A physics based machine learning model to characterize room temperature semiconductor detectors in 3D.

Room temperature semiconductor radiation detectors (RTSD) for X-ray and -ray detection are vital tools for medical imaging, astrophysics and other applications. CdZnTe (CZT) has been the main RTSD for more than three decades with desired detection properties. In a typical pixelated configuration, CZT have electrodes on opposite ends.

Identifying Defects without Knowledge in a Room-Temperature Semiconductor Detector Using Physics Inspired Machine Learning Model.

Room-temperature semiconductor radiation detectors (RTSD) such as CdZnTe are popular in Computed Tomography (CT) imaging and other applications. Transport properties and material defects with respect to electron and hole transport often need to be characterized, which is a labor intensive process. However, these defects often vary from one RTSD to another and are not known during characterization of the material.

Learning-based physical models of room-temperature semiconductor detectors with reduced data.

Room-temperature semiconductor radiation detectors (RTSD) have broad applications in medical imaging, homeland security, astrophysics and others. RTSDs such as CdZnTe, CdTe are often pixelated, and characterization of these detectors at micron level can benefit 3-D event reconstruction at sub-pixel level. Material defects alongwith electron and hole charge transport properties need to be characterized which requires several experimental setups and is labor intensive.

Oxidation of the perchlorotriphenylmethyl radical to the carbocation, and its unique abrupt reversion.

A solution of AlCl(3) in CH(2)Cl(2) reacts slowly, at room temperature, with perchlorotriphenylmethyl radical (PTM(*)), an inert carbon free radical, to give perchlorotriphenylmethyl cation (PTM(+)) quantitatively. However, by gradual addition of CH(2)Cl(2) into the resulting solution a point is reached where the PTM(+) reverts to PTM(*) instantaneously and quantitatively. A mechanism for this exceptional phenomenon is suggested.

1,1',3,3',6,6',8,8'-Octachloro-9,9'-bifluorenylidene and perchloro-9,9'-bifluorenylidene, two exceedingly twisted ethylenes.

The syntheses of 1,1',3,3',6,6',8,8'-octachloro-9,9'-bifluorenylidene (1), its precursors, and the byproduct 3,3',5,5'-tetrachloro-4-(trichloromethyl)biphenyl (5) are described. Accurate structural X-ray data on 1 and on perchloro-9,9'-bifluorenylidene (2) are reported and discussed. Because of chlorine overcrowding, the dihedral angles between their two identical fluorenylidene moieties are abnormally large, the central-ethylene twist angles being 55 and 66 degrees, respectively.