Electron shell ionization of atoms with classical, relativistic scattering

Area of Science:

• Atomic Physics
• Quantum Electrodynamics
• Plasma Physics

Background:

• Investigating electron scattering dynamics in intense laser fields is crucial for understanding atomic ionization processes.
• Ultrahigh laser intensities (2 × 10^19 W/cm^2) push the boundaries of classical and quantum descriptions of matter-light interactions.

Purpose of the Study:

• To investigate the forward scattering of photoelectrons from neon, argon, and xenon atoms ionized by ultrahigh intensity lasers.
• To analyze the influence of atomic shell structure on photoelectron angular distributions and yield.
• To compare experimental observations with theoretical predictions based on advanced atomic and field models.

Main Methods:

• Utilizing ultrahigh laser intensities (2 × 10^19 W/cm^2) to ionize neon, argon, and xenon.
• Measuring the angular distributions and energies of outgoing photoelectrons.
• Employing an independent electron model, dipole approximation, and a relativistic classical radiation field for theoretical comparison.

Main Results:

• Photoelectron energy directly correlates with momentum, enabling forward scattering up to 45° from the laser wave vector for energies >1 MeV.
• Atomic shell structure causes observable modulations in photoelectron yield and the width of angular distributions.
• Experimental results show strong agreement with theoretical predictions.

Conclusions:

• The study validates theoretical models for atomic ionization in ultrahigh laser fields.
• Provides insights into atomic physics relevant to plasma, radiation, and particle acceleration in extreme conditions.
• Demonstrates the significant role of electron energy and atomic structure in scattering dynamics.