X-ray Tube Ch 7

Question 1

It converts electrical energy to

electromagnetic energy

Answer 1

X-ray Tube

Question 2

Any tube with two electrodes

Answer 2

Diode

Question 3

External Structures if X-ray tube

Answer 3

Support Structure, Protective Housing &

Glass/Metal Enclosure

Question 4

It consists of two perpendicular sets of

ceiling-mounted rails

Answer 4

Ceiling-Support System

Question 5

When x-ray tube is centered above the

examination table at the standard SID

Answer 5

Preferred Detent Position

Question 6

It consists a single column with rollers at

each end

Answer 6

Floor-To-Ceiling Support System

Question 7

It provides for very flexible x-ray tube

positioning

Answer 7

C-Arm Support System

Question 8

Lead-lined metal container into which the xray tube is fitted

Answer 8

Protective Housing

Question 9

Emission with equal intensity in all

directions

Answer 9

Isotropic Emission

Question 10

A thin section of a glass/metal envelope

through which useful beam emerges

Answer 10

Window

Question 11

X-rays emitted through the window

Answer 11

Useful Beam/Primary Radiation

Question 12

X-rays that escape through protective

housing

Answer 12

Leakage Radiation

Question 13

It contains the x-ray tube & its components

Answer 13

Glass/Metal Enclosure

Question 14

Glass Enclosure

Answer 14

Pyrex glass
o Able to withstand tremendous heat
generated

Question 15

Maintain constant electric potential between
the electrons of the tube current & the
enclosure

Answer 15

Metal Enclosure

Question 16

The negative side of the x-ray tube

Answer 16

Cathode

Question 17

2 primary parts of Cathode

Answer 17

filament & focusing cup

Question 18

A coil of wire that emits electrons when it is

heated

Answer 18

Filament

Question 19

Metal shroud that surrounds the filament

Answer 19

Focusing Cup

Question 20

most common cause of tube failure

Answer 20

Tungsten vaporization with deposition on the

inside of the glass enclosure

Question 21

Cloud of electrons

Answer 21

Space Charge

Question 22

A phenomenon of the space charge that
makes it difficult for subsequent electrons to
be emitted by filament because of
electrostatic repulsion

Answer 22

Space Charge Effect

Question 23

The x-ray tube current is adjusted by

controlling…

Answer 23

the filament current

Question 24

Filament current that has risen to its
maximum value because all available
electrons have been used

Answer 24

Saturation Current

Question 25

A region of the anode target in which | electrons interact to produce x-rays, actual x-ray source

Answer 25

Focal Spot

Question 26

Important for high resolution magnification | radiography & mammography

Answer 26

Round Focal Spot

Question 27

It is used when small body parts are image | & when better spatial resolution is required

Answer 27

Small Focal Spot

Question 28

It is used when large body parts are imaged

Answer 28

Large Focal Spot

Question 29

The positive side of the x-ray tube

Answer 29

Anode

Question 30

3 Most Common Anode Materials

Answer 30

Copper (Cu-29), Molybdenum (Mo- | 42) & Graphite

Question 31

It is used when high tube current & power | are not required

Answer 31

Stationary Anode

Question 32

The area of the anode struck by the electrons | from the cathode

Answer 32

Target

Question 33

The material of choice for the target

Answer 33

Tungsten (Z=74)

Question 34

3 Main Reasons why Tungsten is the material of choice

Answer 34

High Atomic Number Thermal Conductivity High Melting Point

Question 35

It allows the electron beam to interact with a | much larger target area

Answer 35

Rotating Anode

Question 36

Higher tube currents and shorter exposure | times are possible with...

Answer 36

the rotating anode

Question 37

The shaft between the anode & the rotor

Answer 37

Anode Stem

Question 38

It is used to turn the anode

Answer 38

Electromagnetic Induction Motor

Question 39

2 principal parts of Electromagnetic Induction Motor

Answer 39

stator & rotor

Question 40

Located outside the enclosure

Answer 40

Stator

Question 41

Located inside the glass envelope

Answer 41

Rotor

Question 42

Time it takes the rotor to rest after use (60s)

Answer 42

Coast Time

Question 43

the ability of the cone of xrays produced to adequately cover the largest field size used

Answer 43

Line Focus Principle

Question 44

The area projected onto the patient & image | receptor

Answer 44

Effective Focal Spot/Effective Target Area

Question 45

Consequence of line focus principle

Answer 45

Anode Heel Effect

Question 46

The imaginary line generated by the | centermost x-ray in the beam

Answer 46

Central Ray

Question 47

X-rays produced in the anode but not at the | focal spot

Answer 47

Off-Focus Radiation/Extrafocal X-rays

Question 48

Three Ways of Heat Dissipation

Answer 48

Radiation, Conduction & Convection

Question 49

The transfer of heat by the emission of | infrared radiation

Answer 49

Radiation

Question 50

The transfer of energy from one area of an | object to another

Answer 50

Convection

Question 51

The transfer of heat by the movement of a | heated substance from one place to another

Answer 51

Convection

Question 52

It guides & aids the radiographer in using xray tubes & acceptable exposure levels to maximize x-ray tube life

Answer 52

X-ray Tube Rating Chart

Question 53

Three Types of Rating Charts

Answer 53

- Radiographic Rating Chart - Anode Cooling Chart - Housing Cooling Chart

Question 54

It conveys which radiographic techniques | are safe & unsafe for x-ray tube operation

Answer 54

Radiographic Rating Charts