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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If it is not news, then how is it this guy is the first to market with a device that will fit in your pocket?
Did you even read TFA?
Re:Not news. (Score:5, Interesting)
Perhaps it is because a beta radiation detector is useless if it is in your pocket.
Beta radiation detectors in general don't have a lot of use in the field because there is always gamma radiation with beta radiation. And small gamma detectors already exist, such as the digital electronic portable dosimeters workers at nuclear plants use. If there is a question about beta dose, these same workers have thermoluminescent dosimeters with beta windows that can be analyzed on-site. If you actually need to survey an area, you can always use a beta-gamma dosimeter, but you would only do that if you were health physics tech.
There is no real use for this device.
Re:Not news. (Score:5, Interesting)
Beta particles (electrons ejected from the nucleus, basically) have a mean free path of about a foot in air. Place anything else in between, like a thin sheet of aluminum or a little bit of plastic, and it sucks up the betas real quick.
The other big problem is that gammas are quantized, beta particles are not. When something radioactively decays, it gives off gamma rays of distinct, unique energies -- very useful for determining the radioactive isotope you're looking at. Not so for betas; they're emitted over a wide range of energies, and it can be very difficult (but not impossible) to tell what you're looking at by betas alone. I don't mean to downplay what this accomplishes, in a nice, small form factor. But this doesn't revolutionize the world of radiation detection. To date, no one has really been crying for a combined, digital, gamma and beta detector. Maybe if you build it, they will come, but I don't see a large market for this.
Re:Not news. (Score:5, Informative)
The (now grand)parent should be modded up, but one thing in your post is just plain wrong: the range of beta radiation is not "about a foot"; the range of beta radiation depends on its energy. Betas from a low energy nuclide like 35S, for example, do have a range of almost exactly a foot (32 cm) in air, but the high energy beta radiation emitted by 90Sr/90Yr OTOH has a range of slightly above 10 meters in air. And as for the quantization, beta emitters too have very distinct energy distributions (which you can look up in any good data sheet).
But you're right about portable beta spectrometry being pretty "meh". If it's high enough energy to worry about, it's easier to just look at the bremsstrahlung, really.
BTW, this was a really horrible article. There were no technical details whatsoever (well, just enough to realize that someone had been trying to explain scintillation to the very obviously non-techie journalist), and they seem to mix up radiation spectrometry with plain radiation detection...
At first I thought we had GNURadio at the giger co (Score:2)
Agreed. At first I thought we had GNURadio/USSP at the giger counter wavelength.
After reading the articles I'm none the wiser.
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GNURadio [gnuradio.org] is so powerful yet so poorly documented. The USRP2 hardware is wicked-expensive (and now end-of-life), but really powerful. The N210 is its replacement.
Electrons and Photons are both quanta (Score:2)
The other big problem is that gammas are quantized, beta particles are not.
Actually both are quanta of their respective fields and, as free particles, neither have quantized energies. However gammas tend to have discrete energies, whereas betas do not due to the neutrino emission.
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Beta radiation detectors in general don't have a lot of use in the field because there is always gamma radiation with beta radiation. And small gamma detectors already exist, such as the digital electronic portable dosimeters workers at nuclear plants use. If there is a question about beta dose, these same workers have thermoluminescent dosimeters with beta windows that can be analyzed on-site. If you actually need to survey an area, you can always use a beta-gamma dosimeter, but you would only do that if you were health physics tech.
There is no real use for this device.
FTFA:
Each kind of radioactive material produces different ratios of gamma rays to beta particles, and so from the signal one can tell what it is. A basic use for the detector is to see whether a soil sample, for example, is contaminated with anything radioactive. It could also be used to check whether a given area is worth mining for elements such as uranium.
Their claim is that the beta/gamma ratio (which it detects) is useful. Are you saying it is not?
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Their claim is that the beta/gamma ratio (which it detects) is useful. Are you saying it is not?
If all it does is detect the ratio then it is close to useless. Suppose there are three elements A (gamma only), B (beta only) and C (gamma+beta). If all I can do is detect the ratio of betas to gammas then it is impossible to distinguish between material that is 100% C vs. material which is 50% A and 50% B.
Fortunately nature provides a solution and if you measure the energy spectra of gamma rays it will very quickly tell you which elements are present. So, as described in the article, the device seems
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Exactly, let me know when they come up with a handheld neutrino detector.
Geiger-Muller (Score:2)
Geiger counters can detect all forms of ionizing radiation. They're over 100 years old, too.
Which given off by rip in time-space continuum? (Score:2)
We must preserve the Time-Space continuum!
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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.
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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.
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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
Sounds like the ideal tool (Score:2)
...to carry through post apocalyptic waste lands.
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Sounds like the ideal tool...to carry through post apocalyptic waste lands.
Because it is vitally important to know whether you are suffering radiation sickness from beta vs. gamma radiation?
Yes, but... (Score:2)
I'm waiting for the model that tells me when radiation will reach lethal levels. To the second if possible.
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More importantly, what episode(s) did Dr. Who use the sonic screwdriver to detect radiation?
I don't remember any...
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He's used other devices for detecting stuff (eg: the time scanner in The Chase, the Guardian's detector in the Key to Time series, the blinky-lights-thing in the Pillsbury Doughboy episode) but I've never known him to use the sonic screwdriver to detect radiation.
Bad bad article and summary (Score:5, Informative)
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
http://oregonstate.edu/ua/ncs/archives/2010/dec/new-technology-speed-cleanup-nuclear-contaminated-sites-reduce-costs-and-create-jo
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.
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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.
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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.....
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here you go:
http://www.best-geiger-counter.com/geiger-counter-kit.html [best-geiger-counter.com]
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.
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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
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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.
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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
Does it (Score:2)
Detect Neutrinos?
How about tachyons?
Midiclorians?
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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.
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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.
Use an Image sensor (Score:1)
Yeah, yeah, yeah, but... (Score:2)
Will it tell me what kind of alien leaves a green spectral trail and craves sugar water???
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Zed, we have a bug.
The linked article is stupid (Score:1)
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 (http://www.canberra.com/products/13452.asp).
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
more importantly (Score:2)
is there an iPhone app for this yet?
kinda tricky... (Score:2)
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.
TSA has had them for at least 4 years. (Score:2)
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.