Deutsches Elektronen-Synchrotron DESY, 22607 Hamburg, Germany.
Institut für Experimentalphysik, Universität Hamburg, 22761 Hamburg, Germany.
Phys Rev Lett. 2019 Aug 2;123(5):054801. doi: 10.1103/PhysRevLett.123.054801.
The extreme electromagnetic fields sustained by plasma-based accelerators could drastically reduce the size and cost of future accelerator facilities. However, they are also an inherent source of correlated energy spread in the produced beams, which severely limits the usability of these devices. We propose here to split the acceleration process into two plasma stages joined by a magnetic chicane in which the energy correlation induced in the first stage is inverted such that it can be naturally compensated in the second. Simulations of a particular 1.5-m-long setup show that 5.5 GeV beams with relative energy spreads of 1.2×10^{-3} (total) and 2.8×10^{-4} (slice) could be achieved while preserving a submicron emittance. This is at least one order of magnitude below the current state of the art and would enable applications such as compact free-electron lasers.
基于等离子体的加速器所承受的极端电磁场可以大幅减小未来加速器设施的尺寸和成本。然而，它们也是产生束流中相关能量扩散的固有源，这严重限制了这些设备的可用性。我们在此提议将加速过程分为两个等离子体阶段，由一个磁扭摆器连接，在第一阶段中诱导的能量相关性在第二阶段中被反转，从而可以自然地补偿。对一个特定的 1.5 米长的设置的模拟表明，可以实现具有相对能量扩散度为 1.2×10^{-3}（总）和 2.8×10^{-4}（切片）的 5.5 GeV 束流，同时保持亚微米的发射度。这至少比当前的技术水平低一个数量级，将能够实现诸如紧凑型自由电子激光器等应用。
