back to article Geiger counters are so last summer. Lasers can detect radioactive material too, y'know

Lasers could be used to detect radioactive material secretly transported to and from ports one day, according to a group of physicists from the University of Maryland in the US. The boffins describe a proof-of-concept method that can sniff out the particles emitted from radioactive decay using a technique known as an “electron …

  1. the Jim bloke Silver badge
    Mushroom

    With a big enough laser

    You dont need a nuke at all

    1. Korev Silver badge
      Mushroom

      Re: With a big enough laser

      Oh yes you do... You need to mutate those sea bass somehow

    2. Anonymous Coward
      Anonymous Coward

      Re: With a big enough laser

      Dead Russians are a good indication of radioactive material too allegedly. Anon due to acute Polonium allergy.

  2. Neil Barnes Silver badge
    Boffin

    Not a nuclear scientist here...

    but isn't the significant thing about an alpha decaying radioactive source the fact that alpha particles don't go all that far in air, and can be stopped in general by even packaging, let alone shielding? Unless of course it's such a strong emitter that it's glowing in the dark and already looking distinctly unhealthy to all and sundry?

    The point being that someone smuggling radioactives is hardly likely to stick them conveniently on the outside of the box.

    Or did I misunderstand something fundamental in either the piece, or in 40-year-old A-level physics?

    1. Anonymous Coward
      Anonymous Coward

      Re: Not a nuclear scientist here...

      My primary field is nuclear engineering and you aren't the only one a bit puzzled by this. Theoretically, that alpha particle should be moving at a very good clip so, perhaps, there is sufficient penetration outside any containment to be significant. I really need better numbers to say one way or the other. As to the assertion of radically improving the detection range, that's another wait and see. If you check the article (not paywalled, yay!) they use numerical simulations to make their case. I've enough engineering to know: "In theory, theory and practice are the same. In practice, they ain't."

      By the way, this principle should also work for beta and fast neutron emitters which is promising right there. Now how the heck you'll distinguish natural sources (ceramics, bricks,...) from smuggled material is left as an exercise for the student.

      1. Terje

        Re: Not a nuclear scientist here...

        I have the feeling that this would be very easy to get around even using low tech methods. Seeing as we are basically detecting electrons then simply pack your radioactive material in some material that will readily grab that electron and you can no longer detect it.

        1. Rich 11 Silver badge

          Re: Not a nuclear scientist here...

          simply pack your radioactive material in some material that will readily grab that electron

          Or just shield your radioactive material as normal, so that the alpha particle doesn't get as far as air in the first place.

          This does seem more like a way of scanning for leaks rather than for looking for contraband materials, especially given the potential distance component. Not to say that contraband couldn't leak, but you'd expect considerable precautions to be taken by the smuggler anyway.

      2. Mystic Megabyte Silver badge
        Happy

        Re: Not a nuclear scientist here...@Jack

        Hi Jack! My father used to say that in theory ½" x ½" was ¼" but in practice it's an inch!

      3. Bilious
        Mushroom

        Re: Not a nuclear scientist here...

        Cobalt 60, the example of the story, is best known for emitting gamma radiation.

        https://en.wikipedia.org/wiki/Cobalt-60

        So maybe the method is not about alpha radiation at all?

    2. Thoguht Silver badge

      Re: Not a nuclear scientist here...

      Sounds to me like they are assuming the weakly-ionised oxygen atoms will leak outside of container that holds the radioactive material. In which case all you need to do is make sure the container is airtight.

    3. Cuddles Silver badge

      Re: Not a nuclear scientist here...

      "but isn't the significant thing about an alpha decaying radioactive source the fact that alpha particles don't go all that far in air, and can be stopped in general by even packaging, let alone shielding?"

      On the one hand, yes. But on the other hand, that applies to any method you might try to use to detect stuff. So this method won't be any worse in that respect, but may have benefits over other detection methods in other ways.

      Exactly why they think anyone is smuggling large quantities of radioactive materials through American ports is a more difficult question to answer.

      1. CN Hill

        Re: Not a nuclear scientist here...

        "Exactly why they think anyone is smuggling large quantities of radioactive materials through American ports is a more difficult question to answer."

        Nukes in shipping containers.

