back to article New gizmo means working electropulse rayguns at last

American boffins say they have developed a new and more powerful magnetron - a device used to produce microwaves - and that the day of the long-awaited, circuitry-frying electropulse raygun may as a result finally be at hand. The magnetron has actually been around since before World War II. It's a vital component in radars and …


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  1. Sebastian Brosig


    could they make it specific to <i> switched on </i> electronics? Then they could fry all the annoying git's mobiles in the cinema/concert hall!

  2. Pawel 1

    Faraday's cage

    Have they heard of it? Or in case of radio equipment, have they heard of optical encoders of the signal (so that in case of the attack, you need to replace only the relatively inexpensive antenna module)?

    As for their "Active Denial System", I'm really waiting for it to be banned under Human Rights Convention - it will blind people instantly if directed at upper body parts due to the lens of the eye not having any way of quickly dissipating the heat. That's why their demos are only on single volunteers, directed at their legs - they can quickly switch the damn thing off if the subject trips and lands with his eyes in the striking range of the beam.

    Mine's the one lined with tinfoil.

  3. David Pollard


    But are they working on the peaceful use, to stop swarms of locusts in their tracks?

  4. Anonymous Coward

    @Sebastian Brosig

    You mean, along with the projector (cinema), DMX lighting effects (concert hall) and sound systems (both)??

    Not to mention the various alarm sensors, which in failure mode could trigger an alarm and evacuation condition...

    Now, what's preferable to you? a couple of people's mobes going off, or complete lights and sounds failure accompanied by alarm bells and sprinkler activation, whilst everyone stampedes towards the exits that they cannot see as these places are designed to be completely dark in the absense of artificial light???

    Sounds like fun... let me know when you're going to do it so that I can have a good laugh!

  5. It wasnt me


    Its not going to jam a roadside bomb or a kalashnikov though is it ?

    Waste of time.

  6. Nigel 11


    A bit drastic, don't you think? Especially if you fried some unfortunate person's heart pacemaker as well.

    In the USA, auditoriums are often equipped with mobile-phone "jammers". That moniker is probably inaccurate - I suspect it's a sort of gimmicked femtocell base-station to which all phones in the auditorium will connect, and once connected, they'll receive no calls or texts from it. In the UK, such devices aren't legal. They should be permitted (perhaps subject to licensing and site surveying to make sure they don't "leak".)

    BTW you can buy a genuine jammer on the "black" market, and probably on E-bay. However, do ask yourself whether you'd want it turned on in your vicinity when you had a heart attack ... one reason they are *totally* illegal.

  7. Schultz

    New Gizmo?

    The description sounds like an old gizmo with a little tweak. Mu-metal might allow a more compact magnetron design, but it isn't new physics.

    Good PR though, shout it out!

  8. The Original Ash

    @ Sebastian Brosig

    Any sufficiently powerful source of radiation in the GSM spectra will prevent mobile phones from working. No need to fry the devices, just block the signal.

    That, or a coating of paint with metal filings will usually do the trick.

  9. Andraž 'ruskie' Levstik

    Or just use a faraday cage

    Put the entire theather in one and poof no more annoyances.

  10. Fazal Majid

    GoldenEye scenario

    Terrorists would not use it against civilians directly. The more likely usage scenario would be firing such a weapon against Wall Street to cause mass economic mayhem.

  11. Hermes (nine inch) Conran

    @ David Pollard

    Mmmm......... Fried Locust!

  12. Martin 19

    "Microwave in seconds rather than minutes"

    Not possible I'm afraid; the power of microwave ovens is limited by the power output of a domestic mains socket, after taking into account the effeciency of the magnetron.

    If this technology makes magnetrons more effecient, rather than merely having a higher power density (the article isn't clear about this) then it's possible that microwaving a curry-for-one would be faster. Even then, time needs to be allowed for the 'food' to heat evenly; hence the 'take out and stir' step in most microwave recipies.

