Communication: atomic and molecular Rydbergs from water.

Area of Science:

• Atomic and Molecular Physics
• Physical Chemistry
• Astrochemistry

Background:

• Energetic neutral atoms and molecular ions are observed in various environments.
• Understanding the formation mechanisms of these species is crucial for atmospheric and biological studies.
• Water molecules are ubiquitous and play a significant role in many chemical processes.

Purpose of the Study:

• To investigate the formation of energetic neutral Rydberg hydrogen atoms and transient Rydberg molecular ions from ion-impact dissociation of isolated water molecules.
• To analyze the kinetic energy spectra of the resulting neutral Rydberg hydrogen atoms.
• To explore the potential implications of this dissociation channel for astrophysical observations and radiation biology.

Main Methods:

• Ion-impact dissociation experiments on isolated water molecules.
• Analysis of kinetic energy spectra of neutral Rydberg hydrogen atoms.
• Characterization of the (H(⋆), H(+), O(+)) dissociation channel.

Main Results:

• Successful formation of energetic neutral Rydberg hydrogen atoms and transient Rydberg molecular ions was observed.
• Kinetic energy spectra of the neutral Rydberg hydrogen atoms were determined.
• The (H(⋆), H(+), O(+)) dissociation channel was identified as a source of these energetic species.

Conclusions:

• Ion-impact dissociation of water molecules is a viable pathway for generating energetic neutral Rydberg hydrogen atoms and transient Rydberg molecular ions.
• This process offers a potential explanation for energetic neutral species detected in exoplanet atmospheres.
• The study highlights a possible source of slow electrons relevant to radiation-induced cellular damage.