\text { Calculate the volume of the intersection of the closed ball }\left\{(x, y, z) \in \mathbb{R}^{3} \mid x^{2}+\right. \left.y^{2}+z^{2} \leq a^{2}\right\} \text { and the cylindrical column }\left\{(x, y, z) \in \mathbb{R}^{3} \mid x^{2}+y^{2} \leq a x, z \in \mathbb{R}\right\}