ASNT Industrial Radiography Radiation Safety Practice Test

What is the role of a focusing cup in an X-ray tube?

1. To Increase Voltage

2. To Reduce Radiation Leakage

3. To Focus Electrons on the Target

4. To Maintain Amperage

The correct answer is: To Focus Electrons on the Target

The role of a focusing cup in an X-ray tube is to focus electrons on the target. In an X-ray tube, the focusing cup is typically made of metal and has a negative charge, which helps to direct the flow of electrons emitted by the cathode toward the anode. By concentrating these electrons into a smaller area, the focusing cup enhances the efficiency of X-ray production, allowing for a more focused and intense beam of radiation to be generated. This focused beam is essential for producing high-quality images in radiographic procedures, as it improves the resolution and contrast of the resulting images. The effective concentration of electrons on the target also contributes to minimizing the spread of radiation and optimizing the performance of the X-ray tube.