Cavitation of electron bubbles in liquid parahydrogen

Abstract

Within a finite-temperature density functional approach, we have investigated the structure of electron bubbles in liquid parahydrogen below the saturated vapour pressure, determining the critical pressure at which electron bubbles explode as a function of temperature. The electron–parahydrogen interaction has been modelled by a Hartree-type local potential fitted to the experimental value of the conduction band-edge for a delocalized electron in pH₂. We have found that the pressure for bubble explosion is, in absolute value, about a factor of two smaller than that of the homogeneous cavitation pressure in the liquid. Comparison with the results obtained within the capillary model shows the limitations of this approximation, especially as temperature increases.

Keywords:

• liquid parahydrogen
• electron bubbles
• density functional theory
• capillary approximation

Acknowledgements

This work has been performed under Grants No. FIS2008-00421/FIS and FIS2007-60133 from DGI, Spain (FEDER), and Grant 2009SGR01289 from Generalitat de Catalunya.