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R.L. Ives,
A. Attarian,
T. Bui,
M. Read, J. David,
H. Tran,
W.J. Tallis,
S. Davis,
S.E. Gadson,
N. Blach,
D. Brown,
E. Kiley
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ABSTRACT: Three-dimensional design codes are allowing the development of more complex electron beam devices with significant performance improvements over axially symmetric devices. Distributed beam RF devices, including multiple-beam and sheet-beam designs, allow significant reduction in operating voltage with improved efficiency and bandwidth. The increased parameter space, however, makes the design process extremely complicated and costly. This paper describes optimization techniques to automate the most time-consuming tasks of the design, which is searching the available parameter space to optimize performance. Both sheet-beam and multiple-beam designs are considered.
IEEE Transactions on Electron Devices 06/2009; · 2.32 Impact Factor
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ABSTRACT: Calabazas Creek Research, Inc. (CCR) and North Carolina State University are developing optimization techniques for advanced, 3D, electron guns. Our approach uses advanced solid modeling CAD programs capable of controlling geometrical parameters with design tables manipulated by an optimization control program. Geometrical and parametric changes are simulated using a 3D, finite element, adaptive meshing charged particle program. Results of the beam analysis are analyzed and an optimization routine modifies the parameters to obtain user-defined performance goals. These techniques are applied to a number of gun geometries, and the results are described.
Vacuum Electronics Conference, 2008. IVEC 2008. IEEE International; 05/2008
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ABSTRACT: This paper considers the problem of designing electron guns using computer optimization techniques. Several different design parameters are manipulated while considering multiple design criteria, including beam and gun properties. The optimization routines are described. Examples of guns designed using these techniques are presented. Future research is also described.
IEEE Transactions on Plasma Science 03/2008; · 1.17 Impact Factor
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ABSTRACT: Computer optimization is applied to three dimensional design of electron guns. The resulting designs exhibit improved performance with significantly reduced design cost compared to manual design. Design tables update geometric parameters in a solid modeling program, including dimensions for points defining spline surfaces. Algorithms then modified the geometry and other parameters based on goal functions defining the desired performance. Optimal designs were achieved by automatic execution of the optimization loop. Results for confined flow Pierce guns, sheet beam guns, and multiple beam guns will be described.
Infrared and Millimeter Waves, 2007 and the 2007 15th International Conference on Terahertz Electronics. IRMMW-THz. Joint 32nd International Conference on; 10/2007
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ABSTRACT: Computer optimization can explore a wider parameter space than practical with manual design, particularly for 3D geometries. This allows rapid, economical development of higher performance devices. The proliferation of parametric solid modeling programs allows optimization of both geometry and operating parameters. This presentation described computer optimization in the 3D trajectory code beam optics analysis (BOA). This is possible because meshing in BOA is completely automatic, allowing the program to be controlled by the optimization routines.
Infrared Millimeter Waves and 14th International Conference on Teraherz Electronics, 2006. IRMMW-THz 2006. Joint 31st International Conference on; 10/2006
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ABSTRACT: Summary form only given. Calabazas Creek Research (CCR) and North Carolina State University implemented several novel features into the optimization capabilities of the large signal traveling wave tube (TWT) interaction code, Christine1D. The internal optimization capabilities of Christine1D are currently limited to the design of helix circuits. The present scheme varies a geometric parameter, such as the helix pitch, and calculates the corresponding cold-test characteristics, including phase velocity and interaction impedance, using an analytical sheath or tape helix model. To expand the flexibility of the code to other types of slow wave structures, we have introduced the option to define the dependence of these cold-test characteristics manually. These characteristics, and their dependence on variations to geometric parameters as would be implemented in a phase velocity taper, can be very accurately determined using a three-dimensional code such as Microwave Studio. Then, the user defines this dependence in Christine1D through curve fitting equations. Currently, Christine1D employs a modified steepest descent method to carry out the optimization process. We have used both the Nelder-Mead and the DIRECT algorithms. Optimization results will be presented showing a significant improvement over the currently implemented steepest descent model. Lastly, Christine1D has a limited number of design goal functions. Several new goal functions were introduced where the user has the option of using them simultaneously with weighting schemes depending on the application. These goal functions were used to design a W-band folded waveguide TWT circuit according to the specifications supplied by the customer. Results for several goal function combinations will be presented.
Plasma Science, 2005. ICOPS '05. IEEE Conference Record - Abstracts. IEEE International Conference on; 07/2005
