PSICHE (Pressure, Structure and Imaging by Contrast at High Energy) is the high-energy beam line of the SOLEIL synchrotron. The beam line is designed to study samples at extreme pressures, using diffraction, and to perform imaging and tomography for materials science and other diverse applications. This paper presents the tomograph and the use of the beam line for imaging, with emphasis on developments made with respect to existing instruments. Of particular note are the high load capacity rotation stage with free central aperture for installing large or complex samples and sample environments, x-ray mirror and filter optics for pink beam imaging, and multiple options for combining imaging and diffraction measurement. We describe how x-ray imaging techniques have been integrated into high-pressure experiments. The design and the specifications of the beam line are described, and several case studies drawn from the first user experiments are presented.

The impressive progress in the performance of synchrotron radiation sources is nowadays driven by the so-called `ultimate storage ring' projects which promise an unprecedented improvement in brightness. Progress on the detector side has not always been at the same pace, especially as far as soft X-ray 2D detectors are concerned. While the most commonly used detectors are still based on microchannel plates or CCD technology, recent developments of CMOS (complementary metal oxide semiconductor)-type detectors will play an ever more important role as 2D detectors in the soft X-ray range. This paper describes the capabilities and performance of a camera equipped with a newly commercialized backside-illuminated scientific CMOS (sCMOS-BSI) sensor, integrated in a vacuum environment, for soft X-ray experiments at synchrotron sources. The 4 Mpixel sensor reaches a frame rate of up to 48 frames s−1 while matching the requirements for X-ray experiments in terms of high-intensity linearity (>98%), good spatial homogeneity (<1%), high charge capacity (up to 80 ke−), and low readout noise (down to 2 e− r.m.s.) and dark current (3 e− per second per pixel). Performance evaluations in the soft X-ray range have been carried out at the METROLOGIE beamline of the SOLEIL synchrotron. The quantum efficiency, spatial resolution (24 line-pairs mm−1), energy resolution (<100 eV) and radiation damage versus the X-ray dose (<600 Gy) have been measured in the energy range from 40 to 2000 eV. In order to illustrate the capabilities of this new sCMOS-BSI sensor, several experiments have been performed at the SEXTANTS and HERMES soft X-ray beamlines of the SOLEIL synchrotron: acquisition of a coherent diffraction pattern from a pinhole at 186 eV, a scattering experiment from a nanostructured Co/Cu multilayer at 767 eV and ptychographic imaging in transmission at 706 eV.

Ptychography is a coherent diffraction imaging technique that measures diffraction patterns at many overlapping points on a sample and then uses an algorithm to reconstruct amplitude and phase images of the object and probe. Here, we report imaging, spectroscopy and linear dichroism ptychographic measurements at the carbon K-edge. This progress was achieved with a new generation of scientific Complementary Metal Oxide Semiconductor (sCMOS) X-ray cameras with an uncoated image sensor which has fast image transfer and high quantum efficiency at the carbon K-edge. Reconstructed amplitude and phase contrast images, C 1s spectral stacks, and X-ray linear dichroism of carbon nanotubes at the carbon K-edge were measured with ptychography. Ptychography and conventional Scanning Transmission X-ray Microscopy (STXM) are compared using results acquired from the same area. Relative to STXM, ptychography provides both improved spatial resolution and improved image quality. We used defocus ptychography, with an X-ray beam spot size of 1.0 micron, in order to reduce radiation damage and carbon deposition. Comparable spatial resolution was achieved to that of ptychography performed with a focused beam. Ptychography at the carbon K-edge offers unique opportunities to perform high resolution spectromicroscopy on organic materials important in medicine, biology, environmental science and energy materials.

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A commercial scientific camera has been adapted and characterized at the SOLEIL Synchrotron with the aim to improve the acquisition capabilities on the soft X-ray coherent scattering experimental station at SEXTANTS beamline. This device is equipped by the last generation of back side illuminated scientific CMOS (BSI-sCMOS) of 2048 by 2048 pixels of 11 m² able to acquire low noise images with a frame rate up to 48 Hz. The camera's performance measurements have been done and shows a good level of readout noise, a large full-well capacity, a medium dark current and a good homogeneity, respectively, 1.6 e-rms (in High Gain mode), 80 000 e-(in Low Gain mode), < 5 e-/pixel/s and ~ 1%. The quantum efficiency (QE) measurement has been performed at the soft x-ray branch of the METROLOGIE beamline and gives a relatively good agreement with the expected theoretical values. Finally, the demonstration of the camera's efficiency and of the gain in useful time measurement related to the high frame rate have been performed with a series of Airy patterns images compared with an image recorded using the standard BSI-CDD already in operation at the SEXTANTS beamline.