Cascade contribution to the H2 Lyman band system from electron impact
Abstract
The intensity of UV resonance transitions excited by electron impact is determined by both direct excitation and cascade processes. The lifetime for decay by spontaneous emission from a resonant state is short (typically < 10 ns). Using a pulsed electron gun technique established to separate these two effects we report a laboratory study of the UV spectrum of H2 attributed to cascade. We utilize the longer lifetimes (> 30 ns) for cascade channels to measure the intense spectrum of the Lyman band system (B 1Σ+u-X 1Σ+g) of H2 populated by cascade from higher lying (EF,GK,H1Σ+g) states.
- Publication:
-
Physical Review A
- Pub Date:
- June 2000
- DOI:
- 10.1103/PhysRevA.61.064702
- Bibcode:
- 2000PhRvA..61f4702D
- Keywords:
-
- 34.50.Gb;
- 34.80.Gs;
- Electronic excitation and ionization of molecules;
- intermediate molecular states;
- Molecular excitation and ionization by electron impact