New source of MeV negative ion and neutral atom beams

Area of Science:

• Atomic and Molecular Physics
• Beam Physics
• Surface Science

Background:

• The
• electron-capture and -loss
• model explains MeV kinetic energy ion and neutral atom beam formation.
• However, it fails to account for the significantly higher efficiency of negative ion formation in liquid sprays compared to isolated atoms.

Purpose of the Study:

• Investigate the underlying mechanisms behind efficient negative ion formation in liquid sprays.
• Evaluate the role of atomic excited states in charge-exchange processes.
• Propose a more comprehensive model for ion and atom beam formation.

Main Methods:

• Theoretical analysis of electron-capture and -loss processes.
• Consideration of atomic excited states' influence on charge exchange.
• Exploration of projectile ion and target atom electronic structures.

Main Results:

• The simple
• electron-capture and -loss
• model does not fully explain the observed phenomena.
• Atomic excited states do not adequately account for the enhanced efficiency in liquid sprays.
• The processes involved are more complex than previously assumed.

Conclusions:

• The formation of negative ions and neutral atom beams, particularly in liquid sprays, involves complex processes beyond single electron transfer.
• Shell effects in the electronic structure of ions and atoms likely play a crucial role in influencing capture/loss probabilities.
• Further research is needed to elucidate these complex interactions for accurate beam formation modeling.