Production Of Xrays

Question 1

What components make up the tube head?

Answer 1

Filament cathode ( tungsten) 
Copper block
Target anode ( tungsten) 
Step up transformer
Step down transformer
Leaded glass
Led shield
Oil
Aluminium filter

Question 2

What is the function of the cathode?

Answer 2

Provides source of electrons

Question 3

What is the function of the copper block?

Answer 3

Removes and dissipates heat

Question 4

What does the step up transformer do?

Answer 4

Send high kv across tube

Question 5

What does the step down transformer do?

Answer 5

Creates low filament milli amp

Question 6

What does the lead shield do?

Answer 6

Minimises radiation leakage

Question 7

What does the oil do?

Answer 7

Facilitates heat removal

Question 8

What does the aluminium filter do?

Answer 8

Removes low energy, damaging X-ray photons

Question 9

What are the two types of xray spectra?

Answer 9

Continuous spectrum ( bremsstraulung/ breaking radiation)
Characteristic spectrum

Question 10

What is meant by continuous spectrum?

Answer 10

X-ray photons emitted by rapid deceleration of bombarding electrons passing close to nucleus in tungsten atom

Question 11

What is meant by characteristic spectrum?

Answer 11

Depends on material used in anode

Emitted by loss of electrons from k and l shells

Question 12

What are the main properties of xrays?

Answer 12

Travel in straight lines
X-ray photons for divergent beam
Can travel through vacuum
Can be absorbed
Can be scattered

Question 13

What come under non ionising with regards to electro magnetic spectrum

Answer 13

Radio
Microwaves
Infrared
Low end ultra violet

Question 14

What come under ionising with regards to the electro magnetic spectrum

Answer 14

High end ultraviolet
Xrays
Gamma rays

Question 15

Define scattering

Answer 15

Random change in direction after hitting something

Question 16

Define absorption

Answer 16

Deposition of energy in tissues

Question 17

Define intensity

Answer 17

Number of X-ray photons in a defined area of a beam

Question 18

Define attenuation

Answer 18

Reduction in intensity of beam due to scattering and absorption

Question 19

Define ionisation

Answer 19

Removal of electrons from neutral atom to give negative electron and positive atom ions

Question 20

Define penetration

Answer 20

Ability of photons to pass through tissues/ materials

Question 21

What are the possible interactions of X-ray beams?

Answer 21

Completely scattered with no loss of energy
Absorbed with total loss of energy
Scattered with some absorption and loss of energy
Transmitted unchanged

Question 22

What are the possible interactions of xrays at atomic level

Answer 22

Rayleigh scattering- pure scatter
Photoelectric effect- pure absorption
Compton effect- absorption and scatter
Pair production - pure absorption

Question 23

What is the photoelectric effect?

Answer 23

Pure absorption predominating with low energy protons

Question 24

Describe the stages of photoelectric

Answer 24

Incoming xrays interact with k electrons
Electron ejected with much energy
X-ray photons looses all energy and disappears
Vacancy exists in inner shell and is filled by outer shell electrons
Excess energy emitted as light or low energy xrays
Atomic stability and neutral state

Question 25

What is the Compton effect?

Answer 25

Absorption and scattering process predominating with higher energy photons

Question 26

Describe the stages of Compton effect

Answer 26

Incoming xray photon interacts with outer shell electron
Electron injected with some energy from X-ray
Electron now called Compton recoil electron
Remaining photon energy scattered
Escapes from tissues into environment

Question 27

What are the main components of the tube head?

Answer 27

Tube head
Collimator
Positioning arms
Control panel
Circuitry