Speaker
Description
Structure wakefield acceleration is an advanced accelerator concept which employs short drive electron bunches as compact power sources to accelerate witness bunches. It is promising to raise the accelerating gradient, which is limited to about 100 MV/m in conventional RF accelerators due to RF breakdowns, by confining an intense wakefield in short RF pulses. Based on the extensive research in the high gradient acceleration community, using short RF pulses could mitigate the risk of RF breakdown and increase the operating gradient as a result. In a few recent experiments at the Argonne Wakefield Accelerator (AWA), including an X-band single-cell metallic structure, and an X-band metamaterial accelerating structure, we discovered evidence for a new operating regime, named the breakdown insensitive accelerating regime (BIAR), where the RF pulse for acceleration (or the accelerating field in the structure) is not disrupted in a breakdown event. The pulse length is short, on the order of a few nanoseconds. The BIAR regime could lead to high-gradient acceleration as well as breakthrough in understanding RF breakdown physics.
Acknowledgments
The work at the AWA was funded through the U.S. Department of Energy, Office of Science under Contract No. DE-AC02-06CH11357.The work at NIU was supported by the U.S. Department of Energy, Office of Science, Office of High Energy Physics under Award DE-SC0021928, and the Chicagoland Accelerator Science Traineeship (CAST) program sponsored by
the U.S. DOE award DE-SC0020379.
