Radiation imaging apparatus

A radiation imaging system using a charge multiplier and a position sensitive anode in the form of periodically arranged sets of interconnected anode regions for detecting the position of the centroid of a charge cloud arriving thereat from the charge multiplier. Various forms of improved position sensitive anodes having single plane electrode connections are disclosed. Various analog and digital signal processing systems are disclosed, including systems which use the fast response of microchannel plates, anodes and preamps to perform scintillation pulse height analysis digitally

Measurement of the tt̄W and tt̄Z production cross sections in pp collisions at √s = 8 TeV with the ATLAS detector

The production cross sections of top-quark pairs in association with massive vector bosons have been measured using data from pp collisions at s√ = 8 TeV. The dataset corresponds to an integrated luminosity of 20.3 fb−¹ collected by the ATLAS detector in 2012 at the LHC. Final states with two, three or four leptons are considered. A fit to the data considering the tt̄W and tt̄Z processes simultaneously yields a significance of 5.0σ (4.2σ) over the background-only hypothesis for tt¯Wtt¯W (tt̄Z) production. The measured cross sections are σtt̄W = 369 + 100−91 fb and σtt̄Z = 176 + 58−52 fb. The background-only hypothesis with neither tt̄W nor tt̄Z production is excluded at 7.1σ. All measurements are consistent with next-to-leading-order calculations for the tt̄W and tt̄Z processes

MULTIPURPOSE SCINTILLATION CAMERA

Photograph of fishing boats in a harborJapanese fishing boats in small harbor

MULTIPURPOSE SCINTILLATION CAMERA

The scintillation camera is a nonscanning instrument for displaying the distribution of radioactive isotopes. It can be used, for example, to show abnormalities in the thyroid gland with I-131, the size, shape and location of kidneys with Hg-203 Neohydrin or to locate brain tumors either with Hg-203 Neohydrin or with the new positron emitting agent, Ga-68 EDTA. For many applications, the scintillation camera has higher sensitivity than conventional isotope scanners, and will produce pictures in less time or with a smaller quantity of isotope present. Alternatively, it produces better pictures if the conventional dosage and exposure factors are retained. Because of the short exposure time, and because the scintillation camera is continuously sensitive to all areas within its field of view, it is well adapted to taking rapid sequences of still pictures or time-lapse motion pictures of subjects in which the distribution of radioactivity is changing. For example, time lapse pictures have been taken showing I-131 Rose Bengal Bengal being excreted from the liver of children with liver disease and of I-131 hippuran going through the kidneys of patients suspected of kidney disease