Radiation and Radioactive Decay Lecture Notes

These flashcards cover key concepts related to radiation, radioactive decay, calculations for medical imaging, radiation damage, and units of measurement in the field.

Radioactive Isotopes

Atoms with unstable nuclei that decay, emitting particles and radiation.

Half-life (T½)

The time required for half of the radioactive sample to decay.

Decay constant (λ)

A probability factor used to describe the rate of decay of a radioactive isotope.

Activity (R)

The rate at which a sample of radioactive material decays, measured in Becquerels (Bq).

Becquerel (Bq)

The SI unit of radioactivity, equivalent to one decay per second.

Gray (Gy)

The SI unit of absorbed dose, equivalent to one joule of energy deposited per kilogram of matter.

Sievert (Sv)

The SI unit used to measure the biological effect of ionizing radiation.

Relative Biological Effectiveness (RBE)

A factor used to compare the biological effects of different types of radiation.

Alpha decay (α)

A type of radioactive decay where an alpha particle (2 protons, 2 neutrons) is emitted from the nucleus.

Beta decay (β)

A type of radioactive decay where a beta particle (electron or positron) is emitted.

Gamma decay (γ)

A type of radioactive decay involving the emission of gamma rays from an excited nucleus.

Medical Imaging

Use of radioactive isotopes, like Technetium-99, to visualize internal organs for diagnostic purposes.

Ionization

The process by which neutral atoms or molecules acquire a net electric charge by gaining or losing electrons.

Radiation Damage

Damage caused to biological tissues by exposure to ionizing radiation.

Curies (Ci)

A non-SI unit of radioactivity, where 1 Ci equals 37 billion decays per second.

Natural sources of radiation

Radiation emitted from naturally occurring isotopes like potassium-40 and from cosmic sources.

Artificial sources of radiation

Radiation generated from human-made processes such as medical imaging and nuclear energy.

Radiation therapy

Medical treatment involving the use of high-energy radiation to kill cancer cells.

Radiation Protection

Measures taken to protect people from harmful effects of ionizing radiation.