X- ray production

Question 1

what are the two ways of producing x-rays?

Answer 1

1. a high speed electron changing direction suddenly, emitting a photon
2. electron may undergo a transition from a high energy to a low energy level

Question 2

what does electron interaction depend on?

Answer 2

strength of the electrical field
how close it is to the nucleus

Question 3

what happens if all KE is consumed?

Answer 3

electron is brought to a stop

Question 4

what is a heterogenous beam?

Answer 4

it is a beam which has a range of different energies

Question 5

what spectrum has a range of different x-ray energies

Answer 5

continuous spectrum

Question 6

what is the peak energy level

Answer 6

120 kv

Question 7

what spectrum is characteristic radiation

Answer 7

line spectrum

Question 8

what is characteristic radiation?

Answer 8

it is when an electron interacts with the inner shell (K), within the target material atom. enough energy is transferred to eject it, ionising it. Creating a vacancy within the k shell. KE of the incident electron must be equal to the IE of the target electron to overcome the BE

Question 9

what is the tungsten IE

Answer 9

69.5 KeV

Question 10

within CR what happens once the target atom is ionised?

Answer 10

electrons must adjust their levels, an upper shell electron moves into the space, this transition involves a release of energy as the inner shell represents a lower energy state. Energy is either released by transferring energy to an AUGER electron or by photon emission

Question 11

when is a photon emitted?

Answer 11

when the energy is equal to the difference between the energy levels involved in the transition. The precise energy is dependent on the particular energy level involved by the proton number

Question 12

what happens if the electron is further away from the nucleus?

Answer 12

less energy is needed as it is not affected by the positive nucleus change in direction which emits the photon

Question 13

what is the proportion of energy produced in bremsstrahlung

Answer 13

99% heat 1% x-rays

Question 14

what does a moving charge result in

Answer 14

moving electrons

Question 15

what is EM radiation

Answer 15

it is a disturbance of electrical filed by charges when they decelerate, accelerate or change direction. This radiation always moves outwards from the disturbance

Question 16

what spectrum is bremsstrahlung

Answer 16

a continuous spectrum

Question 17

what energy x-rays are important

Answer 17

high energy

Question 18

what is bremsstrahlung most effective for

Answer 18

high atomic atoms

Question 19

what produces a heterogeneous beam?

Answer 19

bremsstrahlung - acceleration of electrons at the target producing a range of x-ray energies

Question 20

describe bremsstrahlung

Answer 20

when high energy electrons enter the target and pass close enough to the nucleus, to be influenced by the electrical field around the nucleus. The electron experiences an electrical force of attraction to the positive nucleus making it deviate towards the nucleus. The sudden change in motion causes an acceleration which disrupts the EM field, and a photon of x rays is produced. The disturbance to the field and sudden direction change causes a deceleration as it swings around the nucleus with some KE being lost. The electron now travels at a slower rate, which is accompanied by an emission of an x-ray photon

Question 21

how do you calculate final KE of an electron

Answer 21

initial KE - photon energy