Radiation Physics & Radiobiology

These flashcards cover key vocabulary terms and concepts related to radiation physics and radiobiology, based on the lecture notes provided.

Electromagnetic Radiation

Wave-like fluctuations of electric and magnetic fields, examples include gamma rays, X-rays, visible light, microwaves, and radiowaves.

Electromagnetic Spectrum

The range of all types of electromagnetic radiation.

Frequency

The number of cycles per second, measured in Hertz.

Wavelength

The distance between two consecutive wave crests.

X-ray Tube

Device used to produce X-rays through the interaction of electrons with a target.

Bremsstrahlung Radiation

Radiation produced when a projectile electron is decelerated by the nucleus of a target atom.

Characteristic Radiation

X-rays emitted when an outer-shell electron fills a vacancy created by the ejection of an inner-shell electron.

Photoelectric Effect

Interaction where an incident X-ray interacts with an inner-shell electron, ejecting it and being absorbed.

Compton Effect

Interaction where an incident X-ray ejects an outer-shell electron, ionizing the atom and changing direction.

Linear Energy Transfer (LET)

Measure of the rate at which energy is transferred from ionizing radiation to tissue.

Relative Biological Effectiveness (RBE)

Ratio of the dose of standard radiation necessary to produce a given effect, compared to the dose of test radiation needed for the same effect.

Target Theory

Theory that suggests a cell will die if target molecules, specifically DNA, are inactivated by radiation exposure.

Radiolysis of Water

Separation of water into molecular products due to irradiation, resulting in free radicals.

Somatic Effects

Effects of radiation that occur in the exposed individual, including early and late effects.

Acute Radiation Syndrome (ARS)

Serious illness or death occurring due to whole-body doses of radiation of 1 Gy or more in a short period of time.

Oxygen Enhancement Ratio (OER)

A measure comparing the increased sensitivity of tissue to radiation when it is oxygenated versus when it is not.

Deterministic Effects

Radiation effects that have a threshold dose and occur shortly after high doses of radiation exposure.

Stochastic Effects

Radiation effects that occur without a threshold and may present years after low doses of radiation exposure.