Ch. 8 X-ray Production

Question 1

What is the primary difference between X-rays and gamma rays?

Answer 1

X-rays are man-made, while gamma rays are naturally occurring

This distinction is important in understanding the origins of these types of radiation.

Question 2

What are the three main components of an X-ray equipment system?

Answer 2

• Operating console
• High voltage generators
• X-ray tube

These components work together to produce X-rays.

Question 3

How far does the thermionic cloud travel from the cathode to the anode?

Answer 3

Approximately 2 cm (~1 in)

This distance is crucial for the kinetic energy of the electrons.

Question 4

What are incident electrons also referred to as?

Answer 4

Projectile electrons

This term describes the electrons moving from the cathode to the anode.

Question 5

What happens to the linear energy of incident electrons when they strike the anode?

Answer 5

It is converted to either heat or X-ray photons (99% / 1%)

Also known as a target interaction

Question 6

What controls the speed of electrons traveling from cathode to anode?

Answer 6

Kilovoltage peak (KVp)

The KVp setting affects the kinetic energy of the electrons.

Question 7

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

Answer 7

The greater the speed of the incident electrons, the higher the X-ray photon energy

Question 8

What is the relationship between the number of electrons burned off during thermionic emission and the number of X-ray photons produced?

Answer 8

The number of electrons is directly related to the number of X-ray photons

This means more electrons result in more X-ray production.

Question 9

What does mAs stand for in X-ray production?

Answer 9

Milliamperage seconds

This measurement controls the amount of current and time in the X-ray production process.

Question 10

What is the effect of heat produced during the interaction of incident electrons with tungsten?

Answer 10

99% of the kinetic energy is converted to heat

This heat is a byproduct of the interaction, with no ionization occurring.

Question 11

What causes heat to be released when incident electrons interact with tungsten atoms?

Answer 11

Excitation of outer shell electrons of tungsten atoms

This excitation causes the atoms to vibrate, releasing energy as heat.

Question 12

True or False: Ionization occurs in tungsten during the production of heat from incident electrons.

Answer 12

False

The process described does not involve ionization of the tungsten atoms.

Question 13

Name the two types of x-ray photons.

Answer 13

• Bremsstrahlung Interaction
• Characteristic Interaction

Question 14

What is the effect of the kVp on x-ray production?

Answer 14

The type of x-ray being created is dependent on the kVp that is used

Question 15

What does ‘Brems’ mean in the context of x-ray production?

Answer 15

‘Brems’ means braking or slowing

Question 16

Does Bremsstrahlung Interaction involve ionization of the tungsten atom?

Answer 16

No ionization of the tungsten atom occurs

Question 17

Describe the interaction during Bremsstrahlung.

Answer 17

The incident electron interacts with the force field of the nucleus of the atom

Question 18

What happens to the incident electron in Bremsstrahlung Interaction?

Answer 18

The incident electron is deflected from the nucleus, causing it to brake or slow down

Question 19

What is emitted as a result of energy loss in Bremsstrahlung Interaction?

Answer 19

An x-ray photon

Question 20

How is the energy of the x-ray photon determined?

Answer 20

The energy of the x-ray photon is determined by the kinetic energy of the incident electron

Question 21

What percentage of the primary beam is made up of Bremsstrahlung rays when using 80-100 KVp?

Answer 21

80-90% of the primary beam

Question 22

What happens to the x-ray photons created each time the incident electron interacts?

Answer 22

They create photons with less and less energy

Question 23

At what KVp level do Bremsstrahlung rays make up 100% of the beam?

Answer 23

At 68 kVp or lower

Question 24

Fill in the blank: The primary beam is __________ due to the varying energies of x-ray photons.

Answer 24

heterogeneous

Question 25

True or False: Bremsstrahlung Interaction can occur multiple times with the same incident electron.

Answer 25

True

Question 26

What occurs during characteristic interactions?

Answer 26

The incident electron interacts with a k-shell electron, knocking it out of orbit, resulting in ionization of the atom.

Question 27

What is the electron binding energy of the K-shell electron in a tungsten atom?

Answer 27

69.5 KeV

Question 28

What happens when an electron is removed from the K-shell?

Answer 28

A hole is created, making the atom very unstable.

Question 29

What process is termed characteristic cascading?

Answer 29

The process of outer shell electrons dropping down to fill the inner shell hole, creating an x-ray photon.

Question 30

What type of emissions are K-shell emissions?

Answer 30

X-rays that have diagnostic quality energy to contribute to the primary beam.

Question 31

Why is there a 2.5 mm Al equivalent tube filtration in equipment operating over 70 KVp?

Answer 31

To filter out low-energy emissions that would only cause biological harm.

Question 32

What is the effect of filtration on the intensity and energy of the beam?

Answer 32

Filtration decreases the intensity of the beam but increases the average energy of the beam.

Question 33

What does ‘hardens the beam’ mean?

Answer 33

It means making the beam stronger and of higher energy.

Question 34

What percentage of the primary beam is made up of characteristic rays when using 80-100 KVp?

Answer 34

10-20%

Question 35

What percentage of characteristic rays is present until 70 KVp is used?

Answer 35

0%

Question 36

What does KVp stand for in the context of radiography?

Answer 36

Kilovolt peak energy

Question 37

What does mAs represent in radiography?

Answer 37

The number of photons in the primary beam.

(The quantity of the primary beam)

Question 38

Fill in the blank: The characteristic interactions are influenced by the _______ of the incident electron.

Answer 38

[kinetic energy]