One-dimensional parallax-free position-sensitive detector for diffraction measurements based on a home-made thin...

Area of Science:

• Materials Science
• Particle Detectors
• Synchrotron Radiation

Background:

• Powder diffraction is crucial for material analysis.
• Parallax errors can limit the accuracy of gas detectors.
• Advancements in detector technology are needed for higher precision.

Purpose of the Study:

• To develop a large, parallax-free gas diffraction meter.
• To improve angular resolution in powder diffraction measurements.
• To achieve a broad dynamic range for enhanced data acquisition.

Main Methods:

• Utilized a thinner-THGEM (thick gaseous electron multiplier) with a 200 µm thickness, shaped into a curve.
• Designed a detector with a 48° open angle, positioned 20 cm from powder samples.
• Employed a 128-channel direct-current front-end electronics board for an 8 keV BSRF beamline.

Main Results:

• Achieved a parallax-free measurement capability by curving the THGEM.
• Obtained an angular resolution of 0.148 ± 0.081° for TiO₂ and SnO₂ powder samples.
• Demonstrated a broad dynamic range of approximately 10⁷ by combining gas gain and electronic dynamic range.

Conclusions:

• The developed gas diffraction meter effectively eliminates parallax errors.
• The detector provides high-precision measurements consistent with standard powder diffraction data.
• The technology offers a significant advancement for synchrotron-based powder diffraction studies.