X-Ray sCMOS Camera Detecting EUV and Soft X-Ray Photons
High Frame Rate, Low Noise, Direct Detection Imaging of EUV and Soft X-Rays
The Sydor Wraith X-Ray Detector is a scientific sCMOS based camera sensitive to wavelengths from EUV to soft x-ray. It is a direct detector meaning soft x-ray and EUV imaging applications can benefit from the improved Quantum Efficiency (QE) when photons are directly converted to charge in the detector Si layer; as opposed to approaches using scintillators and indirect detection.
The Wraith sCMOS camera is further optimized for QE by using a back illuminated sCMOS chip that has been re-configured for ultimate sensitivity to photons in the EUV to soft x-ray wavelengths. The Quantum Efficiency of the back illuminated detector is enhanced for energies below 500eV with no coatings present on the light sensitive face.
The sCMOS architecture enables significant frame rates of up to 48Hz at full resolution while maintaining noise levels below 4e-.
EUV and Soft X-Ray Detection
For EUV Ptychography studies the dynamic range is also impressive with full well capacity of 77,000 e-. For other application when a full square active area is not required, such as EUV and soft x-ray Spectroscopy, speed can be further increased to reach frame rates approaching 1 KHz.
The system is specifically configured for soft x-ray and EUV imaging plus soft x-ray and EUV spectroscopy applications which are usually operating in vacuum. The design maintains much of the electronics outside of the vacuum environment, with just the chip protruding in vacuum on a custom UHV compatible carrier board. This approach reduces the risk of outgassing from the X-Ray detector and removes the risk of contamination of any samples, something which is critical for soft x-ray spectroscopy in around the ‘water window’ (250eV – 550eV).
Why EUV sCMOS?
Until now the technology of choice for EUV and soft x-ray imaging has been CCDs which offered low read noise capabilities, often required when trying to detect the relatively weak signals produced by ‘low energy’ EUV and soft x-ray photons. The low noise capabilities of CCDs were often tied to slow read out rates, which meant low frame rates and poor effective duty cycles for the detectors. Experiments such as EUV Ptychography and soft x-ray Ptychography require a large number of images and as such have been severely limited by the slow frame rates of CCDs. Until now the only option available has been a customized version of a CCD such as the Sydor Fast CCD which implemented a large number of readouts on each side of the chip to increase speed. This device is still an excellent choice for the most demanding configurations, offering frame rates up to 120Hz. However, recent development in sCMOS chips have given rise to the Sydor Wraith sCMOS camera, based on a back illuminated sCMOS architecture that is modified to be sensitive to the low energy photons in EUV and soft x-ray wavelengths.
The sCMOS architecture incorporates more A/D’s on chip with the benefits of increased speed and frame rates up to 48Hz, while maintaining low noise. The architecture enhances the simplicity of the system leading to reduced cost and complexity. With the new modified EUV sCMOS technology the Sydor Wraith X-Ray Detector aims to deliver high performance EUV and soft x-ray imaging in combination with system simplicity and affordability.
Wraith X-Ray sCMOS Camera Specifications
- Sensor Material: Uncoated Si
- Sensor Format: 2048 x 2048 pixels
- Pixel Pitch: 11 μm
- Full Well Capacity: 80,000 e- (HDR)
- Read Noise: 1.6 e- or 2.6 e- (setting dependent)
- Dark Current: 0.5 e-/pix/s
- Full Res. Frame Rate: 24Hz (HDR) or 48 Hz (STD)
- Minimum Integration Time: 21 us
- Spectral Range: EUV to 1 keV
- Shutter: Rolling
- Vacuum Compatibility: 10-9mbar
- Serviceability: User exchangeable chips
- User Interface: EPICS/Tango and/or proprietary Sydor Control Interface
Sydor Wraith sCMOS Camera Customizations
With the Sydor Wraith platform as a baseline Sydor is able to offer customized configurations with examples including tiled or tilted chips, different pixel sizes, different active areas and more.