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Science Technology

Government Lab Uses Smartphones To Measure Gamma Ray Exposure 105

Posted by samzenpus from the hulk-phone-is-strongest-there-is dept.
KentuckyFC writes "Back in 2008, Slashdot reported that researchers were developing ways of turning cellphones into radiation detectors. Since then a few apps have even appeared that claim to do this. However, convincing evidence that they work as advertised is hard to come by. Now government researchers at Idaho National Labs have created their own app that uses an ordinary smartphone as a gamma ray detector, put it through its paces in the lab and published the results. The pixels in smartphone cameras can detect gamma rays in the same way as they pick up visible light. So when the lens is covered, the image should reveal evidence of gamma ray exposure once other noise has been removed, such as that from heat and current leakage. These guys have tested several types of Android smartphone with a variety of gamma ray sources at various different doses. The researchers say the phones give a reasonable measure of radiation dose, can detect the direction of source (by comparing the measurements from the front and back cameras) and can even measure the energy of the gamma rays by measuring the length of the tracks that appear in the image. While the results do not match the quality of bespoke detectors, that may not matter since in many circumstances cellphones are likely to be the only sensors that are available. That could be useful for emergency services, air travelers wanting to monitor their extra radiation dose on routes over the arctic and people who live in areas with a higher than average background radiation level."
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Government Lab Uses Smartphones To Measure Gamma Ray Exposure More

Government Lab Uses Smartphones To Measure Gamma Ray Exposure

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  • My iPhone is getting Angry! (Score:5, Funny)

    by jellomizer ( 103300 ) on Monday January 13, 2014 @12:57PM (#45940629)

    You don't want my iPhone getting Angry!

    • So can the phone detect the radiation it is generating and solve that endless debate as to whether cellphones are causing brain tumors?

      • I don't think there was ever any question that phones generate radiation, that is what the antennas are for. But this is for gamma rays, if your phone is generating any of them then something is horribly wrong.

        • if your phone is generating any [gamma rays] then something is horribly wrong.

          Substitute "more [gamma rays] than your head" for "any [gamma rays]"? Your phone will be generating gamma rays ; so will your head. And, let's hit below the belt, so do your balls. (Ovaries if appropriate ; or both if you've got more options than most.)

      • that endless debate as to whether cellphones are causing brain tumors?

        You mean the debate that ended in the early 1990s (for mobile phones), in the 1970s (for power lines) and the 1930s (for radium compounds)?

        Who resuscitated this old corpse again?

    • "Don't make me android. You wouldn't like me when I'm android."

    • Is that a Mystery Men joke?

    • Re: (Score:1)

      by Anonymous Coward

      my iPhone

      They said *Smart*-Phones

  • Two words (Score:3)

    by cold fjord ( 826450 ) on Monday January 13, 2014 @12:57PM (#45940633)

    HULK SMASH!!

    Does sound like a neat idea. I'm hoping there won't be much call for it outside of labs though. I'm not a big fan of excessive radiation.

    • Read again. It doesn't generate radiation. It's not a nuclear power plant.

      Though if someone writes an app to turn the phone into a safe nuclear power plant it might be popular.

      • It's not a nuclear power plant .... Read again. It doesn't generate radiation. It's not a nuclear power plant.

        Though if someone writes an app to turn the phone into a safe nuclear power plant it might be popular.

        The danger isn't what they propose to put in your pocket, the danger is what they are trying to detect! (Ignore the radiation leak, the cell phone poses no threat.)

        A cell phone into a "safe nuclear power plant"? *_*

    • You don't like the sun?

      • From what I hear gamma radiation come from more sources than just the sun, sometimes in dangerous dose rates.

        But I'm intrigued, are you suggesting that solar radiation never poses a risk under any circumstances?

        • But I'm intrigued, are you suggesting that solar radiation never poses a risk under any circumstances?

          Obvious trollbait is obvious.

        • Holy shit that's bad reading on your part

          GGP - "I'm not a big fan of excessive radiation"
          GP - "You don't like the sun?"
          You - "are you suggesting that solar radiation never poses a risk under any circumstances?"
          Me - WTF are you reading?

          • Smoking stuff in many instances is now legal. So lots of people are smoking stuff, including while reading /.

          • You're either asking the wrong person, or not following the conversation.

            • No, his summary is accurate. Maybe you didn't read what you wrote?

            • Like many other topics, cold fjord, you're on the wrong side.

