Thermal loads of X-ray tubes with a fixed anode under long-duration exposure

The procedure suggested in [1, 2] is used to analyze the dynamics of temperature field in a multilayer fixed anode (material № 1/$\mathrm{AgSn}/\mathrm{Cu}$) of a water-cooled X-ray tube in the process of being irradiated by an electron beam. The limiting power and the surface power density of electron beam on the anode surface being irradiated are estimated, which correspond to the preassigned value of density of vapors of the target material. The dependence of these quantities on the beam size, type of target material, and its thickness is investigated.