Geiger Counter Question?

[YT2095]

I bought a Geiger Counter a few years ago, It was a kit costing about £70.

I`ve had it tested by a friend of mine at Birmingham Uni, and she wrote a rough list of test results, It`s almost deaf at Alpha radiation, better response at Beta and works just fine at Gamma.

that being said, I was wondering WHY it goes absolutely balistic when I put it near my plasma ball or my Tesla Feild generator?

I`ll get counts from over 3 feet away!

anyone have any ideas what may cause this?

[greg1917]

If it works better at beta and gamma then range will make very little difference due to the nature of both types of radiation.

[YT2095]

so what do ya recon`s going on with it then?

I`ve even tried sheilding the electronics (tin foil) with only the Muller tube exposed, same result? and I can`t beleive that a simple plasma ball you can by from any lighting or gadget shop would create Gamma or Beta rad

[Morrgan]

I thought range does matter with a Geiger Counter. Have I misunderstood something?

[Dave]

Range matters when you're measuring radiation. Gamma rays follow an inverse square law, alpha particles can't travel more than a few cm before being stopped by the air, and I'm not too sure about beta particles but they follow the same kind of pattern.

 

The only think I can think of is that maybe the plasma ball is causing some of the air around it to be ionized, and because Geiger counters work because the radiation ionizes the particles inside the tube, it's causing it to go haywire.

 

I have no idea whether I'm right or not though.

[YT2095]

I`de say that sounds about right to me, it has to be active ions though, because it stops instantly when you turn the power of the plasma ball, still leaving ionised air but probably not suficiently charged?. I experimented with an air ioniser (the sort you can get for cars) and that has the same effect. then I tried UV exposure into the tube, it did nothing.

so if it isn`t the ionised air, then maybe it`s the particles that ionise it the 1s`t place that are responsible?

I`ll wait till go out next and pick up some lead sheilding (roofing lead) and see if that makes any difference

 

thnx for the input so far

[swansont]

YT2095 said in post #1 :

I bought a Geiger Counter a few years ago, It was a kit costing about £70.

I`ve had it tested by a friend of mine at Birmingham Uni, and she wrote a rough list of test results, It`s almost deaf at Alpha radiation, better response at Beta and works just fine at Gamma.

that being said, I was wondering WHY it goes absolutely balistic when I put it near my plasma ball or my Tesla Feild generator?

I`ll get counts from over 3 feet away!

anyone have any ideas what may cause this?

 

Your plasma ball is giving off X-rays. Very "soft" ones (i.e. relatively low energy), to be sure, so I'm a little surprised that it sets off the Geiger counter, but I suppose it's possible.

[YT2095]

Soft X-rays... Hmmm, I`ll have to try a photo plate test in that case, using different blocking media.

Just gotta wait untill next payday to buy some film, then find a place that will develop single frames (might take some time).

[aman]

I wonder if putting your geiger counter in a bag full of helium would protect it from the effects of the ionization of the air.

Just a thought.

Just aman

[aman]

I just found this site if you want to calibrate yer counter.

here

Just aman

[YT2095]

Aman, thnx anyway, nice thought

but this counter really is a simple one, there`s nothing to callibrate in all honesty, it was kit, with the PCB and all the parts that you solder into place, there`s nothing adjustable on it at all

even the bleeper for a count is a fixed tone peizo module!

the only thing I may be able to alter would be the Mueller tube voltage, it`s rated at 600vdc I may be alter that without much difficulty, but I don`t want to shorten the life of the tube.

[Guest pariahsfn]

I have had and destroyed two such counters, Velleman kits both.

 

I think what destroyed them under the same circumstances you describe,

inducing currents which I surmise eroded the detection plates. (A guess at best)

 

After going through two of these units,

I was considering how to construct something a bit more robust,

perhaps some kind of home-built 'geiger-muller' tube replacement.

 

I wonder if (experiments suggest otherwise) it would be possible to make

a crude element using some type of thin film capacitor to do the trick,

the dielectric being some form of self-healing hydrocarbon.

 

Any thoughts on this?

[YT2095]

Thnx, Mines a velleman kit also, I`ll be sure not to overload it in the future, as the detector is almost as expensive as the entire kit when bought seperately.

 

before having this kit though, I did experiment with thermionic valves, pumping in a voltage just below breakdown with the cathode cold, and hoping a stray particle would ionise a path and cause a tiny spike. sadly I had no Ion source at that time and couldn`t test it. but if it`s of any use to you, start from that point, it MAY work?

[Guest pariahsfn]

I tried a basic capacitor as well as using various tubes like UV tubes

and dead incandescent bulbs,

but lacking a reliable emitter I could not see expected background noise.

