Abstract-DIII-D has four neutral beam lines (NB). Each of these beam lines has two ion sources, each of which injects up to

An efficient sample pretreatment/introduction technique for the inductively coupled plasma atomic emission spectrometry (ICP-AES) using ion exchange for analyte preconcentration and matrix separation and laser ablation sampling for sample introduction has been developed. Ammonium pyrrolidine dithiocarbamate (APDC)-polystyrene films are coated on glass plates for analyte preconcentration. Repetitive laser ablation sampling of the polymer film removes the ion-exchanged metal ions from the polymer film as fine particles for sample introduction into the ICP. After immersing the sample probe in a sample solution for 5 min, the ICP emission intensity for laser ablation of the polymer film is a few times larger than that after solution nebulization. The sample probe removes only a small fraction of the sample solution and, therefore, in principle, does not disturb the original solution significantly. Single-pulse laser ablation of the polymer film shows that the ion-exchanged metal ion concentration in the film reduces exponentially with the depth of the polymer film. Ion exchange to the polymer film is probably limited by the rate of metal ion diffusion into the film. Calibration curves for Cu, Hg, Pb, and Zn show linear dynamic range of ∼1-2 orders of magnitude. The linear dynamic range for Cu increases to >3 orders of magnitude when using Pb as an internal standard. RSD of the ICP emission intensity is ∼8%.

Experimental designs for a solar domestic hot water storage system were built in efforts to maximize thermal stratification within the tank. A stratified thermal store has been shown by prior literature to maximize temperature of the hot water drawn from the tank and simultaneously minimize collector inlet temperature required for effective heat transfer from the solar panels, thereby improving the annual performance of domestic solar hot water heating systems (DSHWH) by 30–60%. Our design incorporates partitions, thermal diodes, and a coiled heat exchanger enclosed in an annulus. The thermal diodes are passive devices that promote natural convection currents of hot water upward, while inhibiting reverse flow and mixing. Several variations of heat exchanger coils, diodes and partitions were simulated using ansys Computational Fluid Dynamics, and benchmarked using experimental data. The results revealed that the optimum design incorporated two partitions separated by a specific distance with four diodes for each partition. In addition, it was discovered that varying the length and diameter of the thermal diodes greatly affected the temperature distribution. The thermal diodes and partitions were used to maintain stratification for long periods of time by facilitating natural convective currents and taking advantage of the buoyancy effect. The results of the experiment and simulations proved that incorporating these elements into the design can greatly improve the thermal performance and temperature stratification of a domestic hot water storage tank.

The Accelerator Production of Tritium (APT) project will require up to 244 1-MW klystrons to provide radio frequency (RF) power for acceleration of a 100-mA proton beam. A major source of heat in the klystron gallery and the accelerator tunnel will be the RF waveguides, which conduct the RF power from the klystrons to the linac. Each waveguide is estimated to dissipate 11 kW of heat in the gallery and 17.5 kW in the tunnel. Base-case design called for conditioned-air cooling (to 104°F) of the tunnel space, with waveguide cooling by forced external convection. For more uniform and efficient waveguide cooling, several other techniques have been investigated, including water-cooling, cooling by nitrogen purging, and direct cooling of the waveguides by using them as air conditioning "ducts." Models were created simulating the last technique. This paper will report on measurements to be made on the Low Energy Demonstration Accelerator (LEDA) at the Los Alamos National Laboratory (LANL) based on these models.

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