Electron impact ionization of helium nano-droplets containing several 104 He atoms and doped with CCl4 or SF6 molecules is studied with high-mass resolution. The mass spectra show significant clustering of CCl4 molecules, less so for SF6 under our experimental conditions. Positive ion efficiency curves as a function of electron energy indicate complete immersion of the molecules inside the helium droplets in both cases. For CCl4 we observe the molecular parent cation CCl4+ that preferentially is formed via Penning ionization upon collisions with He*. In contrast, no parent cation SF6+ is seen for He droplets doped with SF6. The fragmentation patterns for both molecules embedded in He are compared with gas phase studies. Ionization via electron transfer to He+ forms highly excited ions that cannot be stabilized by the surrounding He droplet. Besides the atomic fragments F+ and Cl+ several molecular fragment cations are observed with He atoms attached.
Authors
- Harald Schobel,
- dr inż. Marcin Dampc link open in new tab ,
- Da Silva Filipe Ferreira,
- Andreas Mauracher,
- Fabio Zappa,
- Stephan Denifl,
- Mark D. Tilmann,
- Paul Scheier
Additional information
- Category
- Publikacja w czasopiśmie
- Type
- artykuł w czasopiśmie wyróżnionym w JCR
- Language
- angielski
- Publication year
- 2009
