Hackaday Prize Entry: An Open Radiation Detector

For his Hackaday Prize entry, [Carlos] is pushing the boundaries of what can be built with PCBs. He’s designed a very low-cost radiation detector that leverages pick and place machines, off-the-shelf components, and very simple electronics. It’s a novel ion chamber design, and if you ever needed a low-cost, easily manufacturable radiation detector, this is the project you want.

Instead of a Geiger tube or a spark detectors, this radiation detector uses an ionization chamber to detect radiation. This project was inspired by the work of [Charles Wenzel] and [Alan Yates], and the implementation is actually pretty simple. A metal can — or some other type of enclosure — is electrified, and a single wire is stuck right into the middle of the can. When alpha and beta particles enter the can, air molecules are ionized, and attracted to either the can or the wire by a difference in voltage. A tiny bit of current flows between the can and the wire, which can be detected if you have a sufficiently sensitive circuit.

The basic idea is well-publicised and well-understood. What [Carlos] is doing with this project is making an ionization chamber easily manufacturable. He’s doing this entirely with standard PCBs and solder instead of paint cans, RF connectors, and deadbugged transistors of the earlier experiments. The resulting PCB actually looks like something that wasn’t put together in a garage (even though it probably was), and is an amazing entry for the Hackaday Prize.

38 thoughts on “Hackaday Prize Entry: An Open Radiation Detector

      1. Yes, you’re right. Vacuum required. The one I was thinking of was a neutral mass spectrometer on the DANDE student satellite. So vacuum is a given when deployed.

        http://spacegrant.colorado.edu/boulderstudents/boulderprojects/dande

        So in that case there’s current source for ion field (to ionize neutral particles entering), variable E-field to bend trajectory of particles, and then a plate with positive feedback (to amplify charge of impinging particles) which feeds to detectors. It was made with machined parts but probably could leverage some trickeroer here to make it simpler/cheaper.

        Then for terrestrial application could be used in a cheap bell jar.

        And then boom – a low-cost spectrometer of sorts.

        I’m sure there’s a ton of stuff I’m not thinking of though.

        Cheers,
        Brandon

        1. That would be really fun to explore. I have tons of gear and just need a couple students who want to use it.

          You can use a constant E-field and the amount of bend is from mass if you have some kind of linear array at the collection end. That might be not so hard now. Variable voltage must be to sweep the ions across a single electrode?

          Maybe more fun and in some ways easier is a time-of-flight mass spec. E-field is fixed and is end to end of a tube to accelerate ions in bursts. Arrival time is proportional mass and charge. They are very sensitive because they get all the ions and they are very precise because both the accelerating voltage and the distance can be measure so easily. Hmmmm. What a cool project! In the old days they used a Tek storage scope and a Polaroid camera to collect data.

          1. Yes I agree it would be fun to explore!

            And yes you’re right it was for a single electrode, and there was a linear array in the orthogonal direction, as in the case of the satellite the entry direction was of interest. And the opening was controlled geometry to allow preservation of direction in one dimension only.

            And very interesting! I hadn’t thought of some the approaches you describe (although we did use the Tek scope approach before the electronics were functional) – but they make sense and are cool to know about.

            So since the project was University-based I’m thinking I could probably share the schematics/design here. I’ll see about grabbing them.

            Cheers,
            Brandon

    1. Well current world circumstances could have something to do with it…but it could also be that these are relatively straightforward projects that allow us to detect the unseen world around us.

    2. It’s something we absolutely cannot pick up with our senses, yet it can be dangerous if there’s enough of it, so it obviously draws attention. That and the mass hysteria about radiation now.
      And from the hacker perspective, radiation is a neat phenomenon to study. Can’t study something you can’t perceive without instrumentation…

    3. Indeed, good question. If the maker community is a good subset of society at large, you could ask why society is so obsessed with radiation? Even the most recent large accident is 6.5 years ago and had no human fatalities. The earthquake + tsunami that had 15.000+ fatalities somehow always gets ignored when the scaremongers strike.

