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Measured lifetime of SF6-
Jyoti Rajput1, Lutz Lammich, Lars H Andersen
1Department of Physics and Astronomy, University of Aarhus, Aarhus C, Denmark.
Physical Review Letters
|June 4, 2008
Summary
The lifetime of the sulfur hexafluoride (SF6) anion was measured, revealing a nonexponential decay. This decay is explained by thermionic emission, considering initial molecular energy and electron kinetic energy.
Area of Science:
- Chemical Physics
- Atomic and Molecular Physics
- Plasma Physics
Background:
- The sulfur hexafluoride (SF6) anion is a key species in various chemical and physical processes.
- Understanding its stability and decay mechanisms is crucial for applications in plasma technology and atmospheric chemistry.
Purpose of the Study:
- To accurately measure the lifetime of the SF6 anion.
- To elucidate the decay mechanisms governing the SF6 anion's stability.
Main Methods:
- Utilizing the electrostatic ion storage ring ELISA for precise lifetime measurements.
- Recording anion decays over a time span from 100 microseconds to several seconds.
Main Results:
- Observed a nonexponential decay pattern for the SF6 anion.
- Characterized the decay by an approximate t(-1.5) power-law dependence.
- The decay rate is modeled by thermionic emission, incorporating initial SF6 molecule energy spread and electron kinetic energy.
Conclusions:
- The measured decay rate aligns with a thermionic emission model.
- The electron affinity of SF6 can be determined from the energy-dependent decay rate using an Arrhenius constant.
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