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Radiation Detection Goes Digital 58

RedEaredSlider writes "In science fiction, explorers wave around a single device and pick up many kinds of radiation — think of the tricorders on Star Trek or Dr. Who's sonic screwdriver. A professor at Oregon State University is bringing that a bit closer to reality, though in this case it's for finding radioactive material. It's a radiation spectrometer, and it works on a very old principle: particles and photons that hit certain materials will make them emit flashes of light. But for decades, radiation spectrometers had been limited to detecting only one kind of radiation at a time. David Hamby, an OSU professor of health physics, felt that there was a need for a device that could see at least two kinds of radiation, as well as be smaller than the models currently available."
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Radiation Detection Goes Digital

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  • Geiger counters can detect all forms of ionizing radiation. They're over 100 years old, too.

    • by icebike ( 68054 )

      Geiger counters are used to detect radiation (usually gamma and beta radiation, but some models can also detect alpha radiation).

      Geiger-mueller counters respond to the commonly encountered types of radiation, namely, alpha and beta particles as well as gamma and x-radiation. However, GM counters cannot determine the type, energy, or vectors of the detected radiation.

      They are generally much larger than this device and provide little in the way of discrimination by type.

      • Geiger counters are used to detect radiation (usually gamma and beta radiation, but some models can also detect alpha radiation).

        Since they detect the ionization of gas in the chamber they are all extremely good at detecting alpha radiation, which is the most highly ionizing form of nuclear radiation. The only issue is that it is so highly ionizing the tube will need a thin window to let the particles in. They are also generally poor at detecting gamma radiation since that is less ionizing that beta.

    • Geiger counters do detect ionizing radiation, but do not differentiate between isotopes, hence they are not useful for spectrometry.
    • in practice, there's a problem with alphas, which have to be energetic enough to penetrate the tube walls. They're best at beta detection, while gammas have low efficiency as most will just zip through undetected. For "indirectly ionizing" radiation, neutron fields, one has to have a usually large volume of material that will produce ionizing radiation when neutron interacts. For example, a few tens of centimeters diameter ball of plastic and scintillating material which works by proton recoiling from neu

  • carry through post apocalyptic waste lands.

    • Sounds like the ideal carry through post apocalyptic waste lands.

      Because it is vitally important to know whether you are suffering radiation sickness from beta vs. gamma radiation?

  • I'm waiting for the model that tells me when radiation will reach lethal levels. To the second if possible.

  • by tastiles ( 466054 ) on Monday January 03, 2011 @07:49PM (#34749140)

    As a physicist that works with radionuclides, I'm appalled at this article. It is horribly written. "The crystal vibrates in a certain way" made me laugh.

    A better summary is provided by OSU public relations dept at

    Radiation detectors have been digital for a long long time. Some of the electronics has been analog because analog electronics are faster and always will be for filtering and integration.

    • Agreed.

      You can buy *digital* pocket sized radiation detector kits for $100. People have sent these digital detectors up to space in high altitude balloons a thousand times already, including me. Even sparkfun sells one.

      • those usually have wimpy range though, a few mRem per hour....pfffft, I worked at a nuke plant, we'd call that the cafeteria 8D

          show me the 0-1000 rem / hour survey model if the world goes mad max.....

        • here you go:

          I'm currently using the Electronic Goldmine Geiger Counter Kit, with a microcontroller to process and datalog the events. The specs aren't well defined, but if I put a smoke detector (the radioactive part) next to it, it goes absolutely crazy.

          Sure these units are very limited, but technology wise the same.

          • those are cool, remember though that geigers are for prospecting or for testing for contamination after being in rad area - radioactive dirt and dust. Tens of thousands of counts per minute, in other words some might go to 10K cpm which is very roughly 100 mR / hour. For the heavy levels, like nuclear accident or The Day After, the survey meters work on a different principle. Those are the ones that can go to 500 Rem / Hour or more, that level for about an hour would give you lethal dose without "heroic

    • by Anonymous Coward

      Yup - I work at a company building such devices. He's describing pulse shape discrimination for the signals output by the crystal. While you can get quite a bit done with analog electronics, ASICS and FPGAs have gotten good enough to do quite a bit of sophisticated processing, and have been fairly standard for some time now.

    • by jd ( 1658 )

      For identifying radionucleotides, you're generally looking for combinations of energies. You can probably get better identification by also looking for daughter radionucleotides and other characteristics. However, even the very very basic expert system I cranked out as a teenager (you entered the list of energies, it churned out a list of the "best-fit" set of radionucleotides that would produce such a pattern) was able to correctly identify each and every isotope present in the Chernobyl fallout and gave o

  • Detect Neutrinos?

    How about tachyons?


    • The folks at CERN have one that can detect Higgs bosons. Um, however, it's not that quite portable yet. So you might want to bulk up in the gym before trying to carry it around. And you need a tank of liquid helium on your back. Oh, and if you detect a Higgs boson, give it some press, a lot of folks are interested.

      • The folks at CERN have one that can detect Higgs bosons. Um, however, it's not that quite portable yet.

        The Higgs boson, if it exists, has a mass over ~114 times bigger than a proton. ALL that energy goes into the decay which means that the decay products will have energies about 1,000-10,000 times higher than those from nuclear decays (10's GeV not a few MeV). Since all detectors work on the principle of particles depositing energy in material as they pass through it with several thousand times the energy you need a lot more material hence a far larger detector.

  • Could you use an imaging sensor chip to detect radiation? something like this video, only more refined. []
  • Will it tell me what kind of alien leaves a green spectral trail and craves sugar water???

  • by Anonymous Coward

    Radiation detectors that can differentiate between two types of radiation have existed for a very long time and digital systems that can differentiate between alpha, beta and gamma radiation have existed for at least the last 3 years which is when I started working with them (

    Granted, those systems are rarely spectrometric systems and only a few are small enough to fit in your pocket.

    The article does not actually say how the system works but my guess is that it is

  • is there an iPhone app for this yet?

  • Bringing up the doctor isn't fair, there's probably some hyper-spacial sensing and processing machine the size of Manhattan inside the sonic screwdriver using Time Lord Technology (tm), and you simply can't tell from the 3-D part. The real problem is simply trying to detect and analyze different kinds of radiation. Look at the difference between a radio-telescope and the Chandra space telescope.

  • about the size of a pager or a basic clamshell phone, and they can distinguish between different isotopes. I know, I got pulled over and scanned (undisclosed period) after a radiation cardiac stress test.

Can anyone remember when the times were not hard, and money not scarce?