THz radiation promises breakthrough advances in compact advanced accelerators due to the high frequency and GV/m fields achievable, orders of magnitude larger than in conventional radiofrequency (RF) based accelerators. Compared to laser-driven schemes, the large phase acceptances of THz-driven accelerators are advantageous for operation with sizable charge. Despite burgeoning research, THz sources, particularly laser-based ones, cannot yet compete with the efficiency of RF amplifiers for high average current accelerators. Nevertheless, THz-based phase space manipulation is of immediate interest for a variety of applications, including generation and diagnostics of ultrashort bunches for electron diffraction/microscopy and compact free-electron laser applications.
The challenge of maintaining overlap and synchronism between an electron beam and short laser-generated THz pulse has so far limited interactions to the few mm scale. We discuss a novel scheme for simultaneous group and phase velocity matching of nearly single-cycle THz radiation with a relativistic electron beam for meter-scale interaction. We demonstrate energy modulations of up to 150 keV using modest THz pulse energies (up to 1 uJ). We apply this large and efficient energy exchange for beam compression and time-stamping of a relativistic beam, paving the way towards realizing the unique opportunities enabled by laser-based THz accelerators.
Staged Laser Wakefield Acceleration for Saturated Lasing of Bandwidth-Tunable Free-Electron Lasers from EUV to X-ray
Tsinghua University（清华大学）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；Beijing Academy of Quantum Information Science（北京量子信息科学研究院）；University of Chinese Academy of Sciences（中国科学院大学）
Terahertz-driven electron acceleration from subrelativistic to fully relativistic energies in stepped dielectric-lined waveguides
The Cockcroft Institute（科克沃尔研究所）；Sci-Tech Daresbury（达尔斯伯里科学与技术中心）；Department of Physics and Astronomy & Photon Science Institute, The University of Manchester（曼彻斯特大学物理与天文学系及光子科学研究所）
Controlling external injection in laser-plasma accelerators with terahertz frequency bunch manipulation
The Cockcroft Institute（科克沃尔研究所）；Science and Technology Facilities Council（科学与技术设施委员会）；The University of Manchester（曼彻斯特大学）；University of Liverpool（利物浦大学）
Terahertz-based longitudinal phase space diagnostics of laser wakefield accelerated electron beams
Tsinghua University（清华大学）；Institute of High Energy Physics, Chinese Academy of Sciences（中国科学院高能物理研究所）；Beijing Academy of Quantum Information Sciences（北京量子信息科学研究院）
