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Optimization of Data Recorded by Internal Reflectance Spectroscopy
Published in Patricia B. Coleman, Practical Sampling Techniques for INFRARED ANALYSIS, 2020
Senja V. Compton, David A. C. Compton
In ATR, a type of IRS, the sample is placed in contact against a special crystal, termed an internal reflectance element (IRE). The IRE is composed of a material with a high index of refraction, such as zinc selenide (ZnSe), thallium iodide-thallium bromide (KRS-5), or germanium (Ge). The infrared beam from the spectrometer is focused onto the beveled edge of an IRE by a set of mirrors, reflected, generally numerous times, through the crystal, and then directed to the detector by another set of mirrors.1,2,4–6
Reclaimed Wastewater Monitoring — Sampling and Analysis
Published in Donald R. Rowe, Isam Mohammed Abdel-Magid, Handbook of Wastewater Reclamation and Reuse, 2020
Donald R. Rowe, Isam Mohammed Abdel-Magid
For laboratory gamma radiation detection, crystals such as sodium iodide containing a trace of thallium iodide [Nal(TI)] or germanium diodes [Ge(Li)] are used. These crystals are connected to a photocell known as a photomultiplier tube. The crystals and photomultiplier are referred to as a scintillation detector. The basic scintillation system for detecting and identifying gamma radiation consists of a high-voltage supply, a preamplifier, and an N scaler. However, only a Nal and Ge(Li) detector coupled with a multichannel analyzer can provide energy spectra of the gamma rays and therefore verify the identity of a specific radionuclide.13,55
Materials Used for General Radiation Detection
Published in Alan Owens, Semiconductor Radiation Detectors, 2019
Thallium iodide selenide (Tl6I4Se) is a direct-gap material with a bandgap of 1.86 eV. It melts congruently at 432oC and crystallizes into a dense (7.4 g cm–3) tetragonal structure. Johnsen et al. [231] grew single crystalline material by a modified vertical Bridgman method. The resulting sample shows single-crystalline domains from which wafers were cut perpendicular to the growth direction. A detector was fabricated from a 6 × 4 × 2 mm3 single crystal diced from a wafer and Ti/Au contacts evaporated on to the top and bottom faces. From I-V measurements, the resistivity was found to be 4 × 1012 Ω-cm along the 〈001〉 crystallographic direction. The mobility–lifetime products were determined from photoconductivity measurements and found comparable to CdZnTe for electrons (μeτe = 7 × 10–3 cm2V–1) and an order of magnitude larger for holes (μhτh = 6 × 10–4 cm2V–1).
Study on selective surface black chromium-coated copper characteristics of a solar receiver at mid-temperature
Published in International Journal of Ambient Energy, 2021
K. Logesh, A. Vasudevan, K. Subramani, S. Kolappan
Moravec and Skogman explained antireflective coatings in solar collectors. This antireflective coating can also be obtained from very thin layers of two materials, such as thallium iodide and lead fluoride which have appropriately coordinated indices of refraction. Süzer, Kadirgan, and Söhmen (1999) studied the characterisation of Co and Cr-pigmented copper solar absorbers. They used a number of electro deposition methods to organise black cobalt together by depositing Co3O4. Noguchi et al. (1982) experimentally explained about ZrCx/Zr and Cr–CrOx films for practical solar-selective absorption systems and mentioned that agglomeration has been reserved at temperatures up to 800°C for one hour and the boundary of silver stability was accomplished at about 500°C.