RF Accelerator Technology R&D: Report of AF7-rf Topical Group to Snowmass 2021

TL;DR

This report summarizes recent advancements in RF accelerator technology, highlighting progress over the past decade that supports upgrades, new projects, and applications across high energy physics and other scientific fields.

Contribution

It provides a comprehensive overview of recent RF technology developments and outlines future R&D directions for accelerator upgrades and new concepts.

Findings

Significant progress in RF technology over the past decade.

Potential for upgrades to existing facilities and new accelerator proposals.

Impact of RF advances on various scientific and industrial applications.

Abstract

Accelerator radio frequency (RF) technology has been and remains critical for modern high energy physics (HEP) experiments based on particle accelerators. Tremendous progress in advancing this technology has been achieved over the past decade in several areas highlighted in this report. These achievements and new results expected from continued R&D efforts could pave the way for upgrades of existing facilities, improvements to accelerators already under construction (e.g., PIP-II), well-developed proposals (e.g., ILC, CLIC), and/or enable concepts under development, such as FCC-ee, CEPC, C3, HELEN, multi-MW Fermilab Proton Intensity Upgrade, future Muon Colloder, etc. Advances in RF technology have impact beyond HEP on accelerators built for nuclear physics, basic energy sciences, and other areas. Recent examples of such accelerators are European XFEL, LCLS-II and LCLS-II-HE, SHINE, SNS, ESS, FRIB, and EIC. To support and enable new accelerator-based applications and even make some of them feasible, we must continue addressing their challenges via a comprehensive RF R&D program that would advance the existing RF technologies and explore the nascent ones.