Photodiode Gamma Ray Counter

Pocket-sized gamma ray counting detector based on the BPW34 photodiode, PN4117A electrometer JFET and LM358 op-amp. Pulls about 1 mA quiescent (i.e. when not flashing the LED).

http://www.vk2zay.net/article/265

Less sensitive than an average Geiger-Müller tube, perhaps about the same as those tiny dosimeter tubes. Vastly cheaper (at current eBay prices) and easy to build however. Also offers rudimentary spectrometer capability with a MCA circuit - work in progress.

Category:

Science & Technology

Tags:

• vk2zay
• geiger counter
• geiger müller
• photodiode
• gamma ray
• thorium
• uranium
• americium

[The666knives]

excuse me for asking.i am trying to do the same thing.for the photodiode dosimeter, what kind of filter did you use?aluminium foil?where did you get the gamma ray source?the photodiode idea for a detector is brilliant! excuse my english.i'm romanian,thank you verry much, and good luck in your future projects!

[vk2zay]

@The666knives the window over the end of the tube is a very thin piece of brass shim stock. I have used normal Aluminium kitchen foil and tinplate, both work, the Aluminium gives the lowest attenuation, but there is little difference and the brass and tinplate can be soldered easily.

The various sources I've collected from a number of different places. The Am comes from a smoke detector, the Th and U from eBay and hardware stores.

[vk2zay]

OK peoples, I see votes for continued videos on radiation experiments... :)

[Albinorama]

cut your nails, please.Thanks.

[vk2zay]

@Albinorama Whatever would I adjust the cermet trimmer with if I did? An amusing story on this actually, the temperature stability of this circuit is poor, this rather cold morning I did infact cut my nails (long before I read this comment BTW) and as a result had great difficulty stopping the thing going nuts in my bag on the bus. I got all kinds of strange looks from fellow passengers who only see "geiger counters" clicking madly in movies!

[Photonface]

We will only be sick of your radiation experiments when you have melted away your stomach lining and start puking up blood. Before that however keep doing more experiments. By the way could you post the schematic for this gamma counter on your site please. Love your site mate.

[mkmalm]

What are you using as a window for the photo diode (the tube under the breadboard)? Al? Nice job... looking forward to the MCA circuit.

[TheCrazyInventor]

How can anyone get sick of this stuff... I love it!

Youtube should have more of this type of experimental/electronics content. :)

[orbiter8]

Nooooo.... Not 'sick of it' at all mate. In fact exactly the opposite. Please do feel free to keep the camera rolling whatever you're doing.

[xXdenhartXx]

Sick of it? No i freaking love it! Please keep it up :D