The ePix10k 2-megapixel hard X-ray detector at LCLS

Abstract

The ePix10ka2M (ePix10k) is a new large area detector specifically developed for X-ray free-electron laser (XFEL) applications. The hybrid pixel detector was developed at SLAC to provide a hard X-ray area detector with a high dynamic range, running at the 120 Hz repetition rate of the Linac Coherent Light Source (LCLS). The ePix10k consists of 16 modules, each with 352 × 384 pixels of 100 µm × 100 µm distributed on four ASICs, resulting in a 2.16 megapixel detector, with a 16.5 cm × 16.5 cm active area and ∼80% coverage. The high dynamic range is achieved with three distinct gain settings (low, medium, high) as well as two auto-ranging modes (high-to-low and medium-to-low). Here the three fixed gain modes are evaluated. The resulting dynamic range (from single photon counting to 10000 photons pixel−1 pulse−1 at 8 keV) makes it suitable for a large number of different XFEL experiments. The ePix10k replaces the large CSPAD in operation since 2011. The dimensions of the two detectors are similar, making the upgrade from CSPAD to ePix10k straightforward for most setups, with the ePix10k improving on experimental performance. The SLAC-developed ePix cameras all utilize a similar platform, are tailored to target different experimental conditions and are designed to provide an upgrade path for future high-repetition-rate XFELs. Here the first measurements on this new ePix10k detector are presented and the performance under typical XFEL conditions evaluated during an LCLS X-ray diffuse scattering experiment measuring the 9.5 keV X-ray photons scattered from a thin liquid jet.

Near-physiological-temperature serial crystallography reveals conformations of SARS-CoV-2 main protease active site for improved drug repurposing

“…The LCLS X-ray beam with a vertically polarized pulse with duration of 30 fs was focused using compound refractive beryllium lenses to a beam size of ∼6 × 6 μm full width at half maximum (FWHM) at a pulse energy of 0.8 mJ, a photon energy of 9.8 keV (1.25 Å) and a repetition rate of 120 Hz. OM monitor ( Mariani et al., 2016 ) and PSOCAKE ( Damiani et al., 2016 ; Thayer et al, 2017 ) were used to monitor crystal hit rates, analyze the gain switching modes and determine the initial diffraction geometry of the new ePix10k2M detector ( van Driel et al., 2020 ). A total of 1,163,413 detector frames were collected in 2h47m7s continuously with the new from native (construct-1) Mpro microcrystals.…”

“…The diffraction patterns were collected at the MFX instrument at the LCLS using the ePix10k2M detector ( van Driel et al., 2020 ). The raw data images were subjected to detector corrections with CHEETAH ( Barty et al., 2014 ), as well as for hit finding based on Bragg reflections.…”

“…In this work, we ascertain some conformational dynamics of Mpro via high-throughput serial crystallography using the macromolecular femtosecond crystallography (MFX) instrument from the Linac Coherent Light Source (LCLS), which provides ultrafast and ultrabright X-ray pulses allowing data collection without secondary radiation damage at ambient temperature ( Sierra et al., 2019 ; Blaj et al, 2019 ; van Driel et al., 2020 ). Our structural data reveal the active site of SARS-CoV-2 Mpro with ambient-temperature radiation damage-free data and were used for subsequent in silico investigation of known Mpro inhibitors with the binding pocket residues.…”

Cooperative Allostery and Structural Dynamics of Streptavidin at Cryogenic- and Ambient-temperature

“…X-ray beam with a vertically polarized pulse with duration of 30 fs was focused using compound refractive beryllium lenses to a beam size of ∼6 × 6 μm full width at half maximum (FWHM) at a pulse energy of 0.8 mJ, a photon energy of 9.8 keV (1.25 Å) and a repetition rate of 120 Hz. OM monitor [51] and PSOCAKE [52, 53] were used to monitor crystal hit rates, analyze the gain switching modes and determine the initial diffraction geometry of the detector [54]. The detector distance was arranged as 18 mm, with an achievable resolution of 2.1 Å at the edge of the detector and 1.64 Å at the corner of the detector.…”

Near-Physiological-Temperature Serial Femtosecond X-ray Crystallography Reveals Novel Conformations of SARS-CoV-2 Main Protease Active Site for Improved Drug Repurposing

“…Linac Coherent Light Source (LCLS) with its ultrafast and ultrabright pulses enables outrunning secondary radiation damage. The updated high-throughput Macromolecular Femtosecond Crystallography (MFX) instrument of LCLS that is equipped with the new autoranging epix10k 2-megapixel (ePix10k2M) detector that provides a dynamic range of eleven thousand 8keV photons in fixed low gain mode to collect secondary radiation-damage-free structural data from Mpro microcrystals remotely at ambient-temperature (Sierra et al, 2019; Blaj et al, 2019; Van Driel et al, 2020).…”