In order for an anion to neutralize, it has to get rid of its excess electron. It does so by coupling to internal states of its neutral counterpart. For a molecule this process is commonly believed to be (mostly) insensitive to its rotational excitation. However, this study shows that for C2− large rotation can “reshuffle” the positions of the electronic states both inside the negatively charged system and with respect to its neutral equivalent, C2. As a result, the time scales in which the different decay processes occur change by many orders of magnitude. In the case of the third electronic excited state of C2−, the lifetime of the autodetachment channel, in which the excess electron is spontaneously ejected, increases from femtoseconds to many seconds depending on the rotational excitation. This lifetime enhancement is caused by the inaccessibility of “conventional” autodetachment mechanisms, requiring a newly described process where the ejected electron takes away multiple quanta of rotational excitation. The lifetime of anions, which detach electrons that carry away six quanta of angular momentum match the decay signal measured at multiple ion storage facilities throughout the world.
Original publication:
Autodetachment of diatomic carbon anions from long-lived high-rotation quartet states
Viviane C. Schmidt, Roman Čurík, Milan Ončák, Klaus Blaum, Sebastian George, Jürgen Göck, Manfred Grieser, Florian Grussie, Robert von Hahn, Claude Krantz, Holger Kreckel, Oldřich Novotný, Kaija Spruck and Andreas Wolf
Physical Review Letters 133, 183001 (2024). DOI: 10.1103/PhysRevLett.133.183001
Unimolecular processes in diatomic carbon anions at high rotational excitation
Viviane C. Schmidt, Roman Čurík, Milan Ončák, Klaus Blaum, Sebastian George, Jürgen Göck, Manfred Grieser, Florian Grussie, Robert von Hahn, Claude Krantz, Holger Kreckel, Oldřich Novotný, Kaija Spruck and Andreas Wolf
Physical Review A 110, 042828 (2024). DOI: 10.1103/PhysRevA.110.042828
Weblinks:
The Cryogenic Storage Ring CSR at MPIK
