Design of gridded sheet beam electron gun
A sheet beam gun with spoke grid is designed with EOS [1][2]. The results between with spoke grid and without spoke grid have been compared under the same wiggler magnetic field. When there is spoke grid, the electron beam will have a strong fluctuation in the narrow planar, but will not have great impact in the broad planar.
Theory and Design of Microwave-Tube Simulator Suite
The development of microwave-tube simulator suite (MTSS) is reported. MTSS is an integrated full-featured software package for microwave-tube analysis and design. It includes a friendly user-interface module and three physics simulators. Microwave-tube design environment is the user-interface module, which provides a powerful solid-modeling front end and graphical and computational postprocessing functionality. Electron optics simulator (EOS) is a fully 3-D finite-element design tool for microwave-tube electron guns and collectors. An EOS is used to design gridded guns, multibeam guns, and anisotropic collectors. A high-frequency circuit simulator is an advanced 3-D electromagnetic (EM) simulation tool for RF components, which has two solution methods based on a finite-integration technique and a finite-element method. Beam-wave interaction simulator (BWIS) is a design tool for electron beam and EM-wave interaction in microwave tubes. The 1-D, 2-D, and 3-D multifrequency nonlinear beam-wave interactions for helix traveling-wave tubes have been implemented in BWIS. The architecture, features, theory, and design of MTSS are presented.
Full-scale measurements of SO2 gas phase concentrations and slurry compositions in a wet flue gas desulphurisation spray absorber
Abstract Two measurement campaigns were carried out at ENERGI E2's Asnaes Power plant, unit 5. The unit has a capacity of 620 MW e and is equipped with a wet flue gas desulphurisation (FGD) plant employing a counter-current spray absorber with five spray levels. In the first campaign, the power plant was firing Orimulsion ® with 2.85 wt% S resulting in a flue gas concentration of SO 2 exceeding 2000 ppmv. In the second campaign, the fuel applied was a low-S blended coal and the SO 2 concentration in the raw gas was around 400 ppmv. A novel probe for in situ sampling of gas phase concentrations in wet FGD spray absorbers was developed and applied for measuring axial profiles of the SO 2 gas phase concentrations in the absorber. The expected decrease in SO 2 concentrations along the height of the absorber was found in the spray section (from height 26.5 to 36.2 m) whereas the SO 2 concentration above the holding tank and below the gas inlet was quite low probably due to long local residence times in the region. Horizontal variations, due to somewhat different flow conditions near the column wall were investigated and the SO 2 concentrations were found to be higher near the wall. Measurements at different gross loads showed that the SO 2 gas phase concentration at a given position inside the absorber was roughly linearly related to the L/G ratio in the measuring interval. Turning off one of the lower spray levels, while burning coal with low S content, did not lower the overall removal efficiency of the absorber. However, the SO 2 gas phase concentration inside the lower part of the absorber was increased by a factor of 2–3. Measurements of slurry pH at different positions showed a decrease of approximately 0.5 units from the upper to the lower part of the absorber. The full-scale measurements provide a detailed set of experimental data for validation of mathematical models of a wet FGD spray absorber.