    Assuming a theoretical 100% effecient microwave, the maximum power would be 3120W (240v x 13A). I estimate that this could cook a 2-min bag of microwaveable rice in 32 seconds (vs. 2 mins in a current 850w output oven).

  13. H 5

    More efficient not better

    thats what i understood, more power per Kg in the device.

    Still, I for one await the USB One-Mug MiniMicrowave.

  14. Pawel 1

    @Martin 19

    You forget about impulse power - microwave can charge for some time while it's connected to mains and then emit the power in short time.

  15. Anonymous Coward

    Martin 19

    Don't forget that magnetrons are usually pulsed. The input power being fed into a staging curcuit to build up the peak power available to the magnetron.

    While the average power might be around the 3KW area the peak power is usually orders of magnitude above average.

  16. Martin 19

    @Pawel 1

    Indeed sir.

    I just hope that the batteries for such a menacing device would not be manufactured by Sony- imagine the destruction caused by a huge exploding li-ion battery attached to an operating 5kw microwave!

    If that happened, could you consider your curry to be adequately 'cooked'? :)

    /flames, obviously

  17. Seeker

    Misleading Thumbnail

    What's it got to do with the film 'Scanners', which is the thumbnail pic? I was hoping to be able to fry people's brains with this, not just break their mobile phones. Oh hold on I can stop people using their sodding iPhones with this? When's a consumer version coming out?

  18. Brian 6

    @ every one saying Faraday Cage

    When your car gets zapped by lightning its body work acts as a Faraday Cage, but that doesn't stop your mobile phone working.

    @ Martin 19 "the power of microwave ovens is limited by the power output of a domestic mains socket, after taking into account the effeciency of the magnetron." If that were true then microwave ovens in the states would take twice as long to cook as ours because of there 110v system. But they don't cos your wrong.

  19. Count Ludwig

    "Microwave in seconds rather than minutes"

    MOE: I got this deep fryer on loan from the US Army. It can flash fry a buffalo in 40 seconds

    HOMER: 40 seconds? But I want it now!

  20. Scott Wichall


    I would be more interested if they had developed a magnetron that could flash chill beer

  21. John Murgatroyd

    what happened to

    The inverse square law ?

    Anyway, its not power it's volts surely.

  22. Anonymous Coward

    "And microwave ovens...

    ...will become able to pop your popcorn or heat up your frozen Hungry Hombre ranch-style jumbo meal-slab feast module in seconds rather than interminable minutes."

    Wouldn't the food have to be able to conduct heat through itself fast enough? Otherwise it'd just burn.

    And Mythbusters did a thing about Microwaves heating things up from the inside out. Apparently they don't.

    Also, does anyone else think that the new Magnetron in the linked article looks a bit half-life-ish?

  23. Ragarath
    Thumb Down

    @ @ every one saying Faraday Cage

    Erm the mobile phones work because the gap between the cage (car) is effing huge and the tiny wave lengths get through, 15.6cm i recall @ 1800mhz.

    Surely a faraday with smaller holes would work.

  24. Sir Runcible Spoon

    Faraday cages

    I actually live in a faraday cage, not a perfect one mind, but near enough.

    It does render radio waves useless, and wi-fi is a nightmare (I now have cabled the house with cat5) but mobiles work just fine. Even the (analog) walkabout phone works. Digital ones don't work very well (DECT I think it is).

    Oh, and the small power distribution point 100 yards away at one end of a long rectangular faraday cages means you can actually hear/feel the power supply when you're in the living room (end nearest the power dist. point).

    As to why I live in a faraday cage, ask the twat who decided to re-build the C17 thatched cottage with wire mesh and concrete instead of lathe and plaster....and THEN get the effing thing listed.


  25. Anonymous Coward

    RE: Sebastian Brosig

    Nice idea, but if given the option of going to a cinema where the owners intentionally microwave the audience during the film in order to intentionally break any phones that might be switched on, even if they are on silent...