              • Which part, exactly? The part where I think it's a neat idea? The part where I hope it isn't needed much outside the lab - since it is intended to measure excess radiation, including in emergency situations? Or the part where I state I'm not a fan of excess radiation?

                Are you suggesting I should be a fan of excess radiation and radiation emergencies? I'm curious.

                • Apparently, you have to have it spelled out for you.

                  First guy says I'm not a big fan of excessive radiation.
                  Second guy says you don't like the sun?
                  You say Are you saying the sun doesn't have excessive radiation?
                  Second guy is like, no I was saying that the sun does have excessive radiation
                  I'm like you're an idiot.

                  • Thank you for spelling that out. My post was the first one in that thread that you attribute to, "First guy." The second guy was confused in his reply since the question is detection of excessive radiation, not the sun. You don't really summarize my next point correctly since the point is that sun's radiation can pose a hazard, not that it is excessive. The post that I replied to was basically off topic. In summary, you've got it wrong. The one you should be complaining to and about is the other guy.

  • Digital camera elements (Score:4, Interesting)

    by i kan reed ( 749298 ) on Monday January 13, 2014 @12:59PM (#45940661) Homepage Journal

    I've always wondered why we can't do simple infrared or ultraviolet examinations of things with our smart phones.

    I have a sneaky suspicion it's because not all clothing is opaque in those spectra, but I like neat science toys, and wish my phone was a little more tricorderish.

    • The sensing elements used in the cameras are designed for their purpose. They will generally have a limited range of sensitivity in terms of the wavelengths they detect. Different materials and sensor element designs may be needed depending on the wavelength, required sensitivity, and other aspects of the intended use and environment. Something that works well for infrared may not work well for UV detection and measurement. Doing it all uncooled adds other challenges.

      • Re:Digital camera elements (Score:5, Informative)

        by Immerman ( 2627577 ) on Monday January 13, 2014 @01:23PM (#45940915)

        Actually most digital cameras are far more sensitive to infrared than to visible light - they actually come equipped standard with infrared blocking filters so that the visible spectrum isn't totally drowned out, and they *still* can usually see the wimpy blinking light on your IR remote. I think they're usually less sensitive to UV though.

        • Re: (Score:1)

          by Anonymous Coward
          The poster you replied to would be correct if you take the whole camera into consideration, instead of just the sensing element. As designed, which means including the IR filter, it will not do a good job of picking up IR (and UV typically sucks on cheap optics). That IR filter is not there because of being able to see through people's clothing, especially since I haven't seen such problems when removing such filters to make cheap IR laser diagnostics, but because your visible images will suck without in

        • Re: (Score:2)

          by ceoyoyo ( 59147 )

          Not far more sensitive. They are sensitive to IR, and do come with a filter to block it out, but they're not sensitive to very much of the IR spectrum, and not particularly sensitive to even that part, so taking IR photos is an exercise in low light photography.

        • Re:Digital camera elements (Score:4, Insightful)

          by hubie ( 108345 ) on Monday January 13, 2014 @03:08PM (#45942565)

          Digital cameras are very insensitive to the IR. Silicon, which is what all commercial camera sensors are made of, loses its sensitivity around 1000 nm, so photons with a longer wavelength than that generally pass through undetected (they are most sensitive around 600-ish nm, which is something like orange light). On the other hand, if you look at the spectrum of light coming from the Sun, you get the most photons around that same 600 nm wavelength (how's that for coincidence?), but you also still have a whole lot of photons flying around with wavelengths of 1000 nm and less. Camera makers put IR-blocking filters on because the optics for the cameras are optimized for visible wavelengths, so IR wavelengths will not come to a nice focus. These IR wavelengths add image blur. Some people want to pop their IR filters off because it will make their camera more sensitive, which technically is true, but you'll make your pictures look blurry unless you do something else (i.e., filters) to restrict the wavelengths of light through your optics.

          You also have to be careful when you talk about the IR that these cameras can detect. What you're really talking about is very deep red, or the first parts of the NIR (near infrared) region. Most people, when they hear IR, think heat signatures, but that is not what you're dealing with here. The thermal IR is much longer wavelengths, and you'll never see that with a silicon-based camera. In fact, pure silicon is very useful as a window material for IR sensors because it is very transparent to photons at those wavelengths.

    • Re: (Score:1)

      by Anonymous Coward
      And I wish my door opened automatically with a 'swoosh'ing sound. But neither one of these things is going to get either of us laid.