        1. Anonymous Coward Silver badge
          Flame

          Re: Not a nuclear scientist here...

          "Exactly why they think anyone is smuggling large quantities of radioactive materials through American ports is a more difficult question to answer."

          Haven't you seen the documentary about that? The Sum of All Fears. https://m.imdb.com/title/tt0164184/

        2. Anonymous Coward
          Anonymous Coward

          Re: Not a nuclear scientist here...

          It's been said that the US worries about the Iranians developing IRBMs but the real risk is the crude, non-air-deliverable weapon on its way through Mexico in the back of a truck.

      2. Ian Michael Gumby Silver badge
        Boffin

        Re: Not a nuclear scientist here...

        Uhm... this may be a silly question... but what makes you think that they are only monitoring US Ports?

        Team America! World Police. (Yes the version w the gratuitous puppet sex!)

        (Sorry its Monday.)

        But seriously, the proliferation of nukes should scare the shit out of most. Even if you live in the UK and someone did an air burst above San Francisco, (think high EMP low casualties) ... You'd still be royally fscked.

        Or NYC.

        And vice-vesa. (Living in the US and London taken out w EMP burst.) Are your civilian data centers protected against EMP bursts? I doubt it.

        1. Korev Silver badge
          Joke

          Re: Not a nuclear scientist here...

          You mean Brits wouldn't be able to get to Facebook any more? :-o

        2. Jimmy2Cows Silver badge

          Re: Not a nuclear scientist here...

          Genuine question... you really think an EMP from an airburst nuke over SF would have enough energy after travelling 5351 miles to take out London?

          Stuggling to believe that given inverse-square scaling of enery over distance, and that there's a significant amount of planet between SF and London.

          Unless the airburst was pretty much in orbit. And even then it's gotta be a high orbit to see London from above SF.

    4. Daedalus Silver badge

      Re: Not a nuclear scientist here...

      Yes, an alpha particle emitted by a typical radioactive substance literally cannot fight its way out of a wet paper bag. As proven in Nuffield Physics (ah, those were the days) when our very much not H&S compliant radium sample had its three types of radiation blocked by, successively, blotting paper (another retro ref), aluminium and an inch or two of lead.

      1. M. Poolman

        Re: Not a nuclear scientist here... (Nuffield Physics)

        Happy memories. In those bygone days my physics teacher used a fag paper to demonstrate how easily alpha particles could be stopped.

    5. Apub-tt

      Re: Not a nuclear scientist here...

      "We note that all radioactive sources of interest, whether α, β, or γ emitters, result in free-electron generation from the ionization of ambient air."

      Alpha is used as a proof-of-concept. Likely because of containment/safety and convenience/what is available. Optical labs aren't the most spacious of places and things like this are typically built on 3 x 1 m optical tables that need access from all sides.

      The advertising point is that this device can be operated in a stand-off manner up to 100 m (with higher pulse energy keep in mind). Seeing how the optics alone will cost more than an industrial Geiger, what's stopping a technician strapping a Geiger meter to a remote control car or a drone and doing the exact same thing?

    6. a_yank_lurker Silver badge

      Re: Not a nuclear scientist here...

      I understand the idea is to look for an effect of alpha emissions that are not affected by thin shielding that would stop an alpha particle. Still I wonder how effective this would at any distance beyond standing practically next to the source.

    7. I3N
      Pint

      Re: Not a nuclear scientist here...

      WIRED strikes again!!!

      I'll keep my geiger counter collection - Victoreens, Lionels and Antons, thank you very much ...

  3. Manolo
    Black Helicopters

    Wait, what?

    "An infrared laser can ionise those seed electrons "

    How can you ionise an electron?

    An ion is a charged atom or molecule. An electron is already charged and you can't increase its charge.

    1. A Non e-mouse Silver badge

      Re: Wait, what?

      If I underrstand this correctly...

      The seed electron weakly attaches itself to an oxygen molecule. This makes this molecule negatively charged as it now has an excess electron. As the electron is only weakly attached, the laser can easily liberate this electron.

      So perhaps the author could have said "[...] laser can liberate those seed electrons"

      1. Anonymous Coward
        Anonymous Coward

        Re: Wait, what?

