Question

CT xray tube arcing can occur because of _________ the xray tube?

1) impurities in the oil outside
2) tungsten gas inside
3) tungsten solids in the oil inside

Answer 1

CT x-ray tube arcing can be caused by the presence of tungsten solids in the oil inside the tube. Arcing is tied to the interaction of high-energy photons with heavy elements like tungsten, which require a high accelerating voltage for characteristic x-ray production.

Step-by-step explanation:

CT x-ray tube arcing can occur because of certain conditions within the x-ray tube itself. One reason for arcing is the presence of impurities, such as tungsten solids in the oil inside the tube. During operation, the x-ray tube generates large photon energy typical of characteristic x-rays from heavy elements like tungsten. These characteristic x-rays are a result of inner-shell vacancy fillings, which require significant accelerating voltage to occur.

For tungsten, at least 72.5 kV is necessary to create these vacancies since you cannot 'bump' an electron to a higher filled shell; it must be removed from the atom. The high melting point and thermal durability of tungsten make it an ideal choice for the anode material in x-ray tubes to manage the high energy and temperature.