X-ray beam expansion system based on an asymmetric cut crystal

Area of Science:

• X-ray optics
• Astronomy instrumentation
• Crystallography

Background:

• Ground testing and calibration of X-ray telescope imaging optical systems are essential for ensuring instrument performance and mission success.
• Large-dimension, highly collimated X-ray beams are required to cover the full aperture of telescopes during calibration.

Purpose of the Study:

• To investigate the application requirements for large-sized X-ray beams in ground testing of X-ray telescope imaging optical systems.
• To develop and study an X-ray beam expansion system utilizing an asymmetric cut crystal.

Main Methods:

• X-rays from a Ti-target source were diffracted by a symmetric Si(220) crystal for monochromaticity.
• An asymmetric cut Si(220) crystal was used for one-dimensional X-ray beam expansion.
• The mounting position and rocking curve of the asymmetric crystal were optimized.

Main Results:

• The asymmetric cut crystal achieved a beam expansion width of approximately 30mm.
• An effective expansion ratio (b) of 41 was obtained.
• The maximum total count rate of the diffraction peak reached 129 cps.

Conclusions:

• The developed asymmetric cut crystal system provides a viable method for generating large-sized X-ray beams.
• These findings offer technical support for establishing ground testing and calibration devices for X-ray telescopes.