Tunneling from electron bubbles beneath the surface of liquid helium

Schoepe and Rayfield have measured the lifetime Τ for escape of electrons from bubbles beneath a liquid He surface. We compute Τ using the tunneling Hamiltonian method of Bardeen. If accepted bubble parameters are assumed, Τ is found to be approximately two orders of magnitude smaller than the measured value. Agreement with experiment can be obtained if the radius is taken to be 50% larger than currently believed. We consider the effects of diffuseness of the bubble boundary, diffuseness of the liquid-vapor interface, and polarizability of the bubble. A discrepancy remains which may be explicable in terms of surface deformation when the bubble is very close to the surface.