Marx Based Modulator for ILC and Industry

The International Linear Collider (ILC) will require hundreds of klystron pulsed-power modulators that must operate in the very long pulse-width range (1 to 2 millisecond). Long pulse width modulators typically require large capacitive energy storage banks to prevent voltage droop, and large, costly pulse transformers. Marx-generator-based modulators have the potential to be effective for this application; however, little work has been done to tailor this type of modulator for long pulse widths. This project will develop a Marx-based modulator that is tailored to meet the specific requirements of the ILC. The approach will focus on a novel combination of Marx cells with unique control technology, which will dramatically reduce the modulator¿s capacitive energy storage while still meeting the precision pulse regulation required. In Phase I, circuit simulations and analyses were performed to optimize the configuration of the Marx-based modulator. Key components were defined and evaluations of these components were made to determine their suitability for this application. A conceptual design and a cost model were developed for the Marx cells, regulation circuits, and the entire modulator. Emphasis was placed on compactness while maintaining serviceability. In Phase II, a full sized Marx-based modulator, which meets the requirements of the ILC program, will be designed and constructed. Subsystem tests will be conducted to verify key component performance prior to modulator system construction. The modulator will be delivered to the Stanford Linear Accelerator Center (SLAC) for evaluation, and comparison with other modulators. Commercial Applications and other Benefits as described by the awardee: The new Marx-based modulator should provide a cost-effective solution for the International Linear Collider. In addition, the modulator should have important commercial applications, including its use in radiation processing equipment for materials processing, disinfestation, food irradiation, and other electron beam processing industries where long-pulse, high-average-power sources are required. The variable pulse width and high repetition rate also would make this modulator a valuable microwave source for cargo inspection systems.