A 5-μm pitch charge-coupled device optimized for resonant inelastic soft X-ray scattering

Area of Science:

• X-ray instrumentation
• Detector physics
• Materials science

Background:

• Advancements in X-ray spectroscopy require detectors with high efficiency and resolution.
• Existing charge-coupled devices (CCDs) may have limitations in specific applications like Resonant Inelastic X-ray Scattering (RIXS).

Purpose of the Study:

• To develop and characterize a novel CCD optimized for RIXS.
• To evaluate the performance of the new CCD compared to existing technologies.

Main Methods:

• Fabrication of a fully depleted, back-illuminated CCD with 5 μm × 45 μm pixels on high-resistivity silicon.
• Testing the CCD at the Advanced Light Source (ALS) RIXS beamline.
• Performance evaluation using a C K-edge X-ray beam on a graphite sample.

Main Results:

• The 1.5-megapixel CCD demonstrates high efficiency for soft to hard X-rays (>8 keV).
• Achieved quantum efficiency >75% from 200 eV to 1 keV.
• Readout noise of 3-6 electrons and a point spread function of 4.0 μm ± 0.2 μm for soft X-rays.

Conclusions:

• The developed CCD offers superior spectroscopic performance for RIXS, especially for spectrometers with limited arm lengths.
• The detector's design and performance represent a significant improvement over current commercial cameras for specific X-ray applications.