I'm performing a steady state thermal analysis and one of the loads is an x-ray with known power and incident size. However, I can't simply model this load as occurring only on the surface since it penetrates the material with exponentially decreasing power. The power vs penetration depth is known. So I'm wondering if there is a way to specify the power of a component to vary within that component as a function of position? The only way I can currently think to do this is to have multiple thin stacked layers within the part and to apply a separate power load to each of them, scaling them according to the power vs penetration curve and making sure they sum up to the total power. Is there a better way to do this?

Much appreciated.