    • Re:Digital camera elements (Score:4, Interesting)

      by Lehk228 ( 705449 ) on Monday January 13, 2014 @01:17PM (#45940845) Journal
      infrared and ultraviolet are intentionally excluded from cameras with filters so that the image recorded looks like it should, I suppose filters could be applied on a per pixel basis in order to make a 5 or more element R,G,B,IR,UV sensor, but the cost would be .... considerable

      • Would it really be that much more than an RGB filter?

        • A filter removes a portion of something. You filter out things. Phone cameras don't use an RGB filter. That would defeat the point of having a camera. If we assume it takes 2 discrete filters to remove IR and UV, RGB filters would add another 3 (assuming we kept the same constraints, one per narrowly defined band, which we need not do in reality). Would it cost more to manufacture a sensor which detects all of them? No. They generally do that just fine anyway. Hence the filters. Would it cost more to have

          • A filter removes a portion of something. You filter out things. Phone cameras don't use an RGB filter.

            Actually, they do. The standard single-chip image color image sensor uses what is called a Bayer filter array [wikipedia.org] of red, green, and blue color filters in a regular pattern, one filter per pixel. From this data, a color image is reconstructed by combining the color data from that pixel with the colors from the neighboring pixels. The dirty secret is that the resolution of a "megapixel" camera is thus much less because a nine by nine array of pixels is used to create the color data for each color output pixel.

            • You can use a Sigma DSLR with the IR/dust filter removed. Add an IR pass/Visible light blocker filter in front of the lens and you can make IR photos.

          • Re: (Score:2)

            by ceoyoyo ( 59147 )

            I doubt it would cost more to make a five element filter compared to the current three element ones if it were mass produced. The problem is that camera sensors aren't really very sensitive to IR or UV, almost nobody actually wants that functionality, and it would reduce the effective resolution of your camera.

        • Would it really be that much more than an RGB filter?

          You can achieve RGB filtering by blocking your pixel array on a 2x2 grid, with one pixel unfiltered (for overall luminance), one with a cyan filter (transmitting red), one yellow filter (transmitting blue), and one magenta filter (transmitting green). A square array, for square pixels.

          I you want to go up to R, G, B, IR, UV, you'd need to move up to a 3x2 array, implying that you'd probably need to make your pixels in a 2:3 rectangle (to keep the over all

      • There are already RGB filters on the camera; the sensor only takes pictures in black and white, so an RGGB Bayer array is used to filter the light reaching each photosite. And since there are two G pixels per final pixel, one of those could be switched to an IR filter. That would allow for taking IR pictures (at lower resolution) or mixing in IR in the color photo.

      • I suppose filters could be applied on a per pixel basis in order to make a 5 or more element R,G,B,IR,UV sensor, but the cost would be .... considerable

        In theory, you're correct. In practice, for telescopy, they build sensors with a wide range of sensitivity (well characterised and stable ; probably radiation-hardened too) and deep A:D depths (8 bits for a consumer grade sensor ; 12, 14 or 16 bits for serious amateur to professional telescopy). In front of that you mount a "filter wheel" (or several) contai

        • Re: (Score:2)

          by Lehk228 ( 705449 )
          filter wheels would not fit in a smartphone, and would need to be more than wheels since the RGB channels need to be free of UV and IRso at least those two would have to be independent and able to be engaged with the color filters. fairly trivial on a "let's make one" basis, but very expensive and unreliable to "stick one in every iphone"

    • People use cameras to take pictures of visible light, so the demand for other spectra just isn't there. The simple digital devices have a filter film that can be removed, or replaced for night vision. They are not optimized for night vision so sensitivity is an issue. But it works.
      Depending on where you got your camera parts, they may have a filter, or its possible to do math instead. But a film is cheaper as long as it stays in place
      If you have one, replace it with thin black paper or other things.
      As for w

    • I've always wondered why we can't do simple infrared or ultraviolet examinations of things with our smart phones.

      I have a sneaky suspicion it's because not all clothing is opaque in those spectra, but I like neat science toys, and wish my phone was a little more tricorderish.

      Actually, many digital cameras will pick up infra-red. Try sticking a remote control in front of one - depends on the camera, but a lot of them will show it lighting up.

      • Actually, many digital cameras will pick up infra-red. Try sticking a remote control in front of one - depends on the camera, but a lot of them will show it lighting up.

        Absolutely true.

        A year or so ago I was having problems getting the remote for my new TV to work.

