CLIC – Multi-decade investment in HG technology development. Major success in achieving gradient specifications in multiple prototypes and deep understanding of fundamentals of high gradient. Systems level engineering next step, plus for example dedicated R&D on manufacturing, and mechanical design and micron-level alignment system.
Muon Collider – Major NC parameter is high-gradient in magnetic field. Significant need for dedicated test infrastructure.
Fundamental mechanisms of breakdown – University and laboratory-based experimental and experimental activities in surface physics, material science, plasma physics and electrodynamics. Wide applicability.
New concepts – Normal conducting RF had multiple new directions, for example dielectric structures, short pulse acceleration and high-temperature superconductors.
Applications – Significant integrated resources, greater than currently coming from HEP. Providing strong stimulus for industrial supply of NC RF components and systems.
Current directions:
Bringing on line the multiple applications to make high-gradient NC RF reliable and cheap (e.g. medical applications, light sources)! Extend range of applicability (e.g. Muon Collider, RFQ) as well as support advanced accelerator development (e.g. EuPraxia). Maintaining existing RF test infrastructure (e.g. CERN XBoxes, INFN TEX, Uppsala cryo pulsed dc system, etc.) crucial for future progress and application of technology.