Since their discovery by Röntgen (1) in 1895, x-ray imaging and spectroscopy have revolutionized disciplines as diverse as astrophysics, materials science, chemistry, and the life sciences. However, in the medical context, x-rays are also known for their darker side: They damage tissue. Although even that destructive nature is turned into a benefit in radiation therapy, on a fundamental level, x-rays damage atoms from the inside out: They typically kick out deeply bound electrons, punching a “core hole” into the atom. This unstable situation unleashes a cascade of electronic relaxation events that turn neutral atoms into ions, thus breaking chemical bonds in molecules or creating defects in solids. On page 1630 of this issue, Eichmann et al. (2) show how to outpace the radiation damage of x-rays on the fundamental, single-atom level. They detect neutral neon atoms that are just slightly excited, not damaged. Counterintuitively at first, this process benefits from the extremely intense x-rays supplied by a free-electron laser (FEL).

自从Röntgen（1）于1895年发现X射线成像和光谱学以来，它彻底改变了天体物理学，材料科学，化学和生命科学等学科。但是，在医学上，X射线也因其较暗的一面而闻名：它们会损伤组织。尽管即使是破坏性的性质也变成了放射治疗的好处，但从根本上讲，X射线从内到外破坏原子：它们通常将深结合的电子踢出，在原子上打一个“核心孔”。这种不稳定的情况引发了一系列电子弛豫事件，这些弛豫事件将中性原子转变为离子，从而破坏了分子中的化学键或在固体中产生了缺陷。在此问题的第1630页上，Eichmann等人。（2）展示了如何在基本的单原子水平上超过X射线的辐射损伤。他们检测到中性氖原子，只是被激发而没有被破坏。首先，与直觉相反，此过程受益于自由电子激光器（FEL）提供的极强的X射线。