INTERNAL STRUCTURES (ANODE)

Question 1

It conducts electricity, radiates heat & contains the target

Answer 1

Anode

Question 2

3 functions of Anode

Answer 2

Electrical Conductor
Mechanical support for the target
Thermal dissipator

Question 3

3 most common Anode Material

Answer 3

Copper (Cu-29)
Molybdenum (Mo-42)
Graphite

Question 4

used in dental x-ray imaging systems, some portable imaging systems, and other special-purpose units in which high tube current and power are not required

Answer 4

Stationary Anode

Question 5

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

Answer 5

Target

Question 6

➢ It allows the electron beam to interact with a much larger target area
➢ 3,600 - 10,000 rpm
➢ target areas of typical stationary anode (4 mm2) and rotating anode (1800 mm2) x-ray tubes with 1-mm focal spots.

Answer 6

Rotating Anode

Question 7

The shaft between the anode & the rotor

Answer 7

Anode stem

Question 8

Composition of Anode Stem?

Answer 8

Molybdenum
Characteristics: poor heat conductor

Question 9

It is used to turn and power the anode

Answer 9

Electro Magnetic Induction Motor

Question 10

2 Principal parts of electromagnetic induction motor

Answer 10

Stator & Rotor

Question 11

Located outside the enclosure.
- Stationary coil windings (electromagnets)

Answer 11

Stator

Question 12

Located inside the glass envelope
- Rotating part (shaft)

Answer 12

Rotor

Question 13

Time it takes the rotor to rest after use
- Approximately 60 s

Answer 13

Coast time

Question 14

➢ Design incorporated into x-ray tube targets
➢ Allows large area for heating while maintaining a small focal spot

Answer 14

Line-Focus Principle

Question 15

the ability of the cone of x- rays produced to adequately cover the largest field size used

Answer 15

Limiting Factors

Question 16

The area projected onto the patient & image receptor.

Answer 16

Effective Focal Spot/Effective Target Area

Question 17

The area on the anode target that is exposed to electrons from the tube current

Answer 17

Actual Focal Spot

Question 18

One unfortunate consequence of the line-focus principle
➢One unfortunate consequence of the line-focus principle is that the radiation intensity on the cathode side of the x-ray field is greater than that on the anode side.

Answer 18

Anode Heel Effect

Question 19

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

Answer 19

Off –Focus Radiation/Extra-focal x-rays/Undesirable radiation

Question 20

it guides and aids the radiographer in using x-ray tubes and acceptable exposure levels to maximize x-ray tube life.

Answer 20

X-ray tube rating chart

Question 21

Three types of Rating Charts

Answer 21

1.Radiographic Rating Chart
2.Anode Cooling Chart
3.Housing Cooling Chart

Question 22

The most important as it conveys which radiographic techniques are safe and which techniques are unsafe for x-ray tube operation.

Answer 22

Radiographic rating chart

Question 23

It is used to determine the thermal capacity of an anode and its heat dissipation characteristics

Answer 23

Anode Cooling Chart

Question 24

➢It has the same use to anode cooling chart.
➢ Complete cooling of the housing is after a maximum heat capacity from 1 to 2 hours.

Answer 24

Housing Cooling Chart