多重散射

Multiple scattering

Here an electron undergoes more than 20 scattering events as it passes through a specimen. This would only occur on rare occasions, e.g. with very thick or dense specimens.

入射電子射向物質時，會多次受到物質中多個電子或原子核的散射（即多次散射），從而使得入射電子在遭到多次碰撞以後，其在各個方向上的散射概率趨於一致。由於散射截面與原子序數的平方成正比，因而對於輕元素，其散射的概率要小於重元素。