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ArcticMyst Security by Avery

A Homemade Geigercounter

Joined
Mar 6, 2011
Messages
279
Points
28
Hey Folks,
I've just made a Geigercounter. It's the first I build.
Presently I'm reading the Metro 2033 books, so I think those inspired me ;).
The tube is a SI39G (got it for 15€).
Ther voltage of about 400V is created by a step up converter.
It is possible to use ist between 300v and 600V.
Thats a very simple geigercounter and I belive it only counts gamma radiation.
Some people said the tube ist sensitive for beta radiation too, but I don't think it's much.
The Circuit runs from 5V uo to 9V
I get a zero rate of about 8 or 9 counts.
I've tested the counter using a WT20 electrode. It should contain about 2% thorium dioxide. The counter clicks about 38 times with the electrode beside it.
Building it cost me about 20€ but some time too.
I realized that the most important thing is to have a fast switching time of the transistor to get such high Voltages. Actually the whole setup should be fast (fast diode after the inductance) to load up the Voltage high enough.


Cheers :beer:

so here's a short Video:
 
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Joined
May 9, 2013
Messages
838
Points
43
Pretty cool... now you can measure the dose rate of those U238 doped marbles we all buy to shoot 405's at :)

Thanks for sharing your video... neat stuff!

c
 
Joined
Apr 24, 2013
Messages
549
Points
43
Very nice work.
You can tell if your reading beta by putting a 1/4 to 1/2 inch thick piece of aluminum between the counter and the rod. If the count drops off it's beta, if not it's gamma.
Thorium is mostly a beta emitter but some isotopes put out a fare amount of gamma too.
And some are alpha but you wont get a reading on alpha with a solid tube.
+1 for a great share.
 
Joined
Sep 20, 2008
Messages
17,622
Points
113
Good job on your build. I also built one quite a few years
ago. I used a piece of radio active material that was used
in smoke detectors for testing mine.


Jerry
 
Joined
Mar 6, 2011
Messages
279
Points
28
Hi all and thanks! :)

I have really to get something more radioactive to get a few more clicks.
What a pitty that I dont have any of those marbles or any other radioactive materials.
May I find something on a flea market. I bet there are old watches or some things out of uranium glass.

I put the rod in a 1,5mm thick stainless steel tube.
The result was about 2/3 of the clicks I got without the tube.
 
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Joined
Oct 14, 2011
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Hey mrmcchicken! I can send you some marbles for free :) i curious how your build works with them as i find it very cool!

Pm me :)

Greetings,,
 
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Joined
Mar 6, 2011
Messages
279
Points
28
I've sent you a pm.
That sounds really great, thanks a lot for this offer! :)

Greetings
 
Joined
Oct 14, 2011
Messages
2,369
Points
83
Marbles are heading towards you :beer:

BA022F19-6F76-493B-B186-6BEE6456040E-5758-00000381DEC7AED7_zps7aa4c0bf.jpg
 
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Joined
Apr 24, 2013
Messages
549
Points
43
Hi all and thanks!
I put the rod in a 1,5mm thick stainless steel tube.
The result was about 2/3 of the clicks I got without the tube.

Sounds like Beta and Gamma.
Don't know if you can get radioactive stuff sent to you, but if you look on ebay for Thorite you'll find some inexpensive offers.
I got one piece that puts out 10,000 counts per minute.
Note: I'm running a scan on one of the 1" marbles and have so far seen a high of 135cpm to a low of 46cpm.
So don't let the kids play with them or carry one around in your pocket.
Ed
 
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Joined
Mar 6, 2011
Messages
279
Points
28
Yes, from me +1 too if I can! :)
If the Marbles are here I will do a measurement as soon as possible and write here about it.
I think I'll make a short video too.

@ Flaminpyro: I think this isn't such a good idea. This stuff could easily lay around everywhere ;).

Edit: I got the Marbles today.
Thanks a lot those are amazing!
They look really great. :).

And I think I have some good news. They aren't as much radioactive as the electrode I've tested.
I get about half the clicks up to 20.
Both thogether beside the tube make more then a click each second average, so it is hard to count,
but I am working on a circuit which counts the clicks

Thanks a lot all :)

:beer:
 
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