除了光电效应，原子世界还有另一种巧妙的能量传递方式。当内层电子被X射线激发后，高能级电子向低能级跃迁时释放的能量不一定都变成X射线光子。有时，这些能量会选择一条"捷径"，直接被周围某个壳层上的电子吸收，使这个电子受激发并逸出原子，成为二次电子。这就是俄歇效应，它就像是原子内部的"能量快递"，将能量直接从一个电子传递给另一个电子。---Extraction Content: Chart/Diagram Description: * **Type:** Schematic diagram illustrating an atomic interaction. * **Main Elements:** * **Nucleus:** Depicted at the center, labeled "Mg". Represented as a large blue sphere. * **Electron Shells:** Concentric circles surrounding the nucleus, labeled from inside out: K, L, M. The K shell is the innermost (black line), followed by L (green line), and M (blue line) as the outermost shell shown. * **Electrons:** Represented by small spheres. Some are grey, some are green, and two are blue. Grey spheres appear in the K shell, green spheres in the L and M shells, and blue spheres in the M shell. The diagram shows two grey electrons in the K shell, eight green electrons in the L shell (arranged in pairs), and some electrons in the M shell (two green, two blue shown). One blue electron is shown in the M shell at the top, and another is shown at the bottom. * **Incident X-ray:** An arrow pointing towards the atom from the top left, labeled "入射X射线" (Incident X-ray). * **Energy Transfer/Relaxation:** An orange arrow originates from a grey electron in the K shell and points towards a green electron in the L shell. This likely represents energy transfer or excitation. * **Secondary Electron:** A curved arrow originating from a green electron in the L shell points away from the atom to the right, ending near a small circle labeled "二次电子" (Secondary electron). The small circle is greenish-yellow with a brown outline. This indicates the ejection of an electron from the L shell. * **Relative Position and Direction:** The incident X-ray comes from the top left. The secondary electron is ejected towards the right. The nucleus is at the center. Shells K, L, M are concentric around the nucleus in increasing radius. Textual Information: * Label: 入射X射线 (Incident X-ray) * Label: Mg (within the nucleus) * Label: K (next to the innermost electron shell) * Label: L (next to the second electron shell) * Label: M (next to the third electron shell) * Label: 二次电子 (Secondary electron)