Synchronized beamline at FLASH2 based on high-order harmonic generation for two-color dynamics studies

Area of Science:

• Atomic and Molecular Physics
• Ultrafast Science
• Synchrotron Radiation and FELs

Background:

• The Free-Electron Laser FLASH facility requires advanced beamlines for cutting-edge research.
• Investigating ultrafast dynamics in atomic and molecular systems necessitates tunable, ultrashort light sources.

Purpose of the Study:

• To design, integrate, and operate a novel vacuum ultraviolet (VUV) beamline at the FLASH facility.
• To couple ultrashort VUV pulses (10-40 eV) generated by high-order harmonic generation (HHG) with the FEL.
• To enable time-resolved studies of ultrafast dynamics using a reaction microscope (REMI) endstation.

Main Methods:

• Installation of a novel VUV beamline (FL26) at the FLASH FEL.
• Utilizing high-order harmonic generation (HHG) in gas, driven by a synchronized optical laser.
• Coupling the HHG source with the FEL and integrating a reaction microscope (REMI) endstation.
• Implementing a compact and reliable interface system to manage vacuum requirements.

Main Results:

• Successful commissioning and operation of the VUV beamline.
• Achieved a focused VUV beam size of approximately 20 µm at the REMI endstation.
• Demonstrated proof-of-principle photo-electron momentum measurements in argon.

Conclusions:

• The novel VUV beamline is successfully integrated and operational at FLASH.
• The beamline is capable of supporting advanced time-resolved ultrafast dynamics studies.
• The system shows potential for future two-color pump-probe experiments.