Topic 7 - Uses of Nuclear Radiation

Question 1

what can both beta and gamma radiation be used for?

Answer 1

medical tracers

Question 2

how do beta/gamma radiation work as medical tracers?

Answer 2

1. a source emitting beta/gamma radiation is injected into the patient. the radiation penetrates the body tissues and can be detected externally
2. this is used to check if organs are working correctly

Question 3

what do sources of beta/gamma radiation need to be used for medical tracers?

Answer 3

short half-lives so initial levels are high enough to be detected, but radioactivity inside the patient quickly disappears

Question 4

how are gamma rays used to treat cancer?

Answer 4

radiotherapy (high doses of gamma rays) kills the cancer cells and stops them from dividing

Question 5

what are gamma rays used for?

Answer 5

sterilising food and equipment

Question 6

what are gamma-emitting tracers used for?

Answer 6

detecting leaks in underground pipes

Question 7

how are gamma-emitting tracers used to detect leaks in underground pipes?

Answer 7

the source is allowed to flow through the pipe. if there’s a crack, a detector will show extra high radioactivity at that point

Question 8

what do gamma-emitting tracers need to detect leaks in underground pipes?

Answer 8

a short half-life so they dont cause a long term hazard

Question 9

what can beta radiation be used for?

Answer 9

thickness control

Question 10

how is beta radiation used for thickness control?

Answer 10

direct radiation through the product being made (e.g. paper) and put a detector on the other side. when the detected levels change, it means the paper is too thick/thin

Question 11

why does it need to be a beta source used for thickness control?

Answer 11

the paper partly blocks beta radiation, whereas for gamma/alpha, it would fully block/not at all

Question 12

why would an alpha source be useless as a medical tracer?

Answer 12

1. the body’s tissues would stop it
2. it would be harmful because its very ionising