Low energy (e,2e) coincidence studies of NH3: Results from experiment and theory

Abstract

Experimental and theoretical triple differential cross sections (TDCS) from ammonia are presented in the low energy regime with outgoing electron energies from 20 eV down to 1.5 eV. Ionization measurements from the 3a1, 1e1, and 2a1 molecular orbitals were taken in a coplanar geometry. Data from the 3a1 and 1e1 orbitals were also obtained in a perpendicular plane geometry. The data are compared to predictions from the distorted wave Born approximation and molecular-three-body distorted wave models. The cross sections for the 3a1 and 1e1 orbitals that have p-like character were found to be similar, and were different to that of the 2a1 orbital which has s-like character. These observations are not reproduced by theory, which predicts the structure of the TDCS for all orbitals should be similar. Comparisons are also made to results from experiment and theory for the iso-electronic targets neon and methane.

Sulphur hexaflouride: low energy (e,2e) experiments and molecular three-body distorted wave theory

“…There have been a multitude of experimental investigations of electron collisions with SF 6 . Initially, these processes were studied due to SF 6 having a series of shape resonances [1].…”

“…Its primary use is as a common insulating gas in the electrical industry, due to SF 6 having an electrical breakdown strength three times that of air. SF 6 is used as a plasma etching gas in the semiconductor industry, and is also used during the manufacture of magnesium to protect the molten magnesium from oxidants such as air.…”

“…Sulphur hexafluoride (SF 6 ) is an important molecule that is used in many technological and industrial applications due to its physical properties of being non-flammable, non-toxic, non-corrosive and relatively inert. Its primary use is as a common insulating gas in the electrical industry, due to SF 6 having an electrical breakdown strength three times that of air.…”

“…Additionally, it is used as the halogen donor in rare gas-halide excimer lasers. While SF 6 is an important gas with many applications, the use of this gas is carefully monitored and controlled, as SF 6 is a known greenhouse gas which has a very high global warming potential (GWP). SF 6 has a strong absorption band in the infra-red, and as such effectively traps radiation that normally is emitted from the earth into space.…”

“…While SF 6 is an important gas with many applications, the use of this gas is carefully monitored and controlled, as SF 6 is a known greenhouse gas which has a very high global warming potential (GWP). SF 6 has a strong absorption band in the infra-red, and as such effectively traps radiation that normally is emitted from the earth into space. Further, since SF 6 has a low probability of photo-dissociation in the atmosphere, this molecule has a very long lifetime in the stratosphere, which contributes further to its high GWP ranking.…”