The prototype DynamiX camera system - a high-frame-rate high-dynamic-range hard X-ray integrating detector for...

Area of Science:

• X-ray detector technology
• Materials science
• Semiconductor device physics

Background:

• Fourth-generation synchrotrons, like Diamond-II, offer 10-100x flux increases, demanding detectors with high frame rates and dynamic ranges.
• High-Z sensor materials are crucial for exploiting high X-ray energies.
• Existing detector technologies may not meet the stringent requirements of next-generation light sources.

Purpose of the Study:

• To develop and evaluate DynamiX, a novel test structure for a two-stage charge cancellation circuit.
• To assess the performance of a hybrid detector system comprising a CMOS readout chip and high-flux cadmium zinc telluride (HF-CdZnTe) sensor.
• To validate the detector's capability to handle the extreme photon fluxes and energies from advanced synchrotrons.

Main Methods:

• Designed and fabricated a 16x16 pixel CMOS test structure (DynamiX) with a two-stage charge cancellation circuit on a 65nm process.
• Hybridized the CMOS chip with a 2mm thick HF-CdZnTe sensor.
• Utilized the Diamond Light Source (DLS) B16 Test Beamline with monochromatic and polychromatic X-ray beams for performance evaluation.
• Measured single-photon noise, detector linearity under varying flux conditions, and imaging capabilities at high frame rates.

Main Results:

• The DynamiX circuit demonstrated a dynamic range from single photons to over 9000 photons per pixel per frame (10^11-10^12 photons/s/mm^2) at 20 keV.
• Achieved a single-photon noise performance of sigma = 5.7 +/- 0.1 keV, enabling accurate calibration.
• Measured excellent linearity, with RMS linearity of 6.2% up to ~10^9 photons/s/mm^2 and 3.2% at ~3x10^10 photons/s/mm^2 (20 keV equivalent).
• Demonstrated high-speed imaging at 534,000 frames per second.

Conclusions:

• The DynamiX test structure and its hybrid detector system are well-suited for next-generation high-flux synchrotron applications.
• The novel charge cancellation circuit effectively addresses the challenges posed by increased photon flux and energy.
• The demonstrated performance metrics pave the way for advanced X-ray imaging and analysis at future light sources.