Medical Physics - Haidar Mahmoud Hassan.pdf

Medical physics radiocarivity

1. Radioactivity
University of Baghdad
College of Medicine
Haidar Mahmoud Hassan
M.Sc. Medical Physic

2. ✓what radioactivity is.
✓types of radiation.
✓Sources of Radioactivity
✓Hazards
✓how to prevent them.
Lecture objectives

3. Radioactivity is the process by which unstable
atomic nuclei release energy in the form of
radiation. This occurs spontaneously as atoms
decay into more stable forms.
Radioactivity

4. Sources of Radioactivity
1.Natural Sources: These include cosmic rays from space,
radon gas from the earth, and naturally occurring
radioactive elements like uranium and thorium.
2.Artificial Sources: These come from human-made sources
like nuclear reactors, medical devices (e.g., X-rays), and
certain industrial applications

5. Alpha α
Beta β
Gamma γ
➢A helium nucleus, consisting of
two protons and two neutrons.
➢A relative charge of +2.
➢A high mass compared with
beta particles.
➢Speed up to 0.1 x speed of
light
➢Strong ionizing effect
➢Not very penetrating (stopped
by paper, or skin, or a few
centimetres of air
➢Deflected by magnetic and
electric fields
The three types of radiation

6. Alpha α
Beta β
Gamma γ
➢Each beta particle is an
electron.
➢A relative charge of -1.
➢A low mass compared with
alpha particles.
➢Speed up to 0.9 x speed of light
➢Weak ionizing effect.
➢Penetrating, but stopped by a few
millimetres of aluminium or other
metal.
➢Deflected by magnetic and electric
fields
The three types of radiation

7. Alpha α
Beta β
Gamma γ
➢Not particles, but
electromagnetic waves and part
of the electromagnetic
spectrum.
➢No charge.
➢No mass
➢Travel at the speed of light
➢Very weak ionising effect.
➢Very strongly penetrating –
intensity reduced by lead and
thick concrete, but never
completely stopped.
➢Not deflected by magnetic or
electric fields
The three types of radiation

8. 1.Cell damage: Ionizing radiation can damage or kill cells,
leading to mutations, cancers, or other health issues.
2.Radiation sickness: High doses of radiation in a short
period can cause symptoms like nausea, fatigue, hair loss,
and, in extreme cases, death.
3.Long-term effects: Prolonged exposure can increase the
risk of cancers, genetic mutations, and organ damage
Hazards

9. 1.Minimize the time you spend near radioactive sources to
reduce exposure.
2.Increase your distance from radioactive materials or
radiation sources, as intensity decreases with distance.
3.Use appropriate materials (such as lead for X-rays or
gamma rays) to prevent radiation exposure.
4.Wear personal protective equipment, such as radiation
suits, gloves, and dosimeters, to monitor exposure.
Radiation Protection

10. 1.Jorgensen, J. and Hansen, L. (2012). Radiation and Nuclear Medicine. Springer.
2.Krane, K. S. (2017). Introductory Nuclear Physics. John Wiley & Sons.
3.Harris, S. and Lee, W. (2014). Radiation Protection and Dosimetry:
An Introduction to Health Physics. CRC Press.
References

11. Thank
you For
listening