 

currently am on some other experiments,

but I will revisit this soon.

 

I need a detector - I know I have soft xrays from some of my work,

and according to material from otheres I should be having some

strong xrays as well as alphas (which would be a bit harder to detect)

[I_DONT_CARE]

I was thinking of geting a geiger counter but i dont know what to get. the Inspector EXP Seems good anyway i want the geiger counter to find uranium so it needs to be very Sensitive

[Thomas Kirby]

I bought a Geiger Counter a few years ago' date=' It was a kit costing about £70.

I`ve had it tested by a friend of mine at Birmingham Uni, and she wrote a rough list of test results, It`s almost deaf at Alpha radiation, better response at Beta and works just fine at Gamma.

that being said, I was wondering WHY it goes absolutely balistic when I put it near my plasma ball or my Tesla Feild generator?

I`ll get counts from over 3 feet away!

anyone have any ideas what may cause this?[/quote']

 

The Geiger-Muller tube works by maintaining electrical charges in its anode and cathode. Different tubes may run from 300-1500 volts. Radiation ionizes gas inside creating a conductive path. This makes the "click" you hear. Being near the Tesla coil increases the charge on the tube, making it more sensitive. It also simply knocks electrons from the tube itself. The counter goes wild for the same reason that fluorescent tubes light up near the coil.

[YT2095]

Nice answer!

 

this counter of mine works at 600Volts dc (low current), I`ve heard that Over charging them can damage them also, so is it possible that the effect this has when around such a field may damage it eventualy?

[Thomas Kirby]

Nice answer!

 

this counter of mine works at 600Volts dc (low current)' date=' I`ve heard that Over charging them can damage them also, so is it possible that the effect this has when around such a field may damage it eventualy?[/quote']

 

Yes, definitely. The field can induce extremely high voltages in anything nearby. The electrodes can pit and eventually fail if they are hit with enough arcs, especially the one that's like a wire through the center. The sensing electronics are much more vulnerable. The charge from the Tesla coil can jump right across the high voltage capacitor between the tube and the amplifier. It can even fry the high voltage supply.

 

The Velleman kit has the tube right on the circuit board. I just looked it up. All of your electronics gets as close to anything you measure with it as the tube does. The high voltage supply has semiconductors on the high side, too. It uses a chain of diodes and capacitors to multiply the voltage from the transformer. I can't seem to download a manual for it.

 

There has to be a little bit of gas in the tube for it to work. It's more sensitive to lower energies if that gas is under low pressure. Neon, argon, and krypton are good. If you wanted to improvise a tube again, that's the way to go.

 

You won't have any luck measuring alpha unless you find a tube with an alpha window. Then you have to take very good care of it because that's an extremely thin sheet of mica between your tube and the radiation source. The window has to face that source and you have to be very close to it.

[Douglas]

I bought a Geiger Counter a few years ago' date=' It was a kit costing about £70.

I`ve had it tested by a friend of mine at Birmingham Uni, and she wrote a rough list of test results, It`s almost deaf at Alpha radiation, better response at Beta and works just fine at Gamma.

that being said, I was wondering WHY it goes absolutely balistic when I put it near my plasma ball or my Tesla Feild generator?

I`ll get counts from over 3 feet away!

anyone have any ideas what may cause this?[/quote']If your plasma ball and tesla generator are generating impulses, they create an infinite spectrum.

[christo]

It is radon which is attracted to the high electric field. This deposits radon daughters and that is where the ballistic radiation is from. You can do the same trick with an air ionizer. If you use one with a filter, the radon builds up on the filter. Lots of beta and alpha and gamma.

Chris

[christo]

I think it is radon which builds up on the surface of any highly charged body due to polarisibility effects. This also happens near high voltage power lines. You can do the same trick with an air ioniser: high count rate from the radon and radon daughters.

Chris

[Pleiades]

I have a plasma ball and I noticed when I put my digital watch next to it the watch goes nuts, the alarm goes off sporadically, the numbers on the screen become nonsense and the watch refuses to work until I power cycle it by removing the battery.

 

As has been said before, the microwave radiation also will ionize the gasses in the Geiger counter and make it show a reading, just like a fluorescent tube will light up in a microwave oven.

 

I assume my watch went nuts because the plasma ball puts out so much stray electromagnetic radiation (probably in the microwave and radio bands) that it induces currents in the circuitry and makes it do weird things.

 

The Geiger counter could be going nuts for either reason, or both.

 

Edit: I highly doubt the plasma ball would give off x-rays. See: http://van.hep.uiuc.edu/van/qa/section/Electricity_and_Magnets/Stuff_that_Sparks/20040229205522.htm