Master the Line Focus Principle

X-ray Tube Focal Spot

• The focal spot refers to the area on the target surface struck by the electron stream.

Line Focus Principle

• The line focus principle involves angling the target to focus the electron beam into a smaller area, increasing x-ray intensity.

Focal Spot Size

• The small focal spot in most x-ray tubes used today is around 0.3-1.2 mm in size.

Advantages of Large Focal Spot

• A large actual focal spot is desirable to reduce the heat generated per unit area, increasing tube lifespan.

Target Angle Limitation

• The practical limit on how steep the target angle can be is around 7-10°, as excessive angling can lead to x-ray absorption.

X-ray Tube Rotation

• X-ray tubes typically rotate at a standard speed of 3,600 rpm during exposure.

Purpose of High-Speed Rotation

• High-speed rotation is used to dissipate heat generated by the electron beam, preventing tube damage.

Target Angle

• The target angle in x-ray tubes typically ranges from 7-10°.

Maximum Target Angle

• The maximum target angle in x-ray tubes is around 10°.

Delay after Exposure Button Pushed

• During the short delay after the exposure button is pushed, the x-ray tube rotates to the correct position, and high voltage is generated before the x-ray beam is produced.