Heat transfer 2

Question 1

How does heat radiation from the focal spot dissipate?

Answer 1

Heat radiation from the focal spot passes through the vacuum of the X-ray tube to be absorbed by the glass envelope and the oil.

Question 2

What is the role of conduction in heat dissipation?

Answer 2

Conduction takes place through the tungsten target into the copper anode block and then along the anode stem.

Question 3

How does convection contribute to heat loss in an X-ray tube?

Answer 3

The end of the anode stem is in contact with the oil surrounding the X-ray tube, setting up convection currents and warming the oil.

Question 4

What happens when the oil in the X-ray tube heats up?

Answer 4

The oil expands and compresses the bellows, which may actuate a microswitch to prevent further exposures.

Question 5

How does the warm casing of the X-ray tube contribute to heat dissipation?

Answer 5

The warm casing sets up convection currents in the air of the room.

Question 6

What materials are used to maximize heat transfer by conduction?

Answer 6

Copper, tungsten, or molybdenum due to their high thermal conductivity and large heat capacity.