Multiply Charged Helium Droplet Anions

• Published in: Chemistry : a European journal Vol. 27; no. 25; pp. 7283 - 7287
• Main Authors: Laimer, Felix, Zappa, Fabio, Scheier, Paul, Gatchell, Michael
• Format: Journal Article
• Language: English
• Published: Germany Wiley Subscription Services, Inc 03.05.2021; John Wiley and Sons Inc
• Subjects: Anions; charge carriers; Chemistry; Current carriers; Droplets; Fluids; Helium; helium droplets; Ions; Liquid helium; multiple charges; superfluid; Superfluidity; Water chemistry; superfluid; multiple charges; charge carriers; helium droplets
• ISSN: 0947-6539; 1521-3765; 1521-3765
• DOI: 10.1002/chem.202005004

The detection of multiply charged helium droplet anions is reported for the first time. By ionizing droplets of superfluid helium with low energy electrons (up to 25 eV), it was possible to produce droplets containing up to five negative charges, which remain intact on the timescale of the experiment. The appearance sizes for different charge states are determined and are found to be orders of magnitude larger than for the equivalent cationic droplets, starting at 4 million He atoms for dianions. Droplets with He*− as charge carriers show signs of being metastable, but this effect is quenched by the pickup of water molecules. Charged droplets: The detection of multiply charged helium droplet anions is reported for the first time. By ionizing droplets of superfluid helium with low energy electrons (up to 25 eV), it was possible to produce droplets containing up to five negative charges, which remain intact on the timescale of the experiment.