Question

Which of the following pair of scattering is important for therapeutic purposes?

(a) Coherent and Pair Production

(b) Photoelectric and Disintegration

(c) Compton and Photoelectric

(d) Pair Production and Disintegration

This question was posed to me by my school principal while I was bunking the class.

I want to ask this question from Radiation Therapy in portion Radiation Therapy of Clinical Science

Answer 1

Right choice is (d) Pair Production and Disintegration

Explanation: In pair production, an incoming photon of 1.02 MeV reacts with the nucleus and disintegrates into a positron and negatron. Positron due to high energy and low mass gets repelled from the nucleus and on meeting an electron, annihilation takes place. In disintegration, a high energy photon is absorbed by the nucleus which makes it excited and radioactive. To become stable again, it emits various radiations. Since both these techniques emit a large variety of radiations, they are used to destroy the cancerous cells and thus used for therapeutic purposes.