Snowmass2021 Topical Group Report from AF07: Targets and Sources

TL;DR

This report reviews the challenges and R&D directions for high-power accelerator targets and sources, emphasizing novel designs, materials, and international collaboration to meet future high-power requirements.

Contribution

It identifies four main R&D tracks for targets and discusses current challenges and future directions for electron and ion sources in high-power accelerators.

Findings

Need for advanced cooling and novel materials for targets

Current challenges in electron source components like cathodes and guns

Development priorities for ion sources such as ECRIS and laser ion sources

Abstract

For the next multi-megawatt accelerator generation, targets and other beam-intercepting components will face even more severe challenges due to the higher power densities, higher energy, and higher radiation. A comprehensive research and development program must be implemented to address the challenges. International collaborations such as RaDIATE or High Power Targetry Workshop should be leveraged and expanded to accelerate knowledge gain and avoid duplicated efforts. The next generation of high power targets will need novel designs allowing better high heat flux cooling methods, novel materials, advanced simulations, and better instrumentation. Four main R&D tracks were identified and discussed for targets. For electron sources, current state of art and challenges we are facing for key components such as cathodes, guns and injector design for sources R&D are presented for highly polarized electrons and unpolarized high current high brightness beams. For ion sources such as electron cyclotron resonance ion source (ECRIS), laser ion source (LIS), charge breeders, status of development are reviewed, and areas require investment for future R&D are discussed separately. Facilities critical for various source development are recommended.