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Question 1

Heart of Xray Machines

Answer 1

Xray Tube

Question 2

A special type of diode

Answer 2

Xray Tube

Question 3

electronic component that has 2 electrodes

Answer 3

Diode

Question 4

Converts electrical energy to electromagnetic energy

Answer 4

Xray Tube

Question 5

Components

Answer 5

Cathode Assembly
Anode Assembly
Glass/ Metal Enclosure
Glass Housing

Question 6

negatively charged electrode

Answer 6

Cathode

Question 7

Small coil of wire made of thoriated tungsten

Answer 7

Filament

Question 8

Filament Measurement

Answer 8

2mm wide, 1 or 2cm long

Question 9

Process where a heated material ejects electrons

Answer 9

Thermionic Emission

Question 10

most common cause of tube failure

Answer 10

Tungsten Vaporization

Question 11

enhances efficiency of thermionic emission

Answer 11

1-2% Thorium

Question 12

• metal shroud that surrounds the filament.
• negatively charged to electrostatically confine the electron beam to a small area
• designed to concentrate and direct electrons on a single narrow path toward the target.
• it serves as a grid or exposure switch in a grid- controlled x-ray tube
  -adjacent to the filament

Answer 12

Focusing Cup

Question 13

Factors that affect the focusing cups efficiency

Answer 13

1. size and shape
2. Charge
3. Filament size and shape
4. Position of the filament

Question 14

Dense cloud of electrons that force near the filament

Answer 14

Space Charge

Question 15

phenomenon that makes it harder for the filament to emit more electrons limiting the electron flow

Answer 15

Space charge effect

Question 16

the force that pushes object with the same electric charge, pushes each other because like charges repel

Answer 16

Electrostatic Repulsion

Question 17

• positively charged electrode
• conducts electricity, radiates heat and contains the target

Answer 17

Anode Assembly

Question 18

2 types of anode assembly:

Answer 18

Stationary n Rotating

Question 19

3 main functions of anode

Answer 19

1. Electrical Conductor
2. Support for the target
3. Thermal/ Heat Dissipator

Question 20

Common materials used in anode assembly

Answer 20

Copper 29
Molybdenum 42
Graphite

Question 21

Target is fixed. It is used when high tube current and power are not required

Answer 21

Stationary Anode

Question 22

Rotating Anode

Answer 22

• allows electron beam to interact with a larger target area
• used in general radiography

Question 23

roating anode rotates at about

Answer 23

3600-10000rpm

Question 24

• Shaft between anode and rotor
• Composition Mo

Answer 24

Anode Stem

Question 25

The area of the cathode that heats and produces x-ray

Answer 25

Target

Question 26

Tungsten preferred target material

Answer 26

1. High Atomic No. 2. Thermal Conductivity 3. High Melting Point

Question 27

gives enhanced mechanical strength- mechanical stress caused by high speed rotation, and also reduces brittleness

Answer 27

Tungsten with Rhenium

Question 28

Mammographic targets

Answer 28

Mo z=42 and Rh z=45

Question 29

- the actual Xray source - where the xrays are produced/ emitted - A region among the anode target where the accelerated electrons from the cathode bombard or strike

Answer 29

Focal Spot

Question 30

Helps improve sharpness and clarity of the images High resolution magnification radiography and mammography

Answer 30

Round Focal Spot

Question 31

Associated with small filament. Used when high detail and clarity are needed.

Answer 31

Small Focal Spot

Question 32

associated with large filament used when imaging larger body parts as it can handle higher amounts of energy

Answer 32

Large Focal Spot

Question 33

- is used to rotate the anode in an xray tube

Answer 33

Electromagnetic Induction Motor

Question 34

located outside the enclosure- stationary coil windings contain electromagnets Consists of series of electromagnets arranged evenly

Answer 34

Stator

Question 35

inside the glass enclosure Composition: copper and soft iron bars fused together into a single ??

Answer 35

Rotor

Question 36

External components

Answer 36

Support structures, protective housing, glass and metal enclosure

Question 37

made of Pyrex or borosilicate glass able to withstand the tremendous heat generated.

Answer 37

Glass Enclosure

Question 38

the natural capacity of the glass to filter or to block some of the low energy xrays

Answer 38

Inherent Filtration

Question 39

a segment of glass that is thinner than the rest

Answer 39

Tube Window

Question 40

- helps keep electric potential between the electrons of the tube current and the enclosure - Advantage: less likely to fail and has longer tube life

Answer 40

Metal Enclosure

Question 41

insulator protective housing that prevents electric shock

Answer 41

Diala Oil

Question 42

- protect it from damage from rough handling - is usually the one being handled

Answer 42

Protective Housing