    I'd know which one I'd choose.

  26. Anonymous Coward
    Anonymous Coward

    My useless opinion

    My Father was an engineer during the second world war. He worked on high power systems and Magnetrons for the military…radar jamming technology - a very loud white noise microwave generator. He didn’t talk much about it citing legal issues like The official secrecy act but did mention once that even back then they where attempting to use focused microwaves to disrupt electronics…Curious that my Mother who was in Military Intelligence received a letter from the government releasing her from the Official Secrets Act but my father never received any such release letter, He used to joke about it ….good luck on prosecuting him he passed into the night fifteen years ago..

    They almost have the ray gun. now were is my jet pack and flying car they said we would have by the turn of the century...

  27. Anonymous Coward

    Free Power

    A thin sheet of alu foil will stop this weapon dead in its tracks, better yet, use a copper coil to transfer the electrical power into some batteries that power your own personal rail gun!

    This kind of weapon would be easy to take out with a missile, it would show up 100s of miles away.

    I will stick with sharks with frickin laser beams on thier heads, thank you very much.

  28. adrianww

    @Fazal Majid's GoldenEye Scenario

    As we all know, you don't need to bathe Wall St in microwaves (or anything) for it to cause a global financial and economic crisis. Just leave the silly money-grubbing buggers alone without keeping a close eye on them for a while and they'll screw it up all by themselves...

  29. Alastair McFarlane

    @Brian 6

    Not an expert, as some people here obviously are (no sarcasm intended), but isn't that voltage, as distinct from power (which is the voltage multiplied by the current in its traditional definition)

  30. Alex Rose

    @ Brian 6

    ""the power of microwave ovens is limited by the power output of a domestic mains socket, after taking into account the effeciency of the magnetron." If that were true then microwave ovens in the states would take twice as long to cook as ours because of there 110v system. But they don't cos your wrong"

    Voltage is not a measure of power output. May I humbly suggest that you go back to your high school physics text books and re-read them to find out why it is you, sir, who are wrong.

    Also your primary school spelling primer - there, they're and their are different words and mean different things.

    If you're going to act like an acerbic twit at least get your facts right.*

    *Free lesson in different meanings of "your" and "you're" thrown in for good measure!

  31. lukewarmdog

    wall street

    Microwaving Wall Street might actually save the economy.

    It would be more likely used to blackmail big investors.

  32. Fred Flintstone Gold badge

    Ah, but think of the privacy benefits

    Put one of these outside an airport, aimed at passport control, one short blip per 5 minutes or so. No more RFID passports..

    "Sir, your passport doesn't work". "Yeah, I work with microwave equipment. Serves you right for not providing adequate shielding". "Ah, I see. This unfortunately means we will need to perform a cavity search"

    "Noooooo! Not with those big hands!!"

    You still can't win :-)

    Mine's the one with the lubricator..

  33. Toastan Buttar

    Mu-Metal not such an innovation.

    I thought KoЯn and Limp Bizkit came up with that in the 1990s.

  34. Hermes (nine inch) Conran

    @ Brian 6

    I'm afraid Martin 19 is correct, The power of Brit and Merkin domestic sockets are limited by the law that say power = Volts * Amps. Merkins have a lower voltage but run more amps to acheve the same power.



    cos you're wrong!

  35. Alastair McFarlane

    @Alex Rose

    Yeah that's what I was going for. Please don't point out my lack of question mark was a mistake, honest!

  36. Dave 32
    Thumb Up

    Magnetrons since 1920

    Magnetrons have been around a lot longer than the WWII era. They were initially developed by Albert Hull, at GE, in the 1920s, as an outgrowth of his work in using magnetic fields to control electron tubes as a way of getting around DeForest's patents on the triode.


  37. Simon B

    How long before the enemy/criminals have the plans?!

