Berlin 2001 – wissenschaftliches Programm
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MO: Molekülphysik
MO 8: Posters Thursday: Dissociation and other Collision Processes
MO 8.11: Poster
Donnerstag, 5. April 2001, 12:30–15:00, AT3
Selective fragmentation of valence and core excited CD4 and SF6 molecules. — •Jaume Rius i Riu1, Peter Erman1, Andrzej Karawajczyk1, Elisabeth Rachlew1, Marek Stankiewicz2, and Piotr Winiarczyk2 — 1Section of Atomic and Molecular Physics, Department of Physics, Royal Institute of Technology, KTH, SE 10044, Stockholm, Sweden — 2Instytut Fizyki im. Mariana Smoluchoskiego, Uniwersytet Jagiellonski, ul. Reymonta 4, 30-059 Krakow, Poland
Electron-ion coincidence measurements with energy resolved electrons is a powerful tool in studies of molecular fragmentation processes. Presently, we have applied this technique in measurements of coincidence spectra of the CD4 molecule following valence and core electron excitation and fragmentation studies of the valence electron excited SF6 molecule. experiment has been carried out at the beam line I411 at the MAX laboratory in Lund using a 125 mm electron spectrometer and a 110 mm time-of-flight ion analyzer.
Our results show that the CD4+ molecule in the 1t2−1 state is stable or fragments into CD3+ + D. Quite spectacularly, none of these reaction occur from the 2a1−1 state where only the D+, CD+, and CD2+ fragments were observed. These results are the first demonstrating a correlation between nuclear motion and molecular dissociation in the CD4 molecule.
Our results of the coincidence measurement on SF6 show that the SF6+ molecule in the 1t1g−1 state is unstable and fully dissociates into the SF5+ + F channel. Also, the mass spectra acquired in coincidence with the 5t1u, 3eg, 1t2g and 5a1g electrons reveal a strong selectivity in dissociation from these states.