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Zhang, W.

Paper Title Page
MOPAS104 Large Scale Distributed Parameter Model of Main Magnet System and Frequency Decomposition Analysis 670
  • W. Zhang, I. Marneris, J. Sandberg
    BNL, Upton, Long Island, New York
  Funding: Work performed under auspices of U. S. Department of Energy.

Large accelerator main magnet system consists of hundreds, even thousands, of dipole magnets. They are linked together under selected configurations to provide highly uniform dipole fields when powered. Distributed capacitance, insulation resistance, coil resistance, magnet inductance, and coupling inductance of upper and lower pancakes make each magnet a complex network. When all dipole magnets are chained together in a circle, they become a coupled pair of very high order complex ladder networks. In this study, a network of more than thousand inductive, capacitive or resistive elements are used to model an actual system. The circuit is a large scale network. Its equivalent polynomial form has several hundred degrees. Analysis of this high order circuit and simulation of the response of any or all components is often computationally infeasible. We present methods to use frequency decomposition approach to effectively simulate and analyze magnet configuration and power supply topologies.

MOPAS105 Analysis and Simulation of Main Magnet Transmission Line Effect 673
  • W. Zhang, I. Marneris, J. Sandberg
    BNL, Upton, Long Island, New York
  Funding: Wor performed under auspices of U. S. Departemnt of Energy.

A main magnet chain forms a pair of transmission lines. Pulse-reflection-caused voltage and current differentiation throughout the magnet chain can have adverse effect on main magnet field quality. This effect is associated with magnet system configuration, coupling efficiency, and parasitic parameters. A better understanding of this phenomenon will help us in new design and existing system upgrade. In this paper, we exam the transmission line effect due to different input functions as well as configuration, coupling, and other parameters.

WEPMS092 A Simplified Approach to Analyze and Model Inductive Voltage Adder 2553
  • W. Zhang, W. Eng, C. Pai, J. Sandberg, Y. Tan, Y. Tian
    BNL, Upton, Long Island, New York
  Funding: Work performed under auspices of U. S. Departemnt of Energy.

We have recently developed a simplified model and a set of simple formulas for inductive voltage adder design. This model reveals the relationship of output waveform parameters and hardware designs. A computer simulation has demonstrated that parameter estimation based on this approach is accurate as compared to an actual circuit. This approach can be used in early stages of project development to assist feasibility study, geometry selection in engineering design, and parameter selection of critical components. In this paper, we give the deduction of a simplified model. Among the estimation formulas we present are those for pulse rise time, system impedance, and number of stages. Examples are used to illustrate the advantage of this approach. This approach is also applicable to induction LINAC design.