Which of these practices is least likely to prolong the life of an x-ray tube?

Using the maximum mA setting is least likely to prolong the life of an x-ray tube. The mA (milliampere) setting controls the tube current, which affects the quantity of radiation produced. When operating at the maximum mA, there is increased thermal stress on the anode, leading to a higher risk of overheating and potential damage over time. This high demand can lead to quicker wear and degradation of the tube components.

In contrast, practices such as warming up the anode are essential for maintaining tube integrity. Warming up helps to evenly distribute the heat across the anode and prevent thermal shock. Utilizing low-speed rotors also contributes positively by reducing wear on the bearings and facilitating lower heat generation. Similarly, using lower mA settings minimizes the thermal load, which can significantly extend the operational life of the x-ray tube. Each of these protective measures enhances the overall longevity and reliability of the x-ray machine.