X-ray spectrometer throughput model for (selected) flat Bragg crystal spectrometers on laser plasma facilities

Area of Science:

• Plasma Physics
• Spectroscopy
• Optical Engineering

Background:

• X-ray spectrometers are crucial for diagnosing plasma conditions and monitoring backlighters at major laser facilities.
• Calibration of these spectrometers is often outdated or unknown, limiting diagnostic accuracy.
• Accurate calibration is essential for reliable experimental data.

Purpose of the Study:

• To develop a straightforward ray tracing method for calibrating flat crystal x-ray spectrometers.
• To provide a practical solution for addressing unknown or outdated spectrometer calibrations.
• To enable accurate photometric throughput, dispersion, solid angle, and spectral resolution estimates.

Main Methods:

• A simple ray trace model was developed using fundamental optical design parameters.
• The model was applied to specific spectrometers at the National Ignition Facility (NIF) and OMEGA laser facility.
• The method requires only basic information about the spectrometer's optical design.

Main Results:

• The ray trace method successfully calibrated flat crystal spectrometers.
• Photometric throughput, dispersion, solid angle, and spectral resolution were estimated.
• The model was validated on the mono angle crystal spectrometer and Super Snout I at NIF, and the X-Ray Spectrometer at OMEGA.

Conclusions:

• The developed ray trace method offers a simple and effective way to calibrate x-ray spectrometers.
• This approach enhances the reliability of plasma diagnostics and backlighter monitoring at large laser facilities.
• Accurate calibration is achievable using basic optical design information, improving experimental outcomes.