Design and test results of scientific x-ray CMOS cameras

Abstract

In recent years, scientific CMOS (sCMOS) sensors have found increasing applications to X-ray detection, including Xray astronomical observations. In order to examine the performance of sCMOS sensors, we have developed X-ray cameras based on sCMOS sensors. Two cameras, CNX22 and CNX 66, have been developed using sCMOS sensors with a photosensitive area of 2 cm  2 cm and 6 cm  6 cm, respectively. The designs of the cameras are presented in this paper. The CNX22 camera has a frame rate of 48 fps, whereas CNX66 has a frame rate of currently 20 fps, that can be boosted to 100 fps in the future. The operating temperature of the sCMOS sensor can reach to -20C for CNX22 and -30C for CNX66 with a peltier cooler device. In addition to the commonly used mode of saving original images, the cameras provide a mode of real-time extraction of X-ray events and storage their information, which significantly reduces the requirement for data storage and offline analysis work. For both cameras, the energy resolutions can reach less than 200 eV at 5.9 keV using single-pixel events. These cameras are suitable for X-ray spectroscopy applications in laboratories and calibration for the space X-ray telescopes.

Investigating causal relationships between the gut microbiota and allergic diseases: A mendelian randomization study

“…In addition, Begley et al (2018) demonstrated that compared with normal children, the relative abundance of Bifidobacterium declined significantly in the gut bacteria community of children at high risk of asthma. Notably, certain strains of Bifidobacterium had been illustrated to alleviate asthma via inhibiting Th1/Th2 activation (Wang et al, 2020). The inconsistency between our causal estimation and the results of clinical trials as stated above might be traceable to the following reasons.…”

“…For example, the colonization of Bacteroides fragilis was identified to show a positive correlation with the prevalence of asthma during early childhood development. And a relative abundance of Ruminococcaceae and Bifidobacterium lead to an increase asthma and eczema in infants (Vael et al, 2008;Begley et al, 2018;Berni Canani et al, 2019;Wang et al, 2020;Zhu et al, 2020). However, the causal relationship between gut microbiota composition and allergic disease remains elusive.…”

Relativistic Semistochastic Heat-Bath Configuration Interaction

“…The SHCI calculations are performed using the ZSHCI module of the Dice code by the authors . The input and output for all calculations can be accessed from a public repository . All the SHCI calculations use an ϵ 2 value of 10 –10 a.u., and the stochastic errors are converged to 5 × 10 –6 a.u.…”

“…The X2CAMF Hamiltonian is computed using the X2CAMF package by Zhang . The X2CAMF Hartree–Fock (HF) calculations are performed through the socutils code by one of the authors . The SHCI calculations are performed using the ZSHCI module of the Dice code by the authors .…”

Investigating the image lag of a scientific CMOS sensor in X-ray detection

“…These X-rays are then recorded by a camera at the bottom. The camera is made of a GSENSE1516BSI sCMOS sensor, readout electronics, and temperature control structures [24]. The camera has two working modes: the image mode, in which raw images are read out and saved into a disk directly; and the event mode, in which X-ray events are extracted from raw images in real time and only such events are saved into the disk.…”