Principles-Production of X-rays

Production of X-rays

What type of radiation are X-rays?

a form of electromagnetic radiation

The electromagnetic spectrum includes X-rays with wavelengths between ….?

0.1 and 0.5 angstrom

What is the relationship between frequency and wavelength in electromagnetic waves?

Inversely proportional

What are the conditions required for X-ray production?

Source of electrons

Accelerate electrons

Decelerate electrons

Target

All X-ray production occurs in a

vacuum

Anode is made up of

tungsten

In X-ray production, energy corresponds to the…

quality of the beam

Approximately 99% of the kinetic energy of incident electrons is converted to heat during …

X-ray production

What is the relationship between X-ray energy and the kinetic energy of incident electrons?

Directly proportional

What are the steps involved in heat production during X-ray production?

Electrons interact with outer-shell electrons of target atoms

Outer-shell electrons are raised to an excited energy level

Electrons drop back to their normal state

Infrared radiation is emitted as heat

What are the two types of target interactions that produce X-ray photons?

Bremsstrahlung and Characteristic

Bremsstrahlung radiation occurs when an incident electron is slowed by the force field of the

nucleus

The energy of Bremsstrahlung radiation depends on the energy of the incident

electron

What does the term kVp stand for in X-ray production?

kilo Voltage Peak

The average beam energy in Bremsstrahlung radiation is 30-40% of the

kVp selected

What type of interaction is responsible for characteristic radiation?

Inner-shell electron ejection

The emitted radiation in characteristic interactions is specific to the target

element

The K-shell binding energy of tungsten is approximately

69.5 keV

What determines the energy of the characteristic X-ray photon emitted during electron transitions?

Difference in binding energies

A heterogeneous beam contains a broad spectrum of energies

Bremsstrahlung emission spectrum

Bremsstrahlung

Generated by incident electron being slowed by nucleus

Characteristic

Generated by electron transitions in inner shells

What is the tungsten binding energy?

69.5 keV

The average beam energy in X-ray production is 30-40% of the set …

kVp

What are the factors that affect the X-ray emission spectrum?

mA (mAs)

kVp

Filtration

Generator Type

What does mAs primarily affect in the X-ray beam?

Beam quantity

….determines the penetrability and quality of the X-ray beam.

The kVp

Higher filtration in X-ray production results in decreased beam 

quantity

What effect does increased generator efficiency have on the X-ray beam?

Increased photon energy

low frequency

long wavelength

High frequency

short wavelength

what percentage is used for the production of xrays?

1%

What is coming from the cathode and hitting the anode?

Incident electrons (xray photons)

higher speed means

higher energy quality

The difference in origins of a low energy bremsstrahlung xray and a maximum energy xray, is that the maximum energy is produced when the incident electron:

gets extremely close to the nucleus

What does the term heterogenous mean, as it relates to the xray beam?

contains a variety of energies (polyenergetic)

xray tube heat production is dependent on …

the kVp and mAs selected

Define characteristic cascade

inner k shell electron is ejected from its orbit, outer shell drops down

What is the minimum kVp that will produce characteristic xrays?

70 kVp

define kVp

determines the quality (energy) of beam, highest energy of beam

Describe the relationship between the kVp and the average energy of the primary beam photons

They are directly proportional; the average beam energy is 30-40% of the selected kVp. A higher kVp leads to higher average energy of the primary beam photons.

which type of xray production involves ejecting an inner shell electron?

characteristic

which type of xray production involves a cascade effect?

characteristic

what type of interaction is responsible for the majority of the xrays produced in diagnostic xray?

Brems 80-90%

When mA is increased, with other technical factors remaining the same, What part of the emission curve is affected? and is it directly or indirectly proportional

Amplitude (height) of the emission curve. An increase in mA increases the quantity of X-ray photons, thus increasing the amplitude of the curve. directly proportional

how is the emission spectrum affected when kVp is increased? list two changes in the appearance

shifts to the right, increases in amplitude

How is the average energy of the beam affected when kVp is increased?

increases

Brems radiation

loss of kinetic energy given off as xray photon

Energy of Brems Radiation

The energy of the incident electron

the charge of the nucleus

the proximity of the incident electron to the nucleus

Interactions farther from the nucleus

lower energy brems

interactions closer to the nucleus

higher energy brems

Tungsten electron Transition

The further out the electron comes to drop into vacancy, the greater the characteristic radiation produced, may be from any shell

where does the production happen?

within the tube

Higher filtration means

decreased in quantity