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DOE OSTI · 1960029

High gradient off-axis coupled C-band Cu and CuAg accelerating structures

Schneider, Mitchell·Dolgashev, Valery·Lewellen, John W.·Tantawi, Sami G.·Nanni, Emilio A.·Zuboraj, Muhammed·Fleming, Ryan·Gorelov, Dmitry·Middendorf, Mark·Simakov, Evgenya I.
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Abstract

Here, we report the high gradient testing results of two single-cell off-axis coupled standing wave accelerating structures. Two brazed standing wave off-axis coupled structures with the same geometry were tested: one made of pure copper (Cu) and one made of a copper–silver (CuAg) alloy with a silver concentration of 0.08%. A peak surface electric field of 450 MV/m was achieved in the CuAg structure for a klystron input power of 14.5 MW and a 1 μs pulse length, which was 25% higher than the peak surface electric field achieved in the Cu structure. The superb high gradient performance was achieved because of the two major optimizations in the cavity's geometry: (1) the shunt impedance of the cavity was maximized for a peak surface electric field to accelerating gradient ratio of ~2 for a fully relativistic particle, and (2) the peak magnetic field enhancement due to the input coupler was minimized to limit pulse heating. These tests allow us to conclude that C-band accelerating structures can operate at peak fields similar to those at higher frequencies while providing a larger beam iris for improved beam transport.

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71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS

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Schneider, Mitchell, Dolgashev, Valery, Lewellen, John W., Tantawi, Sami G., Nanni, Emilio A., Zuboraj, Muhammed, Fleming, Ryan, Gorelov, Dmitry, Middendorf, Mark, Simakov, Evgenya I.. 2022-12-20. High gradient off-axis coupled C-band Cu and CuAg accelerating structures. https://doi.org/10.1063/5.0132706

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