        I ended up confirming the remote worked by pointing it into my digital camera and confirming I could see the IR being sent in a picture.

        Once I confirmed that it was working, it let me narrow down the places I could be looking for my problem.

        Knowin

        • Re: (Score:2)

          by amorsen ( 7485 )

          Infrared is quite a lot of spectrum though. Remotes use the part of the IR spectrum which can be easily detected and generated by silicon-based electronics. Unsurprisingly, silicon-based image sensors can also detect IR remotes.

      • Actually, many digital cameras will pick up infra-red.

        A much more interesting use of the IR capability of a camera is to test the output of your green laser pointers. Green is produced by using a high power IR laser and frequency doubling it into green. The process is not 100% efficient, and if the company saves money by leaving out an IR filter you get a laser pointer that is dangerous in the IR yet invisibly so (except for the green part).

        Here [technologyreview.com] is a summary; This [arstechnica.com] has a more complete diagram of the testing setup.

    • As neat science toys go - I came across plans a while back for passive IR goggles - you replace the lenses in a pair of welding goggles with a combination of theatre gels that block all visible light while allowing IR through. That allows your eyes limited natural ability to perceive IR to operate without being completely drowned out by the visible-spectrum light. It only really works on bright sunny days where the IR light source is sufficient, and you can't see thermal IR at all, but birds look freaking

    • I've always wondered why we can't do simple infrared or ultraviolet examinations of things with our smart phones.

      You could - if the phone were equipped for it. But there's very little call for such capability and no very much use for it if you aren't a specialist, so there's pretty much no motivation for the phone manufacturers to spend the money on more expensive cameras that almost nobody want to buy.

      I have a sneaky suspicion it's because not all clothing is opaque in those spectra

      You're as ignor

    • Re: (Score:2)

      by ceoyoyo ( 59147 )

      You can. You just have to remove the filter in front of the sensor. Astrophotographers have been doing that to their SLRs for years, so much so that Canon released a special (and expensive) version of one of their digital SLRs without the filter.

      Regular cameras have the filter so that the pictures don't look weird. But if you remove it and put on your own IR filter you can do IR imaging. It's difficult though, because the sensitivity of the sensor to IR and the properties of the filter mean you're essen

    • Re: (Score:2)

      by mikael ( 484 )

      You can. You just need the right filters - Hoya H72 comes to mind. You can easily buy a set from the professional camera store of your choice, then you can do your own infra-red photography. It's better buying a set because some filters totally obscure all the infra-red light. The other material of choice is a black plastic refuse bag. That blocks visible light, but the chances are, it is transparent to infra-red light.

      But if you want to do something now, just activate your smartphone camera, find a remote

    • Re: (Score:2)

      by jafac ( 1449 )

      many digital camera sensors are actually pretty sensitive to IR; however, most manufacturers put IR filters on the sensors, because what we want is visible light, when we're taking a photo. I've seen mods on hackaday where someone who wants to do IR photography removes the IR filter on the sensor. (which is doable, when the filter is a separate glass or plastic plate, and not bonded to the surface of the sensor).

  • FTA: Or more commonly, for travellers who want to measure their radiation dose as they fly, since those taking frequent polar air routes between north America and Europe receive a significantly higher dose than others.

    Man am I glad smartphones are finally getting out and about in public. This is the year of the smartphone! Hopefully we'll be able to use them to sense the ambient air pressure while in our submersibles soon.

  • It would work with already taken photos and stored all around internet? along with gps coordinates and date of the photo could give a good use a big (photographic) data.

  • app? (Score:2)

    by CAIMLAS ( 41445 )

    So, if this research has been done and it's been shown to be tenable, where are the apps so we can do so ourselves?

    Presumably they did this on various Android phones and maybe an iPhone or two? I don't see anything in Play.

  • If you have to fly a lot, you're going to fly a lot, whether your phone tells you its bad or not. Neat application of the technology, but not terribly useful to the average joe.

    • I'm sure a lawyer somewhere is salivating while going over airline disclosures... The average Joe may make him a lot of dough.

    • Re: (Score:1)

      by geekoid ( 135745 )

      It could be useful one the data is correlated. Having thousands of sensors constantly detect radiation and different altitude could reveal some interesting things.

      • The data would exist on 1000s of private sensors, so it would be useless in the aggregate. Or are you advocating seizure of the devices and data in the name of sum public good?

