A WISER way for simulating the performance of gratings

Area of Science:

• Optics and X-ray Physics
• Synchrotron Radiation Technology

Background:

• Soft X-ray monochromators are crucial for synchrotron radiation sources, with optics quality significantly improved.
• Groove placement errors in diffraction gratings remain a major, unresolved issue limiting monochromator performance.
• High-coherence X-ray sources necessitate accurate simulation of these errors for optimal performance.

Purpose of the Study:

• To present a novel simulation approach for predicting the impact of groove placement errors on X-ray monochromator performance.
• To demonstrate the application of the WISER (Wavefront propagatIon Simulation codE libRary) package for simulating diffraction grating performance.
• To introduce a simple method for estimating groove placement quality using the Strehl ratio.

Main Methods:

• Utilized the WISER physical optics simulation package, integrated within the Orange Synchrotron Radiation Suite (OASYS).
• Applied WISER to simulate the performance of diffraction gratings, adapting its original use for X-ray mirrors.
• Calculated the Strehl ratio to establish a rule for estimating groove placement accuracy.

Main Results:

• WISER effectively simulates the performance of periodic structures like diffraction gratings, despite its origin in mirror defect analysis.
• The study demonstrates a practical application of WISER in designing monochromators for upgraded beamlines.
• A new, simple rule based on Strehl ratio calculation provides an estimate of groove placement quality.

Conclusions:

• WISER offers a powerful tool for simulating groove placement errors in X-ray monochromators, addressing a long-standing challenge.
• The developed simulation method is vital for optimizing monochromator design, especially for advanced coherent X-ray sources.
• The Strehl ratio-based estimation provides a practical metric for assessing grating quality in X-ray optics.