Detecting Alpha Radiation

  • #1

Main Question or Discussion Point

Can we use Gold Leaf Electroscope to check whether a radioactive material gives off Alpha particles?
 

Answers and Replies

  • #2
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That is not the main use of an electroscope; electroscopes are used to determine if an object is charged. Alpha radiation may ionize the air and thus activate an electroscope. However, the alpha particles would have to penetrate the glass surrounding the gold leaf. See these articles:

https://en.wikipedia.org/wiki/Electroscope#Gold-leaf_electroscope

https://www.google.com/search?source=hp&ei=x2IMW5KMFoeI8APNgp2YBA&q=electroscope+radiation+detector&oq=electroscope+rad&gs_l=psy-ab.1.0.0l2j0i22i30k1l6.1424.7694.0.10630.17.16.0.0.0.0.220.2112.0j15j1.16.0....0...1.1.64.psy-ab..1.16.2110.0..35i39k1j0i131k1j0i67k1j0i20i264k1j0i131i67k1j0i22i10i30k1.0.nVM9c6_IiXA
 
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  • #4
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Can we use Gold Leaf Electroscope to check whether a radioactive material gives off Alpha particles?
I did this experiment when I was a kid--but not quantitatively. Two gold leaf electroscopes were charged together, then separated. One served as the control: it was placed in proximity to an ordinary needle. The other was placed in proximity to a needle tipped with polonium-210, an alpha emitter. The gold leaves came together much more quickly than on the control. I think I bought it as a science kit (!).

If you have a fresh, calibrated source and can weigh yours samples accurately, it might not be too difficult to get a quantitative answer.

Another simple way might be to place the sample close to luminescent screen, say zinc sulphide, in total darkless, and observe (or measure) the luminosity. That worked too, but I didn't measure it. The zinc sulphide was on one end of cork, and the needle with the emitter was stuck in the center.

BTW, brushes incorporating a Polonium-210 source used to be used to eliminate static from camera lenses, photographic negatives and even phonograph records. They worked great!
https://www.orau.org/PTP/collection/consumer products/staticeliminator.htm
 
  • #5
Hi, I was wondering what how sensitive your avarage geiger counter (GQ gmc-320 plus) would be to alpha particles? If there was only an extremely tiny amount of alpha emmiters would the cpm increase significantly or could it still be hovering around background radiation because of the small amount?
 
  • #6
Vanadium 50
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What does the sensor of the GQ gmc-320 plus look like? If it doesn't have a thin window (so thin you would break it if touched), it's not going to be sensitive to alphas.
 
  • #7
Thanks so much for you reply! No, it doesn't seem to so I'm guessing it's just for gamma and beta, would there be an increase in gamma and beta if alpha was present or would that be so small it would hardly push the cpm up?
 
  • #8
sophiecentaur
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That is not the main use of an electroscope;
What has that got to do with whether or not it can be used for that purpose? The discharge of a gold leaf is affected by ionising radiation so why not use it as a detector?
The rate of discharge could be measured at various distances and with various materials in between to compensate for the effects of Beta and Gamma. Having said that, there are better ways of detecting alphas but, if all you have is an electroscope, why not?
 

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