The increasing availability of short lived gamma and positron emitting isotopes, coupled with the importance of dynamical studies and better imaging, has generated the need for an improved {gamma}-ray camera. The authors discuss a new type of {gamma}-ray camera which makes use of electron avalanches in liquid xenon. A configuration currently under development is shown in Figure 1. The successful operation of a liquid xenon proportional counter was recently reported. The liquid xenon camera promises better spatial resolution and higher counting rate than the existing NaI(Tl) scintillation camera. The spatial resolution for {gamma} rays is in principle limited only by the range of photoelectrons in liquid xenon, which is < 0.2 mm for energies < 1 MeV. A counting rate of 10{sup 6} C/s or more appears possible. As a result of the better resolution and high counting rate capability, the definition of the picture is improved. In addition, the high counting rate capability makes possible dynamic studies which were previously unfeasible. Although they expect the energy resolution with liquid xenon to be superior to that of NaI, the preliminary measurements show 17% FWHM for 279 keV {gamma}'s. Improvements are expected by using better geometry and smoother wire.

Conceptual designs for 6- and 18-subassembly casks are presented. The casks are intended for transport of LMFBR spent fuel which has decayed a minimum of 30 days. These casks use sodium as the primary coolant, an auxiliary shield coolant system in normal operation, heavy steel members as both gamma shield and structure, and a eutectic mixture of LiOH and NaOH as a neutron shield. The analysis indicates that there will be no leakage of coolant or fission products under normal or hypothetical accident conditions.

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A system is described for use in homogenizing poly- and single-crystal metal samples at temperatures up to about 1300/sup 0/C. The furnace tube may be evacuated to a dynamic vacuum of 10/sup -3/ to 10/sup -4/ torr. A provision exists for pushing the sample from the hot zone into a zone the walls of which are at room temperature.

High purity nitrate esters of the pentaerythritols can be successfully synthesized from correspondingly high purity reagents. The latter are not commercially available, but may be purified through molecular distillation and/or fractional crystallization from xylene. The isolated products are ultimately saponified to reagents of high purity. The nitration of high purity pentaerythritols using 97-100% nitric acid proceeds smoothly resulting in yields of the corresponding nitrate esters which are nearly quantitative. Thin layer chromatography (TLC) indicates numerous satellite impurities present in all the pentaerythritol-tetranitrate (PETN) homologs with the exception of ultrapure PETN itself. Separation and isolation of these contaminants, from a high impurity concentrate, was achieved by liquid chromatography. IR spectra of these components suggests these compounds are the various homologs and pentaerythryl ethers with a mixture of hydroxyl and nitrate functional groups.