Radiation production exam

Radiography

is the recording of images created by the use of x-ray energy.It is both an art and a science.

Physics

is a branch of physical science that studies matter and energy and their interrelationships.

❏ Repulsion-attraction

❏ Distribution

❏ Concentration

❏ Movement

❏ Inverse square law

Laws of Electrostatics

repulsion-attraction

refers to the fundamental forces that either push objects apart or pull them together

Distribution

refers to how a quantity such as mass, charge, or energy is spread out in space or within an object.

Concentration

refers to the amount of a substance (like particles or energy) present in a given volume or area.

Movement

Only negative charges move along solid conductors.

Inverse Square Law

• Refers to a physical quantity or intensity that is inversely proportional to the square of the distance from the source.

• The force between two charges is directly proportional to the product of their magnitudes and inversely proportional to the square of the distance between them.

X-ray Production

• Target Interaction

• Bremsstrahlung

• Characteristic

1895

Discovered in ____ by German physicist named Wilhelm Roentgen.

Wilhem Conrad Roentgen

who is the german physicist that discovered x-ray

invisible

X-rays are

speed of light in a vacuum

X-rays travel at

straight lines

X-rays travel in

electric and magnetic fields

They are unaffected by_____ They cannot be refracted

ionisation

Properties of x-ray cause ___

CATHODE

negative side of x-ray tube

Anode

positive side of x-ray tube

❏ Bremsstrahlung Interactions

❏ Characteristic Interactions

two types of target interactions

BREMSSTRAHLUNG INTERACTION

❏ Named by the German word for braking or slowing.

❏ The abbreviation “brems” is also used.

❏ Brems interactions may occur only when the incident electron interacts with the force field of the nucleus

100 kvp, 100 keV

Tube Maximum Potential __ kvp = Bremsstrahlung __ keV

CHARACTERISTICS INTERACTION

When the energy of an electron incident on the target exceeds the binding energy of an electron of a target atom, it is energetically possible for a collision interaction to eject the electron and ionize the atom.

TUNGSTEN-74

BINDING ENERGIES OF DIFFERENT SHELL ELECTRONS

70 KeV

K-

12 KeV

L-

2.8 KeV

M-

x-ray photons

When ____ are produced at the anode, they are emitted isotropically.

Anode Heel Effect

Reduction of the X-ray intensity at the anode side of an X-ray field

Common Terms Related to X-Ray Beam

Primary beam

Exit / Remnant beam

Leakage radiation

Before interacting photons.

Primary radiation

After at least one interaction

Scattered radiation

Not absorbed by the X-Ray tube housing shielding.

Leakage radiation

After passage through matter.

Remnant radiation

An often overlooked factor that can cause serious degradation of radiographic image quality is off-focus, or extrafocal, radiation.

Off-Focus Radiation