Particle-beam-driven plasma wakefield acceleration: Milestones, emerging trends and future directions

Over the past four decades, extensive research in particle-beam-driven plasma wakefield acceleration has progressed along three primary pathways: electron-driven, positron-driven, and proton-driven wakefield generation. Several accelerator facilities worldwide have made significant contributions to research and progress in this field, with remarkable milestones achieved. New ideas and technologies continue to emerge, offering considerable potential to reduce the size and cost of future accelerators. This review paper presents the foundational theories of beam-driven plasma wakefield acceleration, emphasizing key scaling laws and practical formulas. Then by adopting a chronological approach on electron-driven plasma wakefield acceleration, it explores major experimental milestones, surveys current research facilities and their ongoing investigations, and outlines the key challenges ahead. In addition, positron acceleration and wakefield generation are also reviewed, with a focus on experimental efforts and the unique challenges they present. Furthermore, the paper also covers the fundamental physics, experimental achievements, and current research in proton-driven plasma wakefield acceleration. Together, these three pathways are strategically advancing toward their ultimate applications in future compact particle colliders and X-ray light sources. The paper discusses the policies, strategies, and emerging innovative concepts that are aiming at realizing these ambitious goals.