    And in todays news, the plans for this device have accidently been found unencrypted on a lost USB stick / laptop from ebay / insert another here and the enemy have now made their own.

  38. Anonymous Coward
    Paris Hilton


    the mil directed energy weapons ongoing development reached megawatts very quickly , are currently at gigawatt outputs and are trending to terawatt power levels. There was some debate that inverse square law doesn't quite apply when you're ionising the medium you're propagating thru' but I don't want to get into that now! perfect faraday cages will attenuate/reflect a lot of the RF energey but do you have ANY gaps or ANY wires in/out? powerlines/phones/water/gas pipes?? any antennas on the roof?? TV/radio/cable/sat? well, some of these RF weapons perform an RF 'survey' - > hundred metres stand-off RF network analysis S11/S21 stuff, then couple the terawatt to the most penetrative frequencies. Quote "if the bunker has a single wire to the surface I can scope that then take him out" (backdoor coupling in the jargon, hence icon!)

  39. Random Coolzip

    @Brian 6

    "When your car gets zapped by lightning its body work acts as a Faraday Cage"

    And apparently its tires have stopped working as insulators... (or it's sitting on cinder blocks next to your trailer).

  40. Blake St. Claire


    > Merkins have a lower voltage

    News to me.

    We have 240v to the house. The transformer up on the pole has a tap. We run three wires to the house, the third wire (neutral/ground) is attached to the center tap on the transformer. Thus we get 240 for water heaters, stoves, ovens, and to charge our electric cars and rayguns; and 120v for everything else.

    Wish you guys would get this figured out. It's not too much different than what you have: 408v 3-phase up on the poles. Your transformer on the pole has three taps, you take any two to give you 240v.

  41. Bilby

    @ Simon B Posted Thursday 17th September 2009 15:54 GMT

    "How long before the enemy/criminals have the plans?"

    If the plan is to use expendable pilotless drones to deliver this weapon, not long at all.

    IIRC during WWII the use of microwave radar sets in aircraft that flew over enemy occupied territory was forbidden for a long, long time, as the magnetrons were virtually indestructible, and any aircraft that failed to make it home was likely to gift the technology to the Germans, even if not much else on the plane survived.

    As the centimetric radar was being put to excellent effect in the battle against the U-boats in the North Atlantic, the Royal Navy (and RAF Costal Command) were dead set against letting Bomber Command fit them in their Lancasters, as the Germans would be able to work out why their subs were suddenly vulnerable to aircraft when charging their batteries by snorkel at night (the snorkel and periscope were far too small to be picked up by conventional RADAR, and were practically impossible to see by Mark I Eyeball even in good daylight conditions).

    Once the bombers were given the sets, which proved an invaluable navigation and bomb-aiming aid, they were codenamed H2S, because "it stinks that we were not allowed them sooner".

    I don't know if the design is much more 'fragile' when made from Mu-metal than it was with the old copper magnetrons, but if they are not, I doubt that they are going to be totally destroyed in a crash, even if a fairly large demolition charge is provided for the purpose.

  42. Anonymous Coward
    Anonymous Coward

    There are some problems with your comment: * The title is too long.

    "Terrorists would not use it against civilians directly. The more likely usage scenario would be firing such a weapon against Wall Street to cause mass economic mayhem."

    The banks seem to be doing that just fine on there own.....

  43. Il Midga di Macaroni
    Thumb Up

    Biggles adventures come true!

    Every second Biggles adventure at least mentions a frightening new device which can affect a plane's magnetic compass and then kill its ignition to bring it down. 60 years later, it *might* be happening. Why don't we all just go and live in the world of fiction? Things are easier to invent there.

  44. David Haig
    Thumb Up

    Sounds like ......

    .... a project for the BOFH and the PFY

  45. Matt Bucknall


    It is a well known fact that subjecting locusts to microwaves causes them to grow to 50x their normal size and develop a taste for human flesh.

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