Optical measurements

The optical characteristics of the electrons in the bubble state are of considerable fundamental interest and importance: these properties reflect the nature of the group and excited states of localized electrons in one of the simplest condensed-matter environment. These issues relate principally to the fluorescence efficiency, non-radiative relaxation channels, and line broadening mechanisms for these states
- Use absorption spectroscopy to record the 1s-1p and 1s-2p transitions in LHe to determine the absorption cross-section and examine the spectral features of the transitions
- Detect the electron bubbles by laser-induced fluorescence. An important question concerns the characteristics of the fluorescence emission spectrum
- Examine the nature of the electron emission process directly at the surface for electron bubbles trapped in the potential well formed at the liquid/vapor interface.
- Determine the photon-energy thresholds and emission efficiencies