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Registered Member #2063
Joined: Sat Apr 04 2009, 03:16PM
Location: Toronto
Posts: 352
just made a TL494 flyback driver, suprising it works better on a lower duty cycle then I connected the output of the flyback to a thermionic diode and i can see the glass wall of the tube glow blueish does that mean the glass is absorbing some of the x-rays?
whats the cheapest geiger counter for sale? i've looked on ebay and the cheapest ones are 150$ are there cheaper ways to get a geiger counter that can detect x-rays?
Registered Member #1438
Joined: Sat Apr 12 2008, 12:57AM
Location: Canada
Posts: 218
Geiger counters are not too reliable at detecting the true amount of radiation being outputted by an x-ray tube or any tube creating high amounts of ionizing radiation; due to the fact that Geiger tubes need to be quenched which produces a dead time.
As for buying cheap geiger counters, the cheapest are usually low end geiger counters like a Kvarts DRSB-88 which costs about $29-39 USD. If you want a geiger counter with a digital readout, I recommend making yourself an arduino geiger counter using cheap SBM-20 tubes. Purchasing a geiger counter with digital readout usually costs upwards of $100USD.
You should preferably either buy a geiger tube which has the shortest dead time (fastest quenching) or an ionization chamber. With these things said though, you always have adequate shielding such lead when playing around with tubes and high voltage.
Registered Member #96
Joined: Thu Feb 09 2006, 05:37PM
Location: CI, Earth
Posts: 4062
Tried to send a reply and my internet went Strange Loop.
I'd use a cheap Geiger tube with a pair of magnets axial to the tube, a good source is defunct Zip drives. Another trick is to get a surplus B/W B&Q camera with the 6 IR LEDs and then gut it, add a pyrolytic filter and then lightproof it. Good for several months if properly sealed and dried I also added a variable clock to mine, so it can be switched between normal visualiser and high sensitivity.
Interestingly enough alphas get through the graphite that it looks like a snowstorm on the sensor with a typical piece of thorium weldng rod or Am241 source. Haven't had a chance to use my radium clock, as the sensor failed due to moisture eating the bond wires
Registered Member #1438
Joined: Sat Apr 12 2008, 12:57AM
Location: Canada
Posts: 218
Conundrum wrote ...
Interestingly enough alphas get through the graphite that it looks like a snowstorm on the sensor with a typical piece of thorium weldng rod or Am241 source.
There's actually a pretty good example of that effect here The americium snowstorm starts at 3:04
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cheap geiger counters?
