Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Technikerstr. 25, A-6020 Innsbruck, Austria.
Departamento de Física-ICE, Universidade Federal de Juiz de Fora, Campus Universitário, 36036-900, Juiz de Fora, MG, Brazil.
Phys Rev Lett. 2019 Oct 18;123(16):165301. doi: 10.1103/PhysRevLett.123.165301.
We report on the production and study of stable, highly charged droplets of superfluid helium. Using a novel experimental setup we produce neutral beams of liquid helium nanodroplets containing millions of atoms or more that can be ionized by electron impact, mass-per-charge selected, and ionized a second time before being analyzed. Droplets containing up to 55 net positive charges are identified and the appearance sizes of multiply charge droplets are determined as a function of the charge state. We show that the droplets are stable on the millisecond timescale of the experiment and decay through the loss of small charged clusters, not through symmetric Coulomb explosions.
我们报告了超流氦稳定、高电荷液滴的产生和研究。使用一种新颖的实验装置，我们产生了含有数百万个原子或更多原子的中性液氦纳米液滴束，这些液滴可以通过电子碰撞电离，按质荷比选择，并在被分析之前再次被电离。我们识别出含有多达 55 个净正电荷的液滴，并确定了多电荷液滴的表观尺寸作为电荷状态的函数。我们表明，液滴在实验的毫秒时间尺度上是稳定的，并通过小的带电团簇的损失而衰减，而不是通过对称的库仑爆炸。
