In this paper, we propose a scheme to generate tunable multi-color attosecond coherent X-ray radiation for future light source applications. This scheme uses an energy chirped electron beam, a laser modulators, a laser chirper and two bunch compressors to generate a multi-spike prebunched kilo-Ampere current electron beam from a few tens Ampere electron beam out of a linac. Such an electron beam transports through a series of undulator radiators and bunch compressors to generate multi-color coherent X-ray radiation. As an illustration, we present an example to generate two attosecond pulses with $2.2$ nm and $3$ nm coherent X-ray radiation wavelength and more than $200$ MW peak power using a $30$ Ampere $200$ nm laser seeded electron beam.
A new method to generate short wavelength Free Electron Laser output with modulated polarisation at attosecond timescales is presented. Simulations demonstrate polarisation switching timescales that are four orders of magnitude faster than the current state of the art and, at X-Ray wavelengths, approaching the atomic unit of time of approximately $24$~attoseconds. Such polarisation control has significant potential in the study of ultra-fast atomic and molecular processes. The output alternates between either orthogonal linear or circularly polarised light without the need for any polarising o…
Attosecond Compression of Relativistic Electron Pulses via Continuous Harmonic Undulator Resonance
Institute of Advanced Light Source Facilities, Shenzhen（深圳先进光源设施研究所）；School of Electrical and Electronic Engineering, Huazhong University of Science and Technology（华中科技大学电气与电子工程学院）；State Key Laboratory of Chemical Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences（中国科学院大连化学物理研究所化学反应动力学国家重点实验室）
Dielectric laser acceleration is a versatile scheme to accelerate and control electrons with the help of femtosecond laser pulses in nanophotonic structures. We demonstrate here the generation of a train of electron pulses with individual pulse durations as short as $270\pm80$ attoseconds(FWHM), measured in an indirect fashion, based on two subsequent dielectric laser interaction regions connected by a free-space electron drift section, all on a single photonic chip. In the first interaction region (the modulator), an energy modulation is imprinted on the electron pulse. During free propagatio…
U-Net-based surrogate modeling for attosecond X-ray free-electron lasers
Shanghai Institute of Applied Physics, Chinese Academy of Sciences（中国科学院上海应用物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）；European XFEL（欧洲X射线自由电子激光设施）；Deutsches Elektronen-Synchrotron DESY（德国电子同步辐射中心）；Shanghai Advanced Research Institute, Chinese Academy of Sciences（中国科学院上海高级研究院）
High-power attosecond X-ray free-electron lasers: physics and design strategy
Shanghai Institute of Applied Physics, Chinese Academy of Sciences（中国科学院上海应用物理研究所）；University of Chinese Academy of Sciences（中国科学院大学）；European XFEL（欧洲XFEL）；Deutsches Elektronen-Synchrotron DESY（德国电子同步加速器）；Shanghai Advanced Research Institute, Chinese Academy of Sciences（中国科学院上海高等研究院）
Broadband hard X-ray attosecond pulses from extremely chirped electron beams
SLAC National Accelerator Laboratory（斯坦福直线加速器中心）；Department of Applied Physics, Stanford University（斯坦福大学应用物理系）；Stanford PULSE Institute, SLAC National Accelerator Laboratory（斯坦福PULSE研究所，斯坦福直线加速器中心）
Shaping electron beams with the cycles of light provides femtosecond and attosecond time resolution in electron microscopy and enables fundamental quantum-coherent measurements. However, efficient light-electron control requires a prolonged interaction between the two beams for cascaded transfer of photon energy and momentum to the freely propagating electrons. Here we report the use of traveling evanescent terahertz waves to achieve velocity matching and thereby high acceleration gradients both in space and in time. With experiment and simulations, we demonstrate attosecond streaking, tempora…
Phase-Stable Self-Modulation for GHz Continuous-Wave Ultrafast X-Ray Free-Electron Lasers
Shanghai Advanced Research Institute, Chinese Academy of Sciences（中国科学院上海高等研究院）；University of Chinese Academy of Sciences（中国科学院大学）；Zhangjiang Laboratory（张江实验室）
