LINAC2026 - 33rd Linear Accelerator Conference

High-Power Testing of an X-Band Dielectric Assist Accelerating Structure under Short-Pulse RF Excitation

Not scheduled

2h

Daejeon Convention Center

Poster Presentation MC2.A06: Other electron accelerators Poster Session

Speaker

DAISUKE SATOH (National Institute of Advanced Industrial Science and Technology)

Description

The dielectric assist accelerating (DAA) structure is a power-efficient RF accelerating cavity. A room-temperature C-band DAA structure has demonstrated a high shunt impedance of approximately 600 MΩ/m. Nevertheless, the attainable accelerating field in DAA structures has so far been limited to approximately 10–12 MV/m, mainly because of RF breakdown-related phenomena, including multipacting.
To increase the achievable accelerating field, we have investigated short-pulse RF excitation in DAA structures. This approach is motivated by recent studies of dielectric disk accelerating structures, in which an accelerating gradient exceeding 100 MV/m was achieved under short-pulse operation.
We have developed a two-cell X-band standing-wave DAA structure employing sapphire cells coated with hydrogenated amorphous carbon. High-power RF tests have been carried out at Nextef2 in KEK. We tested different RF pulse conditions, including single RF pulses shorter than the cavity filling time and step-pulse inputs, and achieved an accelerating field of up to 16 MV/m.
In this presentation, we will describe recent efforts toward higher-gradient operation.