Numerical study of electron acceleration and betatron radiation base on the interaction of petawatt femtosecond laser with near-critical-density plasma
-
摘要: 针对典型拍瓦级飞秒激光装置参数，提出一种毛细管型的气室结构靶以产生百微米尺度且具有陡峭的密度上升沿的近临界密度等离子体。该气室结构靶具有背压低、喷气量小的特点。由于气室壁约束，气室内，该气室靶可更加稳定产生平台状的气体密度分布。采用粒子模拟方法研究了拍瓦级飞秒激光与该近临界密度等离子体相互作用的电子加速及Betatron辐射过程。结果表明，合适气体密度和激光脉宽有利于产生稳定的等离子体通道。在通道内，电子首先经历有效的激光尾波场加速。这些加速的高能电子与激光尾部直接作用，通过Betatron共振和激光直接加速，可使其产额及截止能量进一步提升。该大电荷量高能电子束在等离子体通道内的横向振荡能够产生高亮度Betatron辐射源，峰值光子能量约8 keV，亮度达到
$ 1.75\times {10}^{20}\;\mathrm{p}\mathrm{h}\cdot {\mathrm{s}}^{-1}\cdot {\mathrm{mm}}^{-2}\cdot $ $ {\mathrm{m}\mathrm{rad}}^{-2}\cdot {\left(0.1\mathrm{{\text{%}}}\mathrm{b}\mathrm{w}\right)}^{-1} $ 。此外，还重点研究了气体密度及激光脉宽对Betatron辐射源的影响并阐述了内在机理。-
关键词:
- 拍瓦飞秒激光 /
- 电子加速 /
- Betatron辐射 /
- 粒子模拟
Abstract: Laser-driven high-brightness betatron radiation has great potentials for its broad applications in the detection of ultrafast processes (such as shock waves or implosion processes) in high energy density physics. Here a tube-like gas-cell target is proposed to generate a near-critical-density (NCD) plasma, which has a sharped rising edge with a length scale of hundreds of μm. Such a gas-cell target has the advantages of low back pressure and small jet volume. Moreover, due to the confinement of the gas chamber walls, it can more stably generate a plateau-shaped gas density distribution. Particle-in-cell (PIC) simulations of the the petawatt femtosecond laser interacting with such a NCD plasma were carried out to study the electron acceleration as well as the betatron radiation. It was shown that, with the appropriate gas density and pulse duration, a steady plasma channel can be well formed. In the channel, the electrons firstly undergo the wakefield acceleration. Then these energetic electrons directly interact with the laser tail, where the efficient betatron resonance and the direct laser acceleration happen, thus resulting in the great enhancement of both the yield and cut-off energy. The transverse oscillation of energetic electrons in the plasma channel leads to the production of high brightness betatron radiation, which has a critical photon energy of 8keV and a brightness of$ 1.75\times {10}^{20}\;\mathrm{p}\mathrm{h}\cdot {\mathrm{s}}^{-1}\cdot {\mathrm{mm}}^{-2}\cdot {\mathrm{m}\mathrm{rad}}^{-2}\cdot {\left(0.1\mathrm{{\text{%}}}\mathrm{b}\mathrm{w}\right)}^{-1} $ . The influences of the gas density and laser pulse duration on the betatron radiation were also identified. These results provide an effective path for optimizing the generation of high brightness betatron radiation using the petawatt femtosecond lasers. -
图 1 气室靶结构及气体密度分布图
Figure 1. Target structure of the gas chamber and distribution map of gas density
图 2 不同气压条件下，激光到达气体密度平台区时刻（t=600T0）的电子密度空间分布及中心轴上激光场强分布
Figure 2. The spatial distributions of electron density and on-axis laser field at t=600T0 while the laser reaches the gas density plateau region for different pressures
图 3 不同气压条件下激光到达气体密度平台区时（t=600T0）的加速电子角分布及能谱
Figure 3. The angular distributions of accelerated electrons and the energy spectral at t=600T0 while the laser reaches the gas density plateau region for different pressures
图 4 不同气压条件下激光作用结束时（t=1200T0）的Betatron辐射角分布及光子能谱
Figure 4. The angular distributions of betatron radiations and the photon energy spectral at t=1200T0
图 5 不同脉宽激光与气室靶（64 kPa）作用产生的电子能谱（a）及Betatron辐射能谱（b）
Figure 5. The electron spectral (a) and betatron radiation spectral (b) for different laser pulse durations
-
[1] Corde S, Ta Phuoc K, Lambert G, et al. Femtosecond x rays from laser-plasma accelerators[J]. Reviews of Modern Physics, 2013, 85(1): 1-48. doi: 10.1103/RevModPhys.85.1 [2] 鲁瑜, 张昊, 张亮琪, 等. 基于激光等离子体的X/γ辐射研究进展[J]. 