Relativistic laser plasmas for electron acceleration and short wavelength radiation generation
Relativistic laser plasmas for electron acceleration and short wavelength radiation generation
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DOI：
10.1088/0741-3335/52/12/124039
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发表时间：
2010-11
影响因子：
2.2
通讯作者：
A. Pukhov;D. Brügge;I. Kostyukov
中科院分区：
文献类型：
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作者：
A. Pukhov;D. Brügge;I. Kostyukov
我们在这里考虑几种选择，使用相对论激光等离子体的短波长辐射的新来源。在低密度等离子体中被加速的电子在离子通道中摆动。这导致了飞秒持续时间的宽带非相干同步辐射爆发。光子能量在千电子伏到兆电子伏的能量范围内。然而，这种辐射是不相干的。为了达到相干性，电子聚束必须在发射的X射线的波长处具有结构。原则上，这可以通过将激光加速的电子聚束发送通过外部摇摆器来实现。然而，为了在X射线范围内实现自由电子激光发射，激光加速电子的能量扩散必须大幅降低。另一种选择是在过密等离子体边界处使用高次谐波产生。高次谐波在相干亚飞秒闪光中发射。谐波谱以谐波数的幂衰减，其指数可以低至−6/5。这可以使高次谐波潜在地成为具有独特性质的最亮的激光驱动短波长源。
We consider here a few options to use relativistic laser plasmas for novel sources of short wavelength radiation. Electrons accelerated in underdense plasmas in the bubble regime wiggle in an ion channel. This leads to broadband incoherent synchrotron-like radiation bursts which are of femtosecond duration. The photon energies are in the kiloelectronvolt to megaelectronvolt energy range. However, this radiation is not coherent. To reach coherency, the electron bunch must have structure at the wavelength of the emitted x-rays. This can be achieved in principle by sending the laser-accelerated electron bunch through an external wiggler. However, to reach free electron lasing in the x-ray regime, the energy spread of the laser-accelerated electrons must be reduced dramatically. Another option is to use high harmonic generation at overdense plasma boundaries. The high harmonics are emitted in coherent sub-femtosecond flashes. The harmonic spectra decay as a power of the harmonic number, with an exponent that can be as low as −6/5. This can make the high harmonics potentially the brightest laser-driven short wavelength sources with unique properties.