Single-stage plasma-based correlated energy spread compensation for ultrahigh 6D brightness electron beams.
Single-stage plasma-based correlated energy spread compensation for ultrahigh 6D brightness electron beams.
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DOI：
10.1038/ncomms15705
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发表时间：
2017-06-05
影响因子：
16.6
通讯作者：
Hidding B
中科院分区：
文献类型：
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作者：
Manahan GG;Habib AF;Scherkl P;Delinikolas P;Beaton A;Knetsch A;Karger O;Wittig G;Heinemann T;Sheng ZM;Cary JR;Bruhwiler DL;Rosenzweig JB;Hidding B
等离子体光阴极韦克菲尔德场加速将数十GeV m−1的能量增益与超低发射率电子束的产生相结合，开辟了一条通往比最先进水平大几个数量级的5D亮度的道路。这为紧凑型加速器构建模块和先进光源带来了巨大的希望。然而，等离子体加速器所固有的巨大电场梯度的一个内在副产品是大量的相关能量扩散，这是自由电子激光器等关键应用的一个障碍。在这里，我们表明，通过释放一个额外的定制的护送电子束在稍后阶段的加速，当见证聚束是相对论稳定的，等离子体波可以局部过载，而不损害见证聚束归一化发射度。这反转了有效加速梯度，并且反向旋转了见证聚束的累积的负纵向相位空间啁啾。因此，能量扩散减小了一个数量级，从而能够产生106D亮度的光束。控制和改善电子束参数是其在自由电子激光和X射线源中应用的关键。在这里，作者产生质量的电子束与减少的能量扩散从等离子体加速器通过使用定制的护送电子束与主加速束。
Plasma photocathode wakefield acceleration combines energy gains of tens of GeV m−1 with generation of ultralow emittance electron bunches, and opens a path towards 5D-brightness orders of magnitude larger than state-of-the-art. This holds great promise for compact accelerator building blocks and advanced light sources. However, an intrinsic by-product of the enormous electric field gradients inherent to plasma accelerators is substantial correlated energy spread—an obstacle for key applications such as free-electron-lasers. Here we show that by releasing an additional tailored escort electron beam at a later phase of the acceleration, when the witness bunch is relativistically stable, the plasma wave can be locally overloaded without compromising the witness bunch normalized emittance. This reverses the effective accelerating gradient, and counter-rotates the accumulated negative longitudinal phase space chirp of the witness bunch. Thereby, the energy spread is reduced by an order of magnitude, thus enabling the production of ultrahigh 6D-brightness beams. Controlling and improving electron beam parameters are crucial for their application in free electron laser and X-ray sources. Here the authors generate quality electron beams with reduced energy spread from plasma accelerators by using a tailored escort electron bunch with the main accelerating bunch.