1. Ionising radiation put to use
18.1
Ionising radiation put to use

2. Modelling radioactive decay
18.1 Ionising radiation put to use

3. Modelling radioactive decay using dice
Now plot the data, adding a line of best fit following the plotted data. It should be an exponential decay plot.
We can use dice to model the decay of dice. Roll your dice and record the number of dice that have rolled a 6. Record this value in the table. Roll the remaining dice. Repeat.
Roll
Dice remaining 1 2 3 4 5 6 7 8 9 10
Dice remaining
Roll
What is the half-life of this sample of dice?
Show your calculation on the graph

4. Learning objectives
Ionising radiations have a wide range of uses, in medicine, technology and everyday life
Ionising radiations mainly interact with matter by ionising atoms. Alpha radiation is strongly ionising, beta and gamma less so
Alpha particles have a definite range in air. Beta particles have a variable range. Gamma radiation is attenuated exponentially in absorbing material with I = I0e-µx
The unit of absorbed dose is the gray Gy, the energy in joule absorbed per kilogram of material. The unit of dose equivelant is the sievert Sv, the absorbed dose is gray multiplied by numerical factors to allow for the different effects of different types of radiation and tissue
The concept of risk combines the probability of an event with the consequences of that event occuring: risk = probability x consequence

5. 18.1 Ionising radiation put to use
Ionising radiations have a wide range of uses, in medicine, technology and everyday life

6. Medical radiography

10. Nuclear power

11. Non destructive testing

12. Smoke detectors

13. Radioactive tracers

14. Sterile insect technique

17. 18.1 Ionising radiation put to use
Ionising radiations mainly interact with matter by ionising atoms. Alpha radiation is strongly ionising, beta and gamma less so

18. Radiation
Symbol
Mass
Charge
Description

19. Alpha α 4 +2 Helium nucleus Beta β 1/ 1836 -1 Electron Gamma γ
Radiation
Symbol
Mass
Charge
Description
Alpha α 4 +2
Helium nucleus
Beta β 1/
1836 -1
Electron
Gamma γ
High energy photon

23. 18.1 Ionising radiation put to use
Alpha particles have a definite range in air. Beta particles have a variable range. Gamma radiation is attenuated exponentially in absorbing material with I = I0e-µx

25. 18.1 Ionising radiation put to use
The unit of absorbed dose is the gray Gy, the energy in joule absorbed per kilogram of material. The unit of dose equivelant is the sievert Sv, the absorbed dose is gray multiplied by numerical factors to allow for the different effects of different types of radiation and tissue

26. The gray (Gy)
One gray is the absorption of one joule of energy, in the form of ionising radiation, by one kilogram of matter. It reflects the physical effects of radiation.

27. Remember…
Energy
Force

28. The sievert (Sv)
The sievert is the SI derived unit of dose equivalent. It attempts to reflect the biological effects of radiation. The equivalent dose to a tissue is found by multiplying the absorbed dose, in gray, by a dimensionless "quality factor" Q, dependent upon radiation type, and by another dimensionless factor N, dependent on all other factors.

29. 18.1 Ionising radiation put to use
The concept of risk combines the probability of an event with the consequences of that event occuring: risk = probability x consequence

31. What kills more people each year?
Sharks, Flu, MRSA, Cold, Heat, Lightning, Fireworks 31

34. Dangers of drinking water