“Strontium-90 is a pure beta source.” How could a physicist test this statement?

Question

I am stuck on this one, but I was thinking through measurement of radioactivity.

Answer 1

A physicist could test this statement by doing the following experiments:

1. Beta particle detection: Use a radiation detector or a Geiger-Muller counter specifically designed to detect beta particles. By placing the detector near a sample of Strontium-90, the physicist would observe an increase in the detection rate of beta particles, confirming the presence of beta radiation.

2. Absorption test: Beta particles can be stopped or absorbed by various materials such as aluminum or plastic. Place a thin sheet of aluminum or plastic between the Strontium-90 source and the detector. If the detection rate decreases significantly after putting the absorber material, this suggests that the primary radiation is indeed beta particles.

3. Absence of other radiations: To confirm that Strontium-90 is a pure beta source, the physicist should also show that there are no significant amounts of alpha or gamma radiation being emitted. Use an alpha and gamma radiation detector or a scintillation counter to verify the absence of these types of radiation from the Strontium-90 source. If no counts or insignificant counts of alpha and gamma radiation are observed, this would further support the claim that Strontium-90 is a pure beta source.

4. Energy spectrum analysis: A physicist could use a beta spectrometer to analyze the energy distribution of the beta particles emitted by Strontium-90. The energy spectrum should match the known decay scheme and the specific energies associated with the beta decay of Strontium-90. This could provide further evidence that Strontium-90 is a pure beta source.