3 Production of X-rays

Question 1

what is a photon?

Answer 1

a wave packet equivalent to one quantum of energy

Question 2

what makes up an x-ray

Answer 2

millions of photons of different energies

Question 3

the diagnostic x-ray beam can vary in what factors (+brief defintion)

Answer 3

intensity - the number/quality of x-ray photons in the beam
quality - the energy is carried by the x-ray photons which is a measure of their penetrating power

Question 4

what factors can affect the intensity and/or the quality of the beam?

Answer 4

• size of tube voltage
• size of the tube current
• distance from the target
• time = length of exposure
• filtration
• target material
• tube voltage waveform

Question 5

in free space, how do x-rays travel?

Answer 5

in a straight line

Question 6

true or false: longer wavelength x-rays possess less energy and have little penetrating power?

Answer 6

true

Question 7

how can x-rays be dangerous to living tissue?

Answer 7

x-rays are capable of producing ionisation (ionising radiation) which can cause biological damage to living tissue

Question 8

what are the 4 possible fates when x-rays strike matter (patient tissues)?

Answer 8

• completely scattered with no loss of energy
• absorbed with total loss of energy
• scattered with some absorption and loss of energy
• transmitted uncharged

Question 9

what is thee defintion of attenuation?

Answer 9

reduction in the intensity of the main x-ray beam caused by absorption and scattering

Question 10

what is ionization?

Answer 10

removal of an electron from a neutral atom producing a negative ion (the electron) and a positive ion (the remaining atom)

Question 11

what is the radiation dose?

Answer 11

the amount of radiation absorbed by the patient
- low energy photons are often absorbed by soft tissue