A multi-plate velocity-map imaging design for high-resolution photoelectron spectroscopy

Area of Science:

• Atomic and Molecular Physics
• Chemical Physics
• Spectroscopy

Background:

• Velocity map imaging (VMI) is a powerful technique for analyzing charged particles.
• Optimizing VMI resolution and functionality is crucial for detailed molecular studies.
• Existing VMI setups may have limitations in energy range, interaction volume, or adaptability.

Purpose of the Study:

• To present a novel VMI setup designed for slow electron applications.
• To discuss design parameters influencing VMI resolution and functionality.
• To demonstrate the VMI's performance with specific anion photoelectron spectra.

Main Methods:

• Developed a VMI apparatus with multiple electrodes and adjustable voltage parameters.
• Incorporated tunable potentials for optimal focus across a broad energy range.
• Coupled the VMI to a cryogenic ion trap mass spectrometer with a flexible source.
• Acquired photoelectron spectra of S⁻ and CS₂⁻ anions.

Main Results:

• Achieved good VMI focus over a large energy range.
• Enabled larger interaction volumes with minimal resolution loss.
• Demonstrated the VMI's capability by analyzing S⁻ and CS₂⁻ photoelectron spectra.
• Probed temperature-dependent vibronic features in CS₂⁻.

Conclusions:

• The presented VMI design offers enhanced resolution and flexibility for slow electron studies.
• The tunable potentials and electrode design allow for optimized performance.
• The VMI system is suitable for investigating molecular properties, including temperature-dependent effects.