        "So perhaps the author could have said "[...] laser can liberate those seed electrons""

        LGBT+e-

        Now nicely neutral.

    2. HieronymusBloggs

      Re: Wait, what?

      "An electron is already charged and you can't increase its charge."

      You're just being negative.

      1. Manolo
        Joke

        Re: Wait, what?

        Two sodium atoms are walking along the street.

        * Ohoh, I'm losing an electron!

        - Are you sure?

        * Yes, I'm positive.

  4. Duncan Macdonald Silver badge

    False Alarms

    Overly sensitive radioactivity detectors make nuisance false alarms easy. Uranium is not difficult to obtain in small quantities (over 2000 uranium glass objects are on sale on eBay for example). A few milligrams of a uranium compound on the outside of a container will give as much of a signal as a large quantity of radioactive material shielded inside the container.

    1. Ian Michael Gumby Silver badge
      Boffin

      Re: False Alarms

      There's more to this than just the detection.

      You could use it to stop a truck for further inspection, or for a port to pull a container.

      But there's more data than just coming from the sensor which you use before creating panic.

    2. Alan Brown Silver badge

      Re: False Alarms

      "Overly sensitive radioactivity detectors make nuisance false alarms easy"

      Yup.

      Truckloads of bananas are notorious for setting them off. (Yes, really)

      And FWIW: Nuclear _WEAPONS_ use radioactives of very _LOW_ radioactivity - barely higher than background levels until they hit critical mass.

      Contaminants like Colbalt 60 (or isotopes of uranium other than U235/U238, or non-bomb isotopes of Plutonium) are _too_ radioactive and cause things to go off prematurely, resulting in "fizzles" rather than "booms"

  5. Smooth Newt
    Meh

    Unshielded sources

    A good and potentially useful piece of research, but I am not sure how this might be useful in detecting radioactive material secretly transported to and from ports one day, as suggested. The most dangerous materials are alpha emitters (plutonium, polonium, radium etc) and would be contained in packaging that will stop all the alpha particles.

    Plus, they are so toxic that only very small amounts are required for nefarious purposes - you aren't going to get a skip full of polonium coming through customs - perhaps a tiny 0.1 millilitre vial of some solution if you are very lucky, from which no radiation will escape.

  6. Pascal Monett Silver badge

    "It begins with shining an infrared laser beam near a radioactive source"

    Um, sorry, but if your method of finding a radioactive source starts with targeting it then your method doesn't work if you don't know where it is.

    Geiger counters work because you just walk around and detect radioactivity. The laser method would mean you have to scan every individual package or crate, and that would only work if every incoming/outgoing crate passes through the same point. I don't think that's going to happen at a large port, or any port for that matter.

    Obviously, I know nothing about ports (for ships, that is - for firewalls I know more).

    1. Tom 7 Silver badge

      Re: "It begins with shining an infrared laser beam near a radioactive source"

      If this method works then there is a chance for some improvement over a Geiger counter. I'm imagining here the origin of the laser beam does not need to be near the radiation source, whereas a Geiger counter does. If this is the case then scanning could be done from a distance and presumably at speed.

    2. Jon 37

      Re: "It begins with shining an infrared laser beam near a radioactive source"

      I think the idea is that instead of walking around a container with a geiger counter, or rigging up some way for a robotic arm / drone to move the geiger counter around, you instead have two lasers at opposite corners of the container. They quickly scan the whole container. Or you have two lasers each side of the gate that the lorries drive through, so you scan containers as they leave the port. Or you just have a laser on a van and drive around the port pointing it at things, you don't have to worry about climbing up close to the containers.

      Alternatively, you could imagine that with enough development they may be able to make a hand-held device a bit like a FLIR infra-red scanner, which shows the operator a picture of the amount of radioacivity. They stand on the docks and point it at the containers from a distance, and look for radioactive hotspots to investigate further. This could also be useful to people working in radioactive cleanup (e.g. Chernobyl, Fukushima, Sellafield, reactors being decommissioned ...).

  7. Headley_Grange Silver badge

    Bananas

    UK ports of entry already have radiation detectors; the system is called Cyclamen. If you bring your own weight in bananas back through the airport then you'll set them off. Probably.

