Back-side illuminated scientific CMOS detector for soft X-ray beamlines The last CMOS sensors now rival the measured at the METROLOGIE beamline. The demonstration of performance of state-of-the-art photon its ability to be used at high flux undulator beamlines has been done by recording soft X-ray scattering from nanostructured detectors for optical applications, while thin film at the SEXTANTS beamline and imaging by Soft X-ray also operating at higher speeds and over a Ptychography at the HERMES beamline. wider dynamic range. In the UV and Soft CAMERA PERFORMANCES X-ray domains, the scientists lacked such performant 2D detector principally due to Two sCMOS-BSI GSENSE400 sensors have been evaluated. The first is mass produced for visible application (TVISB) and the very poor efficiency limited by the sensor the second is a pre-production prototype sensor without anti- processing. Recently, a new generation of reflected coating (no-ARC, called GP). The efficiency has been large Back-Side Illuminated scientific CMOS measured for an X-ray energy range of 30 eV to 2000 eV and sensors (sCMOS-BSI) has been developed compared with a theoretical model (Fig. 1). Our results show that the efficiency is sufficient with a maximum close to 90% and commercialized. One of this cost efficient obtained at 1000 eV for the TVISB and 600 eV for the GP, and competitive, the GSENSE400BSI has due to the different Epi-Si thicknesses. The spatial resolution measurement has been performed for 1500 eV and show a been implemented, characterized on the 10 % modulation transfer contrast reached around 24 lp/mm, METROLOGIE beamline from 30 eV to corresponding to a half-pitch resolution of 21 μm. The energy 2000 eV and its performances have been resolution is found to be around 80 eV fitting with the model for a total noise close to 6 e- rms. Also, the noise floor is reached for illustrated on SEXTANTS and HERMES energies below 200 eV. The radiation hardness evaluation has beamlines. been carried out for different energies and fluxes showing a limitation around 600 Gy before response degradation (especially The sCMOS-BSI GSENSE400 is the first large production a dark level evolution). sensor whose manufacturing process is compatible with soft X-ray applications. It is based on 2048 by 2048 pixels of 11 µm²EXPERIMENTAL RESULTS with two gains and a combined gain mode to achieve the High The sCMOS camera has been installed on the end-station of the Dynamic Range (HDR). The illumination on the back-side, the thinSEXTANTS beamline. A soft X-ray scattering pattern collected at silicon EPI and entrance window coating layer enable to obtain767 eV from rectangular dots lithographically carved in a Co/Cu a good efficiency over the entire low X-ray energy domain. Thesample has been successfully compared to the image acquired dynamic could reach 92 dB with a low readout noise (< 2 e- rms)using a CCD-BSI camera. The total measuring time is quite and a relatively large charge capacity (80 ke-). In addition, thedifferent in the two cases, 20 s for the sCMOS against 7 minutes sensor has a good spatial performance and respectable dark for the CCD. At the HERMES beamline, a new dedicated set-up current (/home/webapps/asp_fr/data/asp/publications/synchrotron-soleil/synchrotron-soleil-2020/soleil-highlights-2020-hd-ss-tc3 e-/s/pixel at -20°C). Compared to the CCD-BSI for soft X-ray ptychography has been implemented by replacing camera, its acquisition speed can reach 48 Hz for the standardthe 1D detector by the sCMOS camera. The capability of this gain and 24 Hz for the HDR mode which corresponds to a dead new set-up has been demonstrated in ptychography mode by time gain of about 100. As an example, the CCD installed at imaging magnetotactic bacteria at 706 eV. A region-of-interest the end-station [1] on SEXTANTS has a deadtime of 97.5% was selected on the sCMOS which allows reducing the total (0.1s of collection followed by 4 s of readout). A sCMOS acquisition time to 10 min. Fig. 2.a shows the low-resolution water cooled UHV compatible camera prototype based on the classical image obtained by image integration, while Fig. 2.b existing camera for optical application has been integrated [2].shows the reconstructed ptychography image from speckle The mechanical design and a dedicated Tango device have pattern image. This reconstruction allows bacterial with an been developed. The performance in term of efficiency, spatialaverage size of < 25 nm to be clearly observed, well beyond and energy resolutions and the radiation hardness have been the resolution of the zone plates used (outer ring width 50 nm). 82