Presentation #111.03 in the session Laboratory Astrophysics Division (LAD): The Role of Laboratory Plasma Experiments in Astrophysics.
A radio-frequency hydrogen plasma is cooled to cryogenic temperatures, into which water vapor is injected. The water vapor freezes on contact with the cold ionized gas and spontaneously forms ice particulates, which are electrostatically confined within the plasma, and grow into elongated structures reaching hundreds of microns in length. Ice nucleation, growth, and morphology are shown to be dependent on the plasma properties, and Fourier Transform Infrared Spectroscopy (FTIR) is used to examine the spectral signature of the ice and determine how the ice’s microstructure is affected by changes in the plasma. Results of spectroscopy and microscopic imaging of these ice grains will be presented. Results have possible relevance to ice particulates in planetary and astrophysical plasmas, including Enceladus’ icy plumes, planetary rings, and molecular clouds.
Supported by NSF/DOE Partnership in Plasma Science and Engineering via DOE Award DE-SC0020079.