Radiation detector, help needed!

98 thoughts on “Radiation detector, help needed!”

1. I can’t believe no one has mentioned a MOSFET yet. There are several papers published on using the device as a radiation dosimeter.

   The incoming radiation creates excess electron-hole pairs in the MOSFET base. If it is under bias while being irradiated, the radiation is seen as a change in the threshold voltage of the device. It’s also a perfect integrator, so long as it’s kept under bias (separating the holes created from recombining). They are small, cheap and will do what you need them to.

   Diodes work, but are a little tricky; their usefulness is dependent on the angle of incidence. TLDs pose their own problems – use the MOSFET.

   I’m willing to share my thesis, as I said; let me know how.

2. I wonder if there is some way to use a blackend CCD from a cheap web camera to detect secondary ionizing effects. Temperature would probably effect the results so a temperature sensor would also be needed to select the right conversion table.

3. Here’s a clever and low power consuming step up converter for gm tubes: http://www.mikrocontroller.net/attachment/103170/Geiger_Hochspannung.png

4. This seems to be interessting:

   http://www.google.fr/url?sa=t&source=web&cd=1&ved=0CB0QFjAA&url=http%3A%2F%2Fwww2.fpm.wisc.edu%2Fsafety%2Fradiation%2Fdocs%2Flsc_guide.pdf&rct=j&q=Principles%20and%20Applications%20of%20Liquid%20Scintillation%20Counting&ei=2daDTYT1F8WEhQeT4fzSBA&usg=AFQjCNGLjE2_t6M56nJ5UCkbTd6_Eg7H5A&cad=rja

5. Hi man,

   I”m glad you had this idea, i’m searching some documentations that could help developpers understand all this stuff is working here are the direct links to what i found:

   Radiation Detection and
   Measurement :

   http://depts.washington.edu/uwmip/Week_2/Rad_detect_and_meas_LRM_Summer06.pdf

   Nuclear Physics and Radiation Detectors:

   http://www.physics.gla.ac.uk/~kaiser/p4h/nuclear-lecture-01.pdf

   Other ressources can be found on Google if you look for :

   “nuclear detector:pdf”

   Good luck

6. Try sfh205/6 PIN diode. You get few mV pulse per particle detection, active area 7mm2. You need a fet opamp to apmlify. It works (bonus-the pulse level is proportional to the detected particle energy, what is not the case with GM). Miro

7. There is a Yahoo group discussing this topic since 2003: http://tech.groups.yahoo.com/group/GeigerCounterEnthusiasts/

   Welcome to the Alpha Beta Gamma Society.
   This group is for amateurs interested in building, collecting, repairing, modifying, discussing, and learning about Geiger Counters and other Radiation measuring equipment.

8. It is possible to use high voltage converters from
   photo flashes for GM tubes.
   I did this and it worked perfectly.
   You get those modules sometimes for little money, or
   you could just buy a cheap disposable camera with
   flash.
   Here’s a tutorial for diy geiger tubes:
   http://www.rapp-instruments.de/Radioaktivitaet/Detektoren/Geigercounter/Geigercounter.htm

   Unfortunately it is in german, but it should give an idea.
   They are just using copper or aluminium tubes filled with common argon/co2 gas for welding.
   Those tubes need a higher voltage than common gm tubes, so they used a power supply from an old laser printer.

9. to get an accurate cpm an active quenching circuit should be used, a simple design and explanation be found here

   https://docs.google.com/viewer?a=v&pid=explorer&chrome=true&srcid=1SSfowrd_lx2xcaHYy4IX2F480kdahEfnQmdp2P0y0T-Z82Par4saepEAWD-7&hl=en&authkey=CMy8rJ8C

   a good design i found using an sbm-20

   http://brohogan.blogspot.com/search/label/Geiger%20Counter

   a really good source on information for geiger tubes and driver circuits can be found here, its mostly for cosmic ray detection and radioscopy but its a good amount of information

   http://www.hardhack.org.au/book/export/html/12

10. I just finished a thesis based around the design of a radiation dosimeter for implantation. My constraints were that the device had to be very tiny – I’d be happy to share a bit of the paper with you guys if I can do so by e-mail – let me know how! I’ll check “Notify me of followup comments via e-mail”

11. I have a sparkfun detector node setup at http://www.twitter.com/geiger93933 (marina, ca) that id like to add to any monitoring network.

12. Take the circuit example as already shown above: “To measure the level of γ-radiation, consider this chip: http://www.maxim-ic.com/app-notes/index.mvp/id/2236”
    You don’t need to use the mentioned op amp, just take a low noise type. More important: as detector diode, use a BPW34 and cove rit with black tape to block light.

13. I made a dosimeter for an embedded systems course two years ago. I used a $20 geiger clicker from Ukraine as a source of interrupts.

    I found the volume of the the tiny geiger-muller tube, averaged ionization events over 1s, 10s, and 300s in cyclic buffers, and used the average energy of alpha and beta particles to calculate the dose.

    It’s difficult to get a true reading, so I used the background radiation from my area to calibrate it.

    I can help with all the embedded code, but the geiger-muller tube circuitry was taken from a cheap analog Russian handheld clicker.

14. How about modifying Smoke Alarms so that they work in reverse? – one type works by a small amount of americium emmitting ions, causing a current to flow across a gap and then detecting this current. The smoke absorbs the ions, and blocks this current. Remove the americium and the only source of current would be the outside ionizing radiation.
    Karl

15. I also thought about building a radiation counter but as already pointed out using solely semiconductors. This company provides PIN diodes specifically for radiation detection but no word about price or availability.
    http://www.ssdi-power.com/Catalog.aspx?id=127
    Never the less a more off the shelf diode should also work. Important aspects are sufficient size of the depletion zone (this is the actual detection area) and capacitance of the diode.
    Another important aspect to such a circuit is a very good low noise pre-amplifier with small input capacitance.
    Big advantages to PIN over GM are small size, low voltage, higher robustness and easier interfacing to uC.

    My 2 cents

16. hmm…. what type of radiation you want to measure?
    somwhere i had read what simplest detector is starter from fluorescent lamp 😉

17. Nuclear war survival skills Chapter 10 – http://www.oism.org/nwss/s73p921.htm

    The Kearny Fallout Meter is an accurate and well tested device designed for civil defence that can be built by anyone. Let’s not reeinvent the wheel or anything…

    http://www.oism.org/nwss/s73p938.htm is the appendix which has the actual ‘how to build’ portion.

18. While this is certainly a cool project idea, it should be important to note that any radiation detection equipment built “on the cheap” should only be used for educational or entertainment purposes.

    Industrial detectors require strict manufacturing tolerances, with extremely sensitive materials and electrical circuits. On top of that, they need to recalibrated fairly frequently to maintain accurate readings, which is further complicated if you’re working within a single magnitude of background counts. So, unfortunately, anything falling within the scope of this project would be too inefficient to be useful in any real sense.

    A dosimeter would be much more useful if you’re actually concerned about radiation. Although I will be the first to admit that they are far less exciting, haha.

19. Someone in the suburb of Tokyo has been doing this for some time.

    http://park30.wakwak.com/~weather/geiger_index.html

    He is using GM-10.
    http://www.blackcatsystems.com/GM/GeigerCounters.html

20. Here is an app note from microsemi that uses PIN diodes UM9441 & UM9442 as radiation detectors.

    http://www.microsemi.com/brochures/pindiodes/appendix%20f.pdf

    They have included characterization curves etc.

Comments are closed.