Rapidly stripping off multiple electrons from the target and triggering complete fragmentation with each constituent atom being charged up are ideal prerequisites for Coulomb explosion imaging. Here, we demonstrate that highly charged ion beam with energy in the Bragg peak region is a powerful tool capable of meeting these requirements. Using the 112.5  keV/u C5+ beam, we successfully imaged the structures of pyridazine, pyrimidine, and pyrazine, three isomers of C4⁢H4⁢N2, by detecting ionic fragments H+, C2+, C+, and N+ in quadruple coincidence. The three isomers are unambiguously distinguished in the spectra of angular correlation between different fragments, and their structures are clearly visualized in momentum images. More importantly, taking the advantage of fast colliding interaction that creates high charge states on a subfemtosecond timescale, our approach effectively suppresses the distortion of molecular configuration during explosion, ensuring the high accuracy in structural imaging. This is confirmed by the quantitative agreement of momentum magnitudes between the point-charge model and the experiment for all fragments including hydrogen. Our work demonstrates that highly charged ion induced Coulomb explosion is a powerful tool for precisely imaging the initial structures of complex molecules.

中文翻译：

---

使用高电荷离子对复杂分子进行库仑爆炸成像


从靶材上快速剥离多个电子并在每个组成原子充电时触发完全碎裂是库仑爆炸成像的理想先决条件。在这里，我们证明了布拉格峰区域中具有能量的高电荷离子束是能够满足这些要求的强大工具。使用 112.5 keV/uC5 + 束，我们通过检测离子片段 H+、C2+、C+ 和 N+ 成功地对 C4H4N2 的三种异构体吡哒嗪、嘧啶和吡嗪的结构进行了成像四重巧合。这三种异构体在不同片段之间的角度相关光谱中明确区分，它们的结构在动量图像中清晰可见。更重要的是，利用在亚飞秒时间尺度上产生高电荷态的快速碰撞相互作用，我们的方法有效地抑制了爆炸过程中分子构型的失真，确保了结构成像的高精度。点电荷模型和实验之间包括氢在内的所有碎片的动量大小的定量一致性证实了这一点。我们的工作表明，高电荷离子诱导的库仑爆炸是精确成像复杂分子初始结构的有力工具。