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Use of multiple 4$pi$ radiation sources for quasi-uniform irradiation of square surfaces

Description: The question of distance and location of multiple 4 pi radiation sources from square planar target surfaces is addressed, with the constraint that the surface be irradiated with 80% uniformity. Results of computer calculations are presented, giving source location coordinates for optimum use of the sources under the uniformity constraint. (auth)
Date: November 1, 1973
Creator: Clark, R.W. & Freiwald, D.A.
Partner: UNT Libraries Government Documents Department

Quantitative sequential imaging of radionuclide distribution using the whole-body scanner and the gamma camera: absolute accuracy and aspects of three-dimensional reconstruction

Description: From eleventh international annual meeting of the German Society of Nuclear Medicine; Athens, Greece (24 Sep 1973). Progress in quantitating the distribution of isotope within organs on sequential images of the whole body using the whole-body scanner, and on techniques of reconstructing the three- dimensional distribution from multiple gamma-camera views using a variety of different algorithms is reported. The following variables are involved in the precise quantitation of the amount of radiopharmaceuticals in regions of the body: geometry effect, patient thickness, thickness and homogeneity of isotope distribution, source position, one photon attenuation coefficient. The whole- body scanner used consists of 64 detectors distributed as four rows of 16 detectors with a diagonal offset to give good resolution and adequate collimation between the single 3.2-cm diameter by 3.8-cm thick sodium iodide (TI) crystals. The patient is positioned on a bed that is moved over the detector array and pulse-height selection is used to separate pulses between different isotopes. The scan durations can vary from 0.75 minute to hours. (auth)
Date: September 1, 1973
Creator: Budinger, T.F.; Gullberg, G.T.; Nohr, M.L.; McRae, J. & Anger, H.O.
Partner: UNT Libraries Government Documents Department

Geometry of some metal halides

Description: Thesis. Two polarizable ion models are developed to describe the gas phase of metal dihalide molecules. Both models use electrostatic and repulsive interactions to predict molecular geometries and molecular constants. The first model is applied to the dihalides of the alkaline earths, group II-b metals, transition metals, group IV-a metals, and europium. In addition to the molecular geometry, bending frequencies are derived for most of these molecules. The second or linear'' model is applied to the alkaline eanth dihalides; equilibrium internuclear bond lengths, stretching force constants, and stretching frequencies are determined. (LK)
Date: July 1, 1973
Creator: Yarnell, P.A.
Partner: UNT Libraries Government Documents Department