    1. Omgwtfbbqtime Silver badge

      Re: Bananas

      "Sources as weak as 1 microgram of Cobalt-60"

      We need to know what that is in bananas.

      1. Yet Another Anonymous coward Silver badge

        Re: Bananas

        Cobalt-40 = 45 TBq

        Banana = 15 Bq

        So 3 million million bananas

        1. FrogsAndChips Bronze badge

          Re: Bananas

          Only true if your typical banana weighs^W has a mass of 1 gram.

          1. Yet Another Anonymous coward Silver badge

            Re: Bananas

            Sorry was on phone, Cobalt should have been activity/g banana is per fruit

      2. FrogsAndChips Bronze badge
      3. Doctor Syntax Silver badge

        Re: Bananas

        "We need to know what that is in bananas."

        K40

      4. Paul Hovnanian Silver badge

        Re: Bananas

        Yes. We have N bananas.

  8. AdamT

    Power?

    As soon as you start talking about your laser ionising the air (presumably that needs a decent power density) and then detecting the backscatter i.e. you either need incredibly sensitive detectors or need to increase the power some more, I'm starting to wonder if your laser is now a rather serious hazard to all eyes and even physical objects in the vicinity...

    1. Anonymous Coward
      Anonymous Coward

      Re: Power?

      I get this vision of cars driving off a ferry, all with a longitudinal stripe scorched into their paint from the scanning.

      "Yeah, my door fell off, been abroad too often"

      :)

      1. AdamT

        Re: Power?

        Also, there is a hint that they are proposing that this could be mildly covert (e.g. the "length of a football field" comment) which could be slightly compromised by the need to hand out safety goggles first...

        "Why do I need these?"

        "Oh, no particular reason, just a precaution"

        "Oh, right, sure..."

        "Seriously, don't take them off though."

        1. Headley_Grange Silver badge

          Always wear goggles while smuggling.

          The paper talks about powers of 1.3E12 W/cm^2. The focal spot is v. small, as are the pulse widths, but they don't mention the duty cycle. My money is on the goggles melting.

          1. Yet Another Anonymous coward Silver badge

            Re: Always wear goggles while smuggling.

            Yes but you will be safe from all that radioactivity

    2. FrogsAndChips Bronze badge

      Re: Power?

      The article mentions an infrared laser. But I'm not an optician, so I've no idea of the kind of damage a powerful IR laser could actually do to my retina, and I don't particulary want to find out.

      1. Ashentaine
        Flame

        Re: Power?

        I'm pretty sure a laser like that would demolish your eyes before you even had time to blink. The cheap green laser pointers that are sold online can cause permanent damage with only a short direct exposure, since they often don't have an IR filtering lens in them to keep the cost down.

        Oh, and most types of safety glasses designed for use with lasers don't filter out IR either (as again, good quality lasers have a built in lens to filter that), so don't be surprised if ze goggles, they do nothing.

        1. Alan Brown Silver badge

          Re: Power?

          "Oh, and most types of safety glasses designed for use with lasers don't filter out IR either"

          Unless you buy ones specifically sold to knock out IR - which is a good idea given the lack of filters in most things containing doubler crystals.

          1. Ashentaine

            Re: Power?

            True, though such glasses tend to be crazy expensive. But if you're in a situation where you're around lasers frequently, then it goes without saying that it's worth the cost.

  9. Doctor Syntax Silver badge

    Alpha particles are helium nuclei so I'd have thought they're going to be pretty good at mopping up any stray electrons.

    1. Tom 7 Silver badge

      Not when travelling at speed. They tend to stop rather quickly but that's because they cause a lot of damage to everything they pass near.

      Its a bit like driving an F1 car into a crowd - the bodies fly quite high!

      1. Yet Another Anonymous coward Silver badge

        No they are, for radioactive particles, going quite slowly.

        A beta emmitter (a single fast elecron) is like driving an F1 car into the crowd, you get a long way but only hit a few people in the path.

        An alpha particle is like driving an 8000ton bulldozer into the crowd

        1. Doctor Syntax Silver badge

          "An alpha particle is like driving an 8000ton bulldozer into the crowd"

          Or a bus. It might plough on but once it stops it can pick up a couple of passengers.

