellet gun can break that thing, so it sure won't be very useful to anybody nevermind the military.
Excuse me, but please get off my Pennisetum Clandestinum, eh!
prove yours... it doesn't make sense, everyone has to have faith in something. were you there at the beginning or however "million years some idiot scientist makes up on the spot????
I first saw one of these about 8 years ago at a company called CRS. http://www.cfrsi.com/Research/ElectromagneticsPlasmaAntenna.htm
are we any closer to having a real lightsaber?
Anything can, could, and will happen.
These "new" plasma antenna's have been around for 30+ years (explored by both he US and Russia), and they're not 'reminiscent' of neon tubes they are exactly that.. this dude (dr. igor alexeff) uses off the shelf fluorescent bulbs.. I have seen him present on them at least 3x in the last 2 years at conferences. He puts up a convincing argument and does lots of neat tricks with them, but battle-hardening them is quite difficult.
People are confused about these being 'invisible', they are obviously not visually invisible, but when they're not transmitting they have virtually no radar cross-section because non-conductive materials have low reflectivity compared to conductors. As for IR and Visible Light detection, you can put filter materials to block these wavelengths while allowing communications frequencies to transmit (similar to how sunglasses transmit visible light but not UV (and all glasses for that matter-virtually all plastics and glasses are non-transmissive in the UV range). Besides they don't get all that hot compared to other parts of the vehicle (ever touched a large fluorescent bulb? how about the exhaust nozzle on a jet engine?). There are 'hot' plasmas and 'cold' plasmas, in hot plasmas you get the gas conductive by heating the atoms until the electrons are free to move around, in a cold plasmas you inject electrons into the system so you don't have to heat the gas (overly simplistic explanation but it will do), fluorescent bulbs are cold plasmas.
For avoiding jamming the individual tubes are not 'tunable' really, but if you place them in arrays forming, transmitters, reflectors and directors (alexeff has a patent on this) you can turn the different elements off and on to direct the beam and or change sensitive frequencies. However I think avoiding jamming is not a strong point of this design.
The real benefit to plasma antennas (not necessarily this design) is that they are EMP resistant when not activated. The problem with traditional antennas is that they receive even when turned off and provide a convenient path for EMP to get inside otherwise hardened electronics.
However, despite the pros of this design they are not really feasible (fragile, bulky, noisy and limited power handling capability) and they have received far more attention in this thread than in any of the scientific/military circles because there are much more effective antenna systems.
If you want to read the pros of his systems read some of his conference papers and patents, but he never mentions the cons at all:
http://scholar.google.com/scholar?as_q=&num=10&btnG=Search+Scholar&as_epq=plasma+antenna+&as_oq=&as_eq=&as_occt=any&as_sauthors=I+Alexeff&as_publication=&as_ylo=&as_yhi=&as_allsubj=all&hl=en&lr=&safe=off
Slashdot already blocks Tor exit nodes. I'm not sure if they're using a DNSBL or other spam list, but I don't think they're actively scanning. This list might include other open proxies; I'm not going to bother to check, to be honest. Slashdot also has restrictions on the number of posts you can make from a certain IP address (or user account, if you're logged in), so if you make more than a couple posts, you're not going to be able to post again, and, chances are, if you're using a popular open proxy, you're going to get blocked anyway because someone else will post before you do.
It wouldn't be very hard to spam the shit out of Slashdot, though. You can do it with user accounts or anonymously. Write a simple script to get a list of recently checked proxies from all of the popular lists, or write your own scanner to get a zero-day list for yourself. Or just get one of the many script kiddie tools that are available for both of those tasks. Then you have an ulimited array of options. One thing I've been thinking about doing (not for spamming Slashdot, mind you) is setting up a server (sort of in the vein of those old IRC flood bot scripts, but with a DDoS network twist) that'll connect to a few hundred proxies, with a single client interface you can manipulate to get a random proxy on each connection. All you need to do then is open a few tabs and a couple of browsers. You could also write a script to just do it automagically.
Of course, if you're a new age script kid, you'll already have access to a few hundred (or maybe even thousand) Windows nodes running Sub7 or PhaggotBot or whatever the newest trend is, and you could always just use those, too. And this doesn't work on Slashdot, for reasons mentioned above, but there's a lazy man's method to spamming, too: just fire up about 20-30 instances of Tor (edit the torrc to change the listening port number) and connect from IE, Opera, and Firefox. Reload whichever Tor server you happen to be using at the moment to try to get a new exit path. There's probably a better method for that, but I haven't looked into that either.
And then there's the method with the account. This is probably even easier, really. I'm not sure if Slashdot limits the number of times you can post from one IP address even if you're logged in, but it might. Nevertheless, we can still have some fun with this. Just make a bunch of accounts. Who doesn't have access to a mailserver? Register a few domains (who doesn't already have several?), set up wild-card forwarding or something like that, then make a few dozen accounts. Write a script to handle the cookies, and maybe attach another client interface so you can spam whatever you feel like (instead of having a bot automagically spam, although you could make a big list of posts for the bot to randomly choose from).
Tie that into the open proxy / Botnet / Tor method as necessary.
Disclaimer: No, I'm not a spammer.
Anybody else thinking lightsaber? (Yeah, I'm jacking the thread, but it's not been mentioned yet.)
Linux, you magnificent bastard, I read the fucking manual!
If it's plasma, it's heated. Heat is highly visible to anyone using thermal imaging goggles on the ground, or in the air. Thus, not stealth.
The only thing you are jacking is your tiny pecker.
I for one welcome our new stealth-antennae-bearing overlords. Oh wait...
So, it 'vanishes' when it is off? When it is on it lights up like a neon sign? I could be wrong - but a gigantic neon light antenna up in the air is going to be a pretty obvious target. The enemy is going to know exactly where you are. Also - they are going to know you are transmitting something - so they can start to jam/home in on your signal. How exactly does this prevent that?
Also - I would love it if the enemy used this brilliant antenna design. You will be left flabber"gas"ted as I use my ultra-portable, ultra-stealthy jamming device to explode your plasma tubes on the battlefield. What is my weapon? A rock and a slingshot. My eyes! The goggles do nothing!
I remember seeing this stuff more than 10 years ago. Being Australian the stuff I saw ten years ago was from an Australian University grant from the DSTO (military research organisation), with information that can be found at http://wwwrsphysse.anu.edu.au/~ggb112/
In fact a Typical Fluroscent tube makes a reasonable HF antenna with its frequency dependent on its length. For those that think the glowing plasma makes the antenna detectable in the visible spectrum, its easy to have a material that is opaque in the visible spectrum but transparent in the radio spectrum. A piece of stryofoam is enough to do the job.
D.
In my mind, if you sell to the military, it's still commerce.
That was my very first thought too: if this is for military use anyway, then quit dicking around with making antennas and get busy on those sabers already! ;)
"Good news, everyone!"
Posting just to blow away accidental moderation. Is there any other way to undo a moderation?