X-ray/Photon Production

Question 1

potential energy

Answer 1

energy at rest

Question 2

What contains potential energy?

Answer 2

a focused electron cloud

Question 3

kinetic energy

Answer 3

energy in motion

Question 4

What contains kinetic energy?

Answer 4

an incident electron moving towards the anode

Question 5

What happens when electrons hit the atoms of the target?

Answer 5

they transfer their kinetic energy to the atoms

Question 6

What percentage of the kinetic energy of the incoming electrons crashing into the target is converted to HEAT?

Answer 6

99.8%

Question 7

What percentage of the kinetic energy of the incoming electrons crashing into the target is converted to useful X-RAYS?

Answer 7

less than 1%

Question 8

What is the distance between the filament and the x-ray tube target?

Answer 8

1 cm

Question 9

kVp (kilovolt peak)

Answer 9

the measure of the maximum electrical potential across an x-ray tube

Question 10

What else can kVp also be called?

Answer 10

Potential difference (PD)
Electromotive Force (EMF)
or Voltage (V)

Question 11

electromotive force

Answer 11

another term for kVp

Question 12

Most radiographs are produced with ____ to _____ kVp techniques

Answer 12

50 to 120

Question 13

1 kVp = _______ Volts

Answer 13

1,000

Question 14

higher kVp causes more electrons to be attracted to the anode target which does what?

Answer 14

increases the quantity of x-rays in the beam

Question 15

the higher the kVp, the greater the _________ ________ of __________ in the space charge

Answer 15

kinetic energy; electrons

Question 16

saturation current occurs:

Answer 16

when all possible electrons are attracted over to the anode target

Question 17

kVp influences…

Answer 17

quantity of x-ray beam

Question 18

beam intensity

Answer 18

quantity of the beam

Question 19

quality of beam:

Answer 19

how much kinetic energy the electrons will possess while traveling to the target

Question 20

quantity of beam:

Answer 20

amount of electrons travelling to the target

Question 21

more efficient x-ray photon production occurs because of:

Answer 21

a higher kVp

Question 22

Does tube current have an effect on the efficiency of photon production?

Answer 22

NO

Question 23

keV

Answer 23

kilo-electron Volt

Question 24

What does eV describe?

Answer 24

the kinetic energy of the electrons in the x-ray tube and the photons produced at the anode target

Question 25

velocity

Answer 25

how fast an object is traveling

Question 26

How fast do electrons travel from cathode to anode?

Answer 26

approx. half the speed of light

Question 27

Photons travel at the speed of light or they do not exist.

Answer 27

true

Question 28

tube voltage is expressed in what?

Answer 28

kVp

Question 29

tube current is expressed in what?

Answer 29

mA

Question 30

tube current

Answer 30

rate of electron flow crossing from cathode to anode

Question 31

tube current is determined by the number of electrons emitted by the filament during ____________ __________.

Answer 31

thermionic emission

Question 32

electrons are ___________ as they interact with anode target

Answer 32

slowed down

Question 33

What is produced as a result of deceleration of electrons?

Answer 33

x-ray photon

Question 34

What type of x-ray photon is produced by electron deceleration?

Answer 34

Bremsstrahlung

Question 35

What happens during electron ionization?

Answer 35

incident electron ionizes an atom of the target material

Question 36

ionization

Answer 36

the addition or removal of an electron

Question 37

What is produced as a result of electron ionization?

Answer 37

x-ray photon

Question 38

What type x-ray photon is produced during electron ionization?

Answer 38

Characteristic x-ray

Question 39

How can the technologist decrease the intensity of the x-ray beam while maintaining the same beam energy?

Answer 39

decrease milliamperage (mA)

Question 40

What 3 factors are required for x-ray production?

Answer 40

source of electrons means of rapidly accelerating electrons means of rapidly decelerating electrons

Question 41

During an attempted x-ray exposure, the x-ray tube fails to create any x-ray photons. Which of the following conditions is most likely to explain this failure? A. inadequate mA setting B. excessive kVp setting C. breakage of the cathode filament D. improper warm-up sequence

Answer 41

C. breakage of the cathode filament

Question 42

An exposure of an obese patient results in inadequate exposure. What should be modified to increase the energy and penetrability of the x-ray beam?

Answer 42

kVp

Question 43

An exposure taken with an 80 kVp would have an x-ray energy spectrum with a maximum photon energy of:

Answer 43

80 keV

Question 44

What factor is primarily responsible for controlling the energy of the x-ray beam?

Answer 44

kVp

Question 45

What condition is required to induce thermionic emission within the cathode filament?

Answer 45

high current

Question 46

Which component of the x-ray tube serves as the source of free electrons?

Answer 46

cathode filament