  10. Arthur the cat Silver badge

    1 microgram of Cobalt-60

    Most of the article talks about alpha particles, but then mentions Co60, which emits beta particles and gamma rays. The latter are a lot more likely to cause ionization.

  11. Nick Kew Silver badge

    Static?

    The article describes ionising molecules in the air. But doesn't a bit of static do that too?

    Could it possibly be that the boffins have done an experiment in a controlled environment, but that in the real world their effect will be dwarfed by what you're wearing, and the carpet?

    And what happens in a thunderstorm, when everything is ionised?

    1. Anonymous Coward
      Anonymous Coward

      Re: Static?

      And what about back-scatter from all those dust particles in the air...

  12. tojb

    Might have saved Litvinenko

    As I remember, the Russian assassins who did for Litvinenko didn't make any attempt to transport their polonium in an airtight lead box, so it would have showed up on one of these scanners. It would also have showed up on a Geiger counter, as the isotope they used is more than just a bit radioactive, but I guess maybe they aren't installed in British airports right now anyway.

    1. Yet Another Anonymous coward Silver badge

      Re: Might have saved Litvinenko

      Most airports don't check for smuggling weapons off flights.

      Odd that it wasn't detected in Moscow

      1. Headley_Grange Silver badge

        Re: Might have saved Litvinenko

        @YAAC - "Most airports don't check for smuggling weapons off flights."

        They do today. Search for "Project Cyclamen". I think that Cyclamen airport installs started in 2005/6, just a bit too late for Litvinenko.

        You can spot them in some airports - in others they are built into the infrastructure and can't be seen. Look for beige plastic pillars or frames as you go through the red/green/blue channels when you exit the baggage claim area. Don't look too hard, though, otherwise it could be latex-glove time.

    2. Anonymous Coward
      Anonymous Coward

      Re: Might have saved Litvinenko

      Polonium is an alpha emitter, you can transport it in a small glass bottle and absolutely nothing will leak out. So long as the glass doesn't contain anything that might emit other particles if hit by an alpha.

      In fact, following Skripal, I suspect they had it in a perfume spray as was used there. It would look like any other duty free and, as I say, no external radiation. It was just that the assassins were amazingly careless how they used the stuff.

      But, as has been pointed out elsewhere, secret service officers don't do the dirty work. They prefer to use the sort of deniable types that left the Hereford lot under a bit of a cloud due to over enthusiasm. Not people with physics degrees.

      Incidentally, the trigger of the first plutonium bomb was a mixture of beryllium and polonium with, IIRC, the polonium gold plated to stop the alphas. When the shell was imploded, the trigger ("gadget") was compressed and the alphas from the polonium caused the beryllium to emit neutrons, thus causing the very rapid criticality rise needed to produce a bang rather than a whimper. But the half life of polonium is short, meaning you had a bomb which needed to be finished shortly before it was used.

  13. Stevie Silver badge

    Bah!

    But this miracle laser thing could, in theory, scan foreign airliners as they approach Stanstead, agilely dodging the usual squadrons of drones, to see if anyone is smuggling radioactives.

    A quick sweep of the mighty laser across the airframe as it makes its approach and ... haaaang on. I think I see a problem.

    1. DropBear Silver badge
      Boffin

      Re: Bah!

      No you don't. Not anymore, anyway...

  14. Anonymous Coward
    Anonymous Coward

    So radation smells like ionazation

    Screw the laser, I'm getting a dog for detection. Naming him Rad.

    1. Alan Brown Silver badge

      Re: So radation smells like ionazation

      "I'm getting a dog for detection"

      Your dog is going to need a seeing eye dog.

  15. drewsup

    oh Great!

    Now I'm blind And radioactive!!

  16. Anonymous Coward
    Anonymous Coward

    Reinventing the wheel

    These lovely people - proper British boffins - have been around since 2003 (possibly earlier) and their ultra-sensitive detection systems enable the DoHS to detect and identify radioactive materials and discriminate between the radiation signatures of bananas and strategic nuclear materials.

    www.symetrica.com

  17. Richard 30
    Holmes

    Invited here first!

    These lovely people - proper British boffins - have been around since 2003 (possibly earlier) and their ultra-sensitive detection systems enable the DoHS to detect and identify radioactive materials and discriminate between the radiation signatures of bananas and strategic nuclear materials.

    www.symetrica.com

    1. IvyKing

      Re: Invited here first!