      1. “and had no human fatalities.”
        I can see why you (and friends) would be against those annoying people that have the a capability to counter any BS ‘official’ statement.

      2. Well then, looks like there is opportunity for a ULF/ELF/VLF project and the other teams can focus on UV/X-Ray/Gamma/Cosmic/?? name higher than cosmic EMF/EMS and particle radiation.

        Maybe for projects in automated with backup servers and maybe hard copies for data entry and statistics also. With validation and validated systems may I add.

        Look out… incoming B.S. official’s!

        Can I say something like… “the death of one is a tragedy”… “the death of millions in a few years before their natural time prior to a certain event is just a natural cause of death statistic you see?” Oh, boy… :-(

  1. Just a thought – has anyone tried using an ionization smoke detector as a low-cost sensor? Remove the radio-isotope and you have an ionization chamber with the basic electronics too.

    1. Makes a fairly good disaster warning…ion chambers are naturally not very sensitive, so unless you expose it to a fire or some other source of ions, no false positives from non-radioactive stuff.

      For example the the czechoslovak-made IT-65 intensimeter uses both a GM-probe and an ion chamber. GM-probe is good for lower activity work (like checking if clothes or the people wearing them are contaminated before you let them into a shelter) and the ion chamber comes into play when the GM probe pegs the scale at 0.5R/h.
      While not exactly safe by any standards, even hours in such conditions should leave no short therm effects. But without the ion chamber, you wouldn’t know if it’s just 0.5R/h(not too bad) or 50R/h (bad) or 500R/h (really bad), the needle would be smashed into the right peg and audio output at a constant scream.

      They’ve had problems exactly like these after the Chernobyl incident, the sensitive instruments used to detect weak sources under normal conditions and such were now useless, because near the incident site they were all just reading full scale all the time, making them useless.
      You couldn’t tell if it was just a bit of dust from the reactor in the grass (considering the situation – fairly harmless) or a sizeable chunk of the reactor core (quite deadly at close range).

    2. It’s clearly a work n progress. The BG radiation measurement fails due to ambient temperature they say, and you’d think someone would eventually find a fix for that.
      Obviously you can’t thermally isolate it without blocking a signal, but what if you for instance get the amplifier isolated, perhaps you can use a vacuum? There’s work to be done yet and I don’t think giving up is in order yet.

      1. Hope they will find out a good solution. It will be nice to have one more option, other than very expensive and hard-to-find PiN diodes or russian GM tubes form USSR times (one day stocks with russian tubes will be out).

    1. Interesting idea, not sure if piezo fog particles are small enough though…. and also every piezo humidifier I’ve had has barely lasted the warranty, so I don’t regard long term reliability as very good.

    1. Radon is a known killer (statistically), and enters every home near the ground.
      Such is nature.
      But biological systems are ‘aware’ of various sources of danger and have mechanisms to repair and reject even damaged DNA.

        1. You could burn some incense as smoke seems to help:
          http://www.techlib.com/science/secondhandsmoke.htm
          Also, the radioactive dust produced from the decay of radon seems to stick to electrically charged things like the screen of CRT televisions. Try wiping a damp folded up tissue on the CRT just after it has been used for a few hours, then hold the tissue in front of a mica window geiger tube and you will probably get a good reading, depending on the radon level where you are. The half-life of the dust seems to be short, less than a few days. It seems to me that collecting the radon on the screen must be good for the humans nearby, because whatever is stuck to the CRT is not in your lungs. Maybe the shift to LCD televisions will bring increased lung cancer.

      1. are you sure? “ion chambers” conventionally denote detectors without intrinsic multiplication mechanism, so the generated charges do not accelerate and knock out new charges. I wouldn’t know where to start to electronically measure individual electron charges without intrinsic multiplication (as happens in geiger counters, or as happens in scintillators for gammas)…

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.