High-Gradient Acceleration with Short Pulses*

High-energy particle accelerators are crucial to the next big discovery in particle physics. To reduce the size and cost of particle accelerators, increasing the accelerating gradient (energy gain per unit length for the particle beam) is of critical importance. Advanced accelerator concepts (AACs) hold the promise of revolutionary future particle colliders with dramatically higher gradients than what conventional accelerator technologies allow. Structure wakefield acceleration (SWFA) is one AAC scheme, which aims to raise the gradient and the efficiency by confining the microwave energy in a short and intense RF pulse. In recent SWFA studies at the Argonne Wakefield Accelerator facility at the Argonne National Laboratory, we have demonstrated the potential of using short RF pulses with a duration of a few nanoseconds for high-gradient acceleration. One new acceleration regime, named the Breakdown Insensitive Acceleration Regime (BIAR), has been discovered. This new regime, BIAR, could directly contribute to long-term large-scale applications, including AAC-based colliders and compact light sources.