Camera for coherent diffractive imaging and holography with a soft-x-ray free-electron laser

Area of Science:

• Optics and Photonics
• Materials Science
• X-ray Physics

Background:

• Coherent scattering patterns are crucial for understanding material structures at the nanoscale.
• Soft-x-ray free-electron lasers (FELs) provide intense, tunable X-ray sources ideal for these studies.
• Existing detection methods face challenges with the high intensity and specific wavelengths of FELs.

Purpose of the Study:

• To design and implement a novel camera system for recording coherent scattering patterns generated by soft-x-ray FELs.
• To address the challenges posed by extreme FEL pulse intensities and spectral characteristics.
• To develop a versatile detection system applicable across a broad range of soft-x-ray wavelengths.

Main Methods:

• A camera system was developed incorporating a laterally graded multilayer mirror.
• The multilayer mirror functions as a bandpass filter, reflecting diffraction patterns onto a CCD detector.
• A central hole in the mirror allows the undiffracted beam to bypass the detector, preventing damage.

Main Results:

• The camera successfully recorded coherent scattering patterns from a soft-x-ray FEL.
• The multilayer mirror effectively filtered out unwanted scattering and incoherent emission.
• No observable mirror damage or performance degradation occurred during over 30,000 recorded diffraction patterns.

Conclusions:

• The developed camera system is effective for recording coherent scattering patterns with soft-x-ray FELs.
• The multilayer mirror design is robust against high-intensity FEL pulses.
• The system's design is adaptable for use with various soft-x-ray FEL wavelengths, including the water window.