The Earth itself is a source of terrestrial radiation. Radioactive materials including uranium, thorium, and radium exist naturally in soil and rock. Essentially all air contains radon<span> , which is responsible for most of the dose that Americans receive each year from natural background sources.</span>
Answer:
In pair production, after the loss of Kinetic energy, the angular separation between the two photons is 180°.
Explanation:
- Pair production is the process of formation of two electrons, one negative and the other positive (positron), from a pulse of electromagnetic energy traveling through matter.
- It is a process of direct conversion of radiant energy to matter.
- The sum of the Kinetic energies of the formed particles amounts to a value of 4 MeV.
- When the kinetic energy is lost, emission of two photons, each with an energy of approximately 1 MeV in the form of gamma rays takes place ( in opposite direction).
Therefore, the angle of separation between the two photons is 180°.
Learn more about electromagnetic energy here:
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