If a small sample of radioactive material is brought closer to Geiger counter. It detects alpha, beta and gamma radiations from the sample material. can someone tell me how the alpha radiation from the beam can be filtered without affecting the beta or gamma radiation?

Don't know if I added the right tags.

  • 1
    $\begingroup$ A great many Gieger counters are not significantly sensitive to alpha radiation. To get one that is you have to carefully engineer a very thin window. $\endgroup$ – dmckee May 25 at 4:53

Alpha particles produced during radioactive decay (a) are slow ($E\approx 5 \text{ MeV} \implies v \approx 0.05 c$) and (b) tend to ionize everything in their path, losing what energy they have fairly quickly. This means that they are very easy to stop.

If your source is more than a few centimeters from your detector, then the ambient air will screen most of them out. Otherwise, a sheet of paper between the source and detector should be enough to do the job.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.