Highly charged droplets of superfluid helium

TL;DR

This study demonstrates the production and analysis of highly charged, stable superfluid helium droplets, revealing their stability and decay mechanisms under multiple charge states using a novel experimental approach.

Contribution

Introduces a new experimental method to produce and analyze highly charged superfluid helium droplets, showing their stability and decay processes.

Findings

Droplets with up to 55 positive charges identified

Droplets are stable on millisecond timescales

Decay occurs via loss of small charged clusters

Abstract

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 charge state. We show that the droplets are stable on the millisecond time scale of the experiment and decay through the loss of small charged clusters, not through symmetric Coulomb explosions.