Production of X-Rays

what factor affects the energy of the electrons in the x-ray tube

kVp

the primary beam of x-ray photons leaving the x-ray tube can be described as

heterogenous, polyenergetic beam

when electrons interact with outer shell electrons of the target atom, and no ionization occurs, thus resulting in

heat

which orbital shell of a tungsten atom will produce energies in the diagnostic range of x-ray

K shell

mAs determines what beam characteristic

quantity

what type of x-ray production interaction will occur if the x-ray tube voltage is set at 60 kVp

bremsstrahlung

a high speed electron entering the tungsten target is attracted to the positive nucleus of a tungsten atom and, in the process, is decelerated and changes direction. this results in the production of what type of radiation

bremsstrahlung radiation

what is the minimum kVp setting that will produce characteristic x-rays

70 kVp

an increase in which factor will increase the penetrating ability, or energy, of the beam

kilovoltage

when electrons strike the target of the x-ray tube, what percent of their kinetic energy is converted to x-rays

1%

what is the k-shell binding energy of tungsten

69.5 keV

the energy of a bremsstrahlung photon is equal to

difference between the entering and exiting kinetic energy of the incident electron

what technical factor has a directly proportional effect on the amplitude of the emission spectrum

mA (mAs)

characteristic x-rays are produced when

orbital electrons drop from an outer shell to fill an inner shell vacancy

the maximum x-ray energy for a given exposure will be equal to ____ selected by the technologist at the operator’s console

kVp

x-rays produced from the interaction of high-speed electrons and the target of the x-ray tube are characteristic of what material

tungsten

when electrons strike the anode of an x-ray tube, how much of their energy is converted to x-ray

1%

the transition of orbital electrons from outer to inner shells produces

characteristic radiation

the speed and energy of the electron stream as it passes across the x-ray tube is primarily controlled by the

selected kilovoltage

which of the following is true as generator efficiency improves

1. number of photons in the beam increases

2. the amplitude increases in the emission spectrum

3. the average energy is lower

1 and 2

within the diagnostic x-ray range, most x-ray photons are produced by ____ target interaction

bremsstrahlung

during the production of x-rays, an inner orbital electron is ejected from its shell. after an outer shell electron drops the fill the “hole”, another electron will drop to fill the “hole” it left, and so on. this process is called

characteristic cascade

thermionic emission affects the ____ of the photons in the x-ray beam

quantity

in the x-ray tube, electrons travel from _____ to _____

cathode to anode

this target interaction produces a wide variety of x-ray energies

bremsstrahlung

the average energy of the primary beam is

30-40% of the selected kVp

another name for heterogenous beam is

poly energetic beam

what happens to electrons that are ejected from a target atom

they move on to have additional (multiple) interactions or fill a vacancy in another atom

which factor affects both the quality and quantity of the beam, although quantity is not affected in a directly proportional matter

kVp

which factor affects the quantity of the beam in a directly proportional matter

mAs

interactions occurring with the L-P shells will not produce x-ray photons within the diagnostic range

true

which interaction produces a beam that is poly energetic

bremsstrahlung

the technologist selects 100 kVp at the operators console. calculate the avg energy of the beam

30-40%, 30-40 keV

characteristic x-rays are:

1. predictable

2. heterogenous

3. characteristic of the target material binding energies

4. unpredictable

5. energy levels can be calculating by subtracting the binding energies of the shells involved

6. interactions will produce a “cascade” effect

7. interaction occurs with outer shell electrons

1, 3, 5, 6

an incoming electron that is slowed / changes direction very close to the nucleus of the atom, will have

more energy than one that slows/changes direction farther from the nucleus

the energy of brems radiation depends on

1. the proximity of the incident electron to the nucleus

2. the difference in binding energies

3. the energy of the incident electron

1 and 3

true or false. the majority of the primary x-ray beam is made up of brems radiation

true

true or false. at 100 kVp, 10-20% of the beam is made up of characteristic radiation

true