The anode heel effect. The strength of the radiation is weaker in anode as compared to the cathode. The effect stems from the absorption of the X-ray photons as they leave the anode. The effect varies with the heel angle of the anode (α, β). In an anode with a smaller heel angle (α), the X-ray photons have to traverse a longer distance to exit the anode. This attenuates the X-ray photons more. By contrast, in an anode with a larger heel angle (β), the X-ray photons have to traverse a shorter distance to exit the anode. The radiation is thus stronger. In either instance, however, the radiation towards the anode is less than that towards the cathode.