High-dynamic-range coherent diffractive imaging: ptychography using the mixed-mode pixel array detector.

Area of Science:

• X-ray Microscopy
• Diffractive Imaging
• Detector Technology

Background:

• Coherent (X-ray) diffractive imaging (CDI) offers high-resolution imaging without objective lenses, but requires high dynamic range data.
• Collecting sufficient dynamic range data is crucial for quantitative and high-resolution imaging in CDI.

Purpose of the Study:

• To demonstrate the potential of the Mixed-Mode Pixel Array Detector (MM-PAD) for hard X-ray ptychographic coherent diffractive imaging.
• To showcase the detector's capability in handling very wide dynamic range diffraction data.

Main Methods:

• Hard X-ray ptychographic coherent diffractive imaging was performed at the PETRA III synchrotron.
• Utilized the Mixed-Mode Pixel Array Detector (MM-PAD) capable of single photon detection and high framing rates (1 kHz).
• Ptychographic reconstruction was achieved with high peak focal intensity (1 × 10(10) photons µm⁻² s⁻¹) without a beam stop.

Main Results:

• The MM-PAD successfully handled high dynamic range diffraction data, exceeding 1 × 10⁸ 8-keV photons pixel⁻¹ s⁻¹.
• High-resolution imaging was achieved with a peak focal intensity of approximately 1 × 10¹⁰ photons µm⁻² s⁻¹.
• Reconstruction included methods for non-sensitive detector regions, extending the effective detector area.

Conclusions:

• The MM-PAD is a promising detector for advanced X-ray microscopy techniques like ptychographic CDI.
• The detector's wide dynamic range and high speed facilitate high-resolution, quantitative imaging in challenging X-ray experiments.
• The developed reconstruction methods enhance the utility of the MM-PAD by addressing detector limitations.