Radiology M3 - R3: Production of X-rays

Question 1

the production of X-rays is dependant on three things, 1 of which is the production of electron. describe how these electrons are produced

Answer 1

current is passed through a tungsten element.

current caused the element to heat up causing the breaking off of electrons, this is called THERMOIONIC emmision

this process occurs in the cathode

Question 2

the production of X-rays is dependant on three things, 1 of which is the accelaration of electrons, how is this accomplished.

Answer 2

once the elctron have been produced through thermoionic emmision, they are negatively charged.

the electrons are then accelarated to the annode, this is done polar charges and the KpV

Question 3

the production of X-rays is dependant on three things, 1 of which is the deacclerating of the electrons, how does this happen

Answer 3

the accelrating electrons hit the annode, the sheer force produce here produces X-rays

Question 4

what would happen to the number of electrons and X-rays if the tube current was increased.

Answer 4

the increase in tube current would give more rise to electrons due to an increase in thermoionic emission - this then results in more X-rays

Question 5

when the electrons collide with the anode there are two types of X-ray spectrum

Answer 5

continous spectrum - this is known as breaking radiation and has a wide range of photon energies

characteristic spectrum - this spectrum is dependant on the material used in anode and dependant on which electron shell

Question 6

in which spectrum would you expect to find small deflections of photon enegy

Answer 6

continous spectrum

Question 7

X - ray defintion - random change in direction after hittin something

Answer 7

scattering

Question 8

X - ray defintion - deposition of energy in tissues

Answer 8

absorption

Question 9

X - ray defintion - number of x-ray photons in a defined area of the beam

Answer 9

intensity

Question 10

X - ray defintion - reduction in intensity of beam due to scattering and absorption

Answer 10

attenuation

Question 11

X - ray defintion - removal of electrons from natural atom to give - ve & + ve

Answer 11

ionisation

Question 12

X - ray defintion - the abilty of photons to pass through or into tissue/materials

Answer 12

penetration

Question 13

can X-rays be detected by human senses

Answer 13

no

Question 14

x-ray interations - if x-rays are absorbed do they lose or gain energy

Answer 14

lose energy

Question 15

x-ray interactions - if x-rays are completley scattered, do they have a loss of energy

Answer 15

no

Question 16

low energy photons are often absorbed by what

Answer 16

soft tissues

Question 17

what is the definition of : radiation dose

Answer 17

is the amount of radiation absorbed by the patient