  • A few apps exist already (Score:5, Informative)

    by mspohr ( 589790 ) on Monday January 13, 2014 @02:02PM (#45941497)

    TFA states that the "may" release the app but there are already a few gamma radiation detectors on the Play Store for Android such as these:
    https://play.google.com/store/apps/details?id=eu.camdetector.radiationalarm&hl=en [google.com]
    https://play.google.com/store/apps/details?id=com.rdklein.radioactivity&hl=en [google.com]
    Basically you cover the lens with black tape to block light but of course gamma radiation can get through. The apps need to be calibrated to your individual phone since random noise in the sensor can give false readings. The apps provide a method to do that.
    As the article states... the best radiation detector is the one you have with you.

    • Re: (Score:2)

      by jfengel ( 409917 )

      Sorry to be dense (ahem), but why "of course" are they transparent to gamma radiation? Gamma particles have high frequencies, and so more energy, but doesn't the short wavelength make them prone to being absorbed (all other things being equal)?

      IINAP, so I could well be wrong about that, but that was my understanding.

      • Re:A few apps exist already (Score:4, Informative)

        by mspohr ( 589790 ) on Monday January 13, 2014 @02:39PM (#45942123)

        Wikipedia has some good references here:
        "Shielding from gamma rays requires large amounts of mass, in contrast to alpha particles which can be blocked by paper or skin, and beta particles which can be shielded by foil. Gamma rays are better absorbed by materials with high atomic numbers and high density, although neither effect is important compared to the total mass per area in the path of the gamma ray.
        The higher the energy of the gamma rays, the thicker the shielding made from the same shielding material is required. Materials for shielding gamma rays are typically measured by the thickness required to reduce the intensity of the gamma rays by one half (the half value layer or HVL). For example gamma rays that require 1 cm (0.4) of lead to reduce their intensity by 50% will also have their intensity reduced in half by 4.1 cm of granite rock, 6 cm (2½) of concrete, or 9 cm (3½) of packed soil. "
        So, gamma rays can pass through black tape, plastic and glass lenses without much difficulty.

        • Re: (Score:2)

          by jfengel ( 409917 )

          Interesting. Thanks.

          They also pass through airplane skins, presumably. But I wonder how many of the particles that pass through airplanes and tape will also be intercepted by sensors?

          I suppose the only answer needed is "enough to calibrate against."

          • Easily through airplane skins, which are usually constructed of light materials. Cosmic rays are all over the x-ray and gamma spectra, and while you will absorb some, most of the very high energy gamma cosmic rays will pass right through you. However, the increased radiation is easily detectable [youtube.com].

      • Depends on both frequency and energy level.. Of the two, energy level is the one to watch for...very high energies can only be attenuated by significant amounts of solid matter...like a yard of lead or concrete or water (surprisingly, lead is only about 30% max better at shielding than concrete...and a damn sight more expensive and harder to work than concrete.
        Water, of course, helps with neutron radiation too, but I digress...
        But if you're close enough to that kind of energy source your smartphone is the l

    • I've used Radioactivity Counter [google.com] and it works quite well. With a Galaxy Nexus phone, it's about as sensitive to gamma as my GammaScout [gamma-scout.com]. Watch review [youtube.com], or see it in action on a Chernobyl fuel fragment [youtu.be]. But I wouldn't make a habit of exposing a CCD camera to ionizing radiation, because it will damage it [youtube.com].

  • There are lots of ways of detecting gamma rays, but one really common way is through scintillation and/or fluorescence. Most common scintillators are small blocks of plastic. I'm thinking you could increase the sensitivity of the smartphone gamma system by simply taping a small piece of plexiglass to the outside of the camera lens, using plain old black electrical tape. Then the plexiglass would convert some of the gamma energy to visible light and the camera sensor would do the rest.

    Total cost? Probably ar

  • Not for airline altitudes (Score:3)

    by celticryan ( 887773 ) on Monday January 13, 2014 @03:42PM (#45943071)
    The majority of the dose at airline altitudes is from neutrons (55%), with only a small component from photons (gammas are photons) - 5%. This is, of course, on average. I do not think anywhere in the preprint they claim to be able to measure anything but photons. Therefore, a cell phone will not do a great job of monitoring your radiation dose at airline altitudes.

    However, there is a tool being developed by NASA which does a real-time calculation of your radiation dose along an airline trajectory. Check out NAIRAS [spacenvironment.net]

    References:
    Cosmic Radiation @ skybrary [skybrary.aero]
    NAIRAS aircraft radiation model development, dose climatology, and initial validation [doi.org]

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