      With the exception of the neutron detector, symetrica's technology is nothing new, though refined with respect to previous implementations.

      There are a couple of potential advantages to the IR laser based detection. The first is a much larger detector volume, since sensitivity is related to how many of the particles or photons interact with the detector - that's why neutrino detectors are HUGE. The flip side is that the detector can affectively b placed close to the source, getting around the inverse square law. The second is getting much quicker localization of the source.

      One item not discussed in the article was spectral response, identifying a specific radionuclide may require energy resolution of better than 1%, and the method of operation suggests a very broad peak for a given energy (e.g. Tc99m at 140keV).

  18. LateAgain
    Facepalm

    Surely a "lead" detector would be more useful

    Assuming, of course, that no one is stupid enough to use gloves and brown paper wrapping when shipping radioactive material.

    1. Headley_Grange Silver badge

      Re: Surely a "lead" detector would be more useful

      @LateAgain - have a look at Muon Tomography.

  19. Anonymous Coward
    Anonymous Coward

    meanwhile the most significant radiation hazard seldom gets noted: Radon gas is estimated to cause 20,000 cases of lung cancer in the US annually, second only to smoking.

    a person living in building with average annual Radon concentration of 60 Bq/m3, would take annual effective dose of 1 mSv (60 x 0.017 = 1.02).

    Here is a map of the United States with radon risk by county - with my own personal suggestion that odds are one need please note that within any given county there can be areas much higher or lower than the average for the county.

    https://www.epa.gov/sites/production/files/2015-07/documents/zonemapcolor.pdf

    Radon Data

    Zone 1: Counties with predicted average indoor radon screening levels greater than 4 pCi/L

    Zone 2: Counties with predicted average indoor radon screening levels from 2 to 4 pCi/L

    Zone 3: Counties with predicted average indoor radon screening levels less than 2 pCi/L

    1. Alan Brown Silver badge

      "Radon gas is estimated to cause 20,000 cases of lung cancer in the US annually, second only to smoking."

      And on THAT note: https://www.youtube.com/watch?v=TRL7o2kPqw0

      The highest radiation doses may surprise you (but shouldn't)

  20. David 164

    Can it detect the radiation inside a lead box? I mean if I was a nuclear terrorist planning on smuggling a nuclear bomb into the US I personally wouldn't skimp a lead casing for the device. But hey that just me.

    1. Headley_Grange Silver badge

      The laser one couldn't detect a source inside a lead box unless they had contaminated to the outside of the box when packing it. Muon tomography might be able to depending on what the source was and how much of it there was.

      To get a source inside a lead box into the US would require the cooperation of the port of departure cos it would set off the baggage scanners on the way out.

    2. Alan Brown Silver badge

      "Can it detect the radiation inside a lead box?"

      Lead is transparent to certain types of radiation emissions. That's why it's used as coolant in certain types of nuclear reactors:

      https://www.gen-4.org/gif/jcms/c_42149/lead-cooled-fast-reactor-lfr

  21. M7S
    Mushroom

    To paraphrase slightly

    https://m.youtube.com/watch?v=NiMPJEd6OY4

  22. atropine blackout

    With current technology (and nothing dramatic on the horizon as far as I know), the powerful mid-IR laser - say in the 3..5 um region - needed for a longer usable range is a fairly non-trivial proposition.

    An interesting paper but, as other folks have noted, there may well be an awkward gap between the model and reality.

  23. sitta_europea Bronze badge

    Er, actually, I _am_ a nuclear scientist.

    On sensitivity, the calim is that a microgramme of cobalt 60 can be detected.

    Firstly, cobalt 60 is a beta emitter, not an alpha emitter, so I fail to understand why this follows an explanation about alpha particles.

    Secondly, one microgram of cobalt 60 (half life a tad over 5 years) is about a millicurie, which gives more than 40 million disintegrations per second, and that's not what anybody sane would call a tiny amount of radioactive material. For comparison, it's about ten thousand times the typical human body load of potassium 40 (something like 125 grammes, half life a bit more than a billion years, so very roughly 4000 disintegrations per second).

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