X-ray Production Vocabulary Flashcards

A complete set of vocabulary flashcards covering concepts from Chapter 6: X-ray Production.

Excitation

The process in an anode target where filament electrons transfer kinetic energy to outer-shell target electrons, raising them to a higher energy state without ionizing them, with excess energy given off as heat (infrared radiation).

Characteristic Interaction

An anode target interaction where a filament electron strikes an orbital electron of a target atom and removes it from orbit because its kinetic energy is equal to or greater than the electron's binding energy.

Characteristic Cascade

The process of outer-shell electrons dropping down to fill inner-shell vacancies created during characteristic interactions.

Characteristic Photon

An x-ray photon emitted during a characteristic interaction with energy equal to the difference in binding energies between the electron shells involved.

Tungsten K-Shell Binding Energy

The binding energy holding K-shell electrons in orbit within a tungsten atom, equal to $69.5\,\text{keV}$.

Bremsstrahlung Interaction

An anode target interaction where a filament electron misses orbital electrons, passes close to the nucleus, and slows down and changes direction due to nuclear attraction, releasing lost kinetic energy as a brems photon.

Filtration

The use of a material, usually aluminum ($\text{Al}$) or aluminum equivalent, to absorb low-energy x-ray photons from the x-ray beam.

Inherent Filtration

Filtration built into the x-ray tube head assembly, with the target window acting as the primary contributor.

Added Filtration

Additional filtration placed between the target window and top of the collimator, typically $2.0\,\text{mm Al}$ in general radiography.

Total Filtration

The total combination of inherent filtration and added filtration in a tube head assembly.

Compensating Filter

A filter attached to the collimator or placed on/adjacent to the patient to adjust for variations in anatomical thickness or density, producing a more uniform exposure to the image receptor.

Beam Quantity

The total number of x-ray photons present in an x-ray beam, directly affecting patient radiation dose.

Inverse Square Law

A physical law stating that x-ray beam intensity is inversely proportional to the square of the distance, expressed as $\frac{I_1}{I_2} = \frac{d_2^2}{d_1^2}$.

Beam Quality

The penetrating power of the x-ray beam, determined primarily by $\text{kVp}$ and beam filtration.

Penetration

The passage of x-ray photons through patient tissue to reach the image receptor, creating dark areas on the radiograph.

Half-Value Layer (HVL)

The thickness of absorbing material required to reduce the energy or intensity of an x-ray beam to one-half of its original value, typically $3\text{ to }5\,\text{mm Al}$ for diagnostic beams.

Primary Beam

The x-ray beam upon exiting the collimator before it interacts with and exposes the patient.

Remnant Beam

The x-ray beam that remains after interacting with patient tissue and exits the patient to expose the image receptor.

Discrete Emission Spectrum

A graphic plot illustrating characteristic x-ray production, depicted as vertical bars at specific energy levels because photon energies are limited to exact values.

Continuous Emission Spectrum

A graphic plot illustrating bremsstrahlung x-ray production, forming a bell-shaped continuum across a broad range of photon energies.

X-ray Emission Spectrum

A graphic representation of the complete x-ray beam, combining continuous bremsstrahlung energy curves with discrete characteristic peaks plotted by photon energy ($\text{keV}$) versus quantity.

Effect of mA on Emission Spectrum

An increase in $\text{mA}$ increases the amplitude (height) of both continuous and discrete portions of the emission spectrum, increasing quantity while having no effect on beam quality.

Effect of kVp on Emission Spectrum

An increase in $\text{kVp}$ increases the amplitude of the emission spectrum and shifts the curve to the right, increasing both beam quantity and quality.

Effect of Tube Filtration on Emission Spectrum

An increase in tube filtration decreases overall photon quantity while increasing average beam quality, reducing lower-energy photons and shifting the peak rightward.

Target Material Atomic Number (Z Number)

A property of the anode target where higher atomic numbers ($Z$) result in increased x-ray photon quantity, higher average beam energy, and rightward displacement of the characteristic line.