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Semiconductor Sensors for XRD Imaging
Published in Joel Greenberg, Krzysztof Iniewski, X-Ray Diffraction Imaging, 2018
Krzysztof Iniewski, Adam Grosser
For diffraction and imaging applications, the direct conversion detectors are typically pixelated. When a photon strikes a certain pixel, a small charge is generated that must be sensed and processed. Over the past decade, this is often done with an Application-Specific Integrated Circuit (ASIC) that is directly attached to the CZT detector. Modern integrated circuit technology makes it economically feasible for each pixel to have its own low-noise electronics, creating what are known as hybrid pixel detector readout ASICs. The block diagram of the electronics for each pixel or channel is shown below in Figure 2.5. Chapter 3 of this book is entirely devoted to issues related to the readout ASIC electronics.
Photon-Counting Detectors for X-ray Imaging
Published in Paolo Russo, Handbook of X-ray Imaging, 2017
A photon counting hybrid pixel detector is a two-dimensional semiconductor array of pixelated anodes, which act as microscopic sensitive elements, namely pixels. Each sensitive element is connected to its individual readout electronic chain, provided by an application-specific integrated circuit (ASIC). A hybrid pixel detector consists of two superimposed layers. The top layer is the detecting material or sensor, in which X-rays can interact and their interaction is detected. The bottom layer is the readout electronics, and defines the segmentation and pixel pitch of the PCD. Sensor material and readout electronics are processed on two different substrates, and are electrically connected via the so-called bump-bonding and flip-chip techniques, realized by placing a drop (with a diameter in the order of 10–20 μm) of solder material (e.g., In, PbSn, Au) between two metal pads attached to sensor and ASIC. Each pixel of a hybrid pixel detector needs individual bump-bonding. A cross-sectional view of a hybrid pixel detector is shown in Figure 13.1, comprising a pixelated semiconductor sensor and a readout ASIC (Medipix2 chip). Each pixel cell of the readout ASIC features a complete signal processing cell. The readout of the processed digital signal from each individual pixel is driven by dedicated circuits placed at the chip periphery. When radiation quanta deposit their energy in a semiconductor detector material, e-h pairs are created as a result of ionization. Free electrons and holes are separated in the detection material by an externally-applied electric field. As a result of this, charge carriers drift and diffuse towards their respective pixel electrode and possibly their neighbors. This electric signal, proportional to the number of electron-hole pairs generated in the sensor volume, is then processed by the pixel readout electronics.
Application Specific Integrated Circuits for Direct X-Ray and Gamma-Ray Conversion in Security Applications
Published in Choi Jung Han, Iniewski Krzysztof, High-Speed and Lower Power Technologies, 2018
Krzysztof Iniewski, Chris Siu, Adam Grosser
Signal processing of the charge generated within the sensor is typically done with an Application Specific Integrated Circuit (ASIC) that is directly attached to the semiconductor detector. Modern integrated circuit technology makes it economically feasible for each pixel to have its own low-noise electronics, creating what are known as hybrid pixel detector readout ASICs.
Pluronic-based lamellar phases: influence of polymer architecture on bilayer bending elasticity
Published in Molecular Physics, 2021
Sören Großkopf, Peter Fouquet, Lars Wiehemeier, Thomas Hellweg
Small angle x-ray scattering (SAXS) experiments were performed at 20 C on an in-house SAXS/WAXS system (XEUSS, Xenocs, Sassenage, France) with a CuK source ( Å, GeniX Ultra low divergence, Xenocs, Sassenage, France) and a Pilatus 300 k hybrid pixel detector (Dectris, Baden Deattwil, Switzerland). The covered q range is 0.02 to 0.2 Å. The data were analysed using the Foxtrot software (Version 3.3.4, G. Viguier, R. Girardot). The sample scattering was normalised with respect to incident intensity, sample thickness, measuring time, transmission and background. The scattered intensity was brought to absolute scale using glassy carbon (type 2, sample P11[21]) as standard. In SAXS experiments, the scattered intensity depends on the number of particles N, the incident intensity , the scattering volume of the sample V, the electron density difference , on the particle form factor P(q), and the structure factor S(q). The experimental data were treated using the software GIFT of the PCG software package provided by O. Glatter[22, 23].
Electrospun PCL-protein scaffolds coated by pyrrole plasma polymerization
Published in Journal of Biomaterials Science, Polymer Edition, 2019
Yeyzon Cruz, Efrén Muñoz, E. Y. Gomez-Pachón, Juan Morales-Corona, Jesús Olayo-Lortia, Roberto Olayo, Roberto Olayo-Valles
The morphology of the scaffolds was characterized with a high-resolution scanning electron microscope (SEM, Jeol JSM-7600F) with a field emission source. The diameter of the fibers was determined using the ImageJ software (NIH), and histograms and lognormal distribution fits were performed with the Igor Pro software package (version 6.37, Wavemetrics). Chemical characterization was performed in a Fourier transform infrared (FTIR) spectrometer (SpectrumG, Perkin-Elmer) equipped with an attenuated total reflection accessory. The crystalline structure of the samples was studied by wide-angle (WAXS) and small-angle X-ray scattering (SAXS) in a Xeuss (Xenocs) instrument equipped with a Cu Kα source (Genix3D) and a hybrid pixel detector (Pilatus 300 K, Dectris). Thermogravimetric analysis was done with a Pyris 1 TGA balance (Perkin Elmer) running in nitrogen atmosphere. The heating ramp was 10 °C/min, from 25 to 700 °C. Differential scanning calorimetry (DSC) was performed with a 2920 MDSC V2.6A (TA Instruments) using nitrogen as purge gas (flowrate 50 mL/min). Samples were analyzed by a heat/cool/heat method in a range of 20 °C to 250 °C at a 10 °C/min heating and cooling rate. The degree of crystallinity was calculated according to Equation 1: where is the heat of fusion measured by DSC and is the heat of fusion of 100% crystalline PCL (139.5 J/g) [14].