MYTHEN III: advancements in single photon counting detectors for synchrotron powder diffraction experiments

Area of Science:

• Synchrotron Radiation Science
• Materials Science Instrumentation
• Particle Detection Technology

Background:

• Synchrotron radiation experiments require advanced detectors for high-performance measurements.
• Existing detectors face limitations in count rate and efficiency for time-resolved studies.
• The MYTHEN II detector provided a foundation for further advancements.

Purpose of the Study:

• To introduce the MYTHEN III single photon counting microstrip detector.
• To detail its improved performance characteristics compared to its predecessor.
• To demonstrate its utility in time-resolved and on-edge powder diffraction.

Main Methods:

• Development of the MYTHEN III detector based on the MYTHEN III.0 readout chip and silicon strip sensors.
• Utilizing three independent comparators for pile-up detection and improved count rate.
• Implementing digital on-chip interpolation and pump-probe operation modes.
• Performance benchmarking including count rate, frame rate, minimum detectable energy, and noise characteristics.

Main Results:

• Achieved a maximum count rate capability of 11 ± 2 Mphotons s⁻¹ strip⁻¹ at 90% efficiency, a significant increase from MYTHEN II.
• Maximum frame rate up to 360 kHz in 8-bit mode with dead-time-free readout.
• Minimum detectable energy of 4.3 ± 0.3 keV, with low equivalent noise charge (ENC) and threshold dispersion.
• Energy calibration stability with temperature (< 0.5% °C⁻¹).

Conclusions:

• The MYTHEN III detector offers substantial performance improvements for synchrotron radiation applications.
• Its enhanced capabilities, particularly in count rate and speed, benefit time-resolved powder diffraction.
• The detector represents a significant advancement in microstrip detector technology for materials science.