强激光与粒子束, 2023, 35:012006Lu Yu, Zhang Hao, Zhang Liangqi, et al. Research progress of X/γ photon emission in laser-plasma interaction[J]. High Power Laser and Particle Beams, 2023, 35: 012006 [3] Mahieu B, Jourdain N, Ta Phuoc K, et al. Probing warm dense matter using femtosecond X-ray absorption spectroscopy with a laser-produced betatron source[J]. Nature Communications, 2018, 9: 3276. doi: 10.1038/s41467-018-05791-4 [4] Ping Y, Hicks D G, Yaakobi B, et al. A platform for x-ray absorption fine structure study of dynamically compressed materials above 1 mbar[J]. Review of Scientific Instruments, 2013, 84: 123105. doi: 10.1063/1.4841935 [5] Ravasio A, Koenig M, Le Pape S, et al. Hard x-ray radiography for density measurement in shock compressed matter[J]. Physics of Plasmas, 2008, 15: 060701. doi: 10.1063/1.2928156 [6] Wood J C, Chapman D J, Poder K, et al. Ultrafast imaging of laser driven shock waves using betatron x-rays from a laser wakefield accelerator[J]. Scientific Reports, 2018, 8: 11010. doi: 10.1038/s41598-018-29347-0 [7] Döpp A, Hehn L, Götzfried J, et al. Quick x-ray microtomography using a laser-driven betatron source[J]. Optica, 2018, 5(2): 199-203. doi: 10.1364/OPTICA.5.000199 [8] Zhang Z M, Zhang B, Hong W, et al. Enhanced x-rays from resonant betatron oscillations in laser Wakefield with external wigglers[J]. Plasma Physics and Controlled Fusion, 2016, 58: 105009. doi: 10.1088/0741-3335/58/10/105009 [9] Ferri J, Corde S, Döpp A, et al. High-brilliance betatron γ-ray source powered by laser-accelerated electrons[J]. Physical Review Letters, 2018, 120: 254802. doi: 10.1103/PhysRevLett.120.254802 [10] Esarey E, Schroeder C B, Leemans W P. Physics of laser-driven plasma-based electron accelerators[J]. Reviews of Modern Physics, 2009, 81(3): 1229-1285. doi: 10.1103/RevModPhys.81.1229 [11] 陈民, 刘峰, 李博原, 等. 激光等离子体尾波加速器的发展和展望[J]. 强激光与粒子束, 2020, 32:092001Chen Min, Liu Feng, Li Boyuan, et al. Development and prospect of laser plasma wakefield accelerator[J]. High Power Laser and Particle Beams, 2020, 32: 092001 [12] Aniculaesei C, Ha T, Yoffe S, et al. The acceleration of a high-charge electron bunch to 10 GeV in a 10-cm nanoparticle-assisted wakefield accelerator[J]. Matter and Radiation at Extremes, 2024, 9: 014001. doi: 10.1063/5.0161687 [13] Götzfried J, Döpp A, Gilljohann M F, et al. Physics of high-charge electron beams in laser-plasma wakefields[J]. Physical Review X, 2020, 10: 041015. [14] Cipiccia S, Islam M R, Ersfeld B, et al. Gamma-rays from harmonically resonant betatron oscillations in a plasma wake[J]. Nature Physics, 2011, 7(11): 867-871. doi: 10.1038/nphys2090 [15] Danson C N, Haefner C, Bromage J, et al. Petawatt and exawatt class lasers worldwide[J]. High Power Laser Science and Engineering, 2019, 7: e54. doi: 10.1017/hpl.2019.36 [16] 冷雨欣. 上海超强超短激光实验装置[J]. 中国激光, 2019, 46:0100001 doi: 10.3788/CJL201946.0100001Leng Yuxin. Shanghai superintense ultrafast laser facility[J]. Chinese Journal of Lasers, 2019, 46: 0100001 doi: 10.3788/CJL201946.0100001 [17] Zeng Xiaoming, Zhou Kainan, Zuo Yanlei, et al. Multi-petawatt laser facility fully based on optical parametric chirped-pulse amplification[J]. Optics Letters, 2017, 42(10): 2014-2017. doi: 10.1364/OL.42.002014 [18] Cikhardt J, Gyrdymov M, Zähter S, et al. Characterization of bright betatron radiation generated by direct laser acceleration of electrons in plasma of near critical density[J]. Matter and Radiation at Extremes, 2024, 9: 027201. doi: 10.1063/5.0181119 [19] Tan J H, Li Y F, Li D Z, et al. Observation of high efficiency Betatron radiation from femtosecond petawatt laser irradiated near critical plasmas[DB/OL]. arXiv preprint arXiv: 2109.12467, 2021. [20] Zhang Z M, Wu Y C, Zhang X H, et al. Inhibition of electron refluxing in laser-gas interactions for enhanced positron generation[J]. Plasma Physics and Controlled Fusion, 2022, 64: 095015. doi: 10.1088/1361-6587/ac7ee9 [21] Ammosov M V, Delone N B, Krainov V P. Tunnel ionization of complex atoms and atomic ions in electromagnetic field[C]//Proceedings of SPIE 0664, High Intensity Laser Processes. 1986: 138-141. [22] Chen Min, Pukhov A, Yu Tongpu, et al. Radiation reaction effects on ion acceleration in laser foil interaction[J]. Plasma Physics and Controlled Fusion, 2011, 53: 014004. doi: 10.1088/0741-3335/53/1/014004 [23] Gahn C, Tsakiris G D, Pukhov A, et al. Multi-MeV electron beam generation by direct laser acceleration in high-density plasma channels[J]. Physical Review Letters, 1999, 83(23): 4772-4775. doi: 10.1103/PhysRevLett.83.4772 [24] Pukhov A, Sheng Z M, Meyer-ter-Vehn J. Particle acceleration in relativistic laser channels[J]. Physics of Plasmas, 1999, 6(7): 2847-2854. doi: 10.1063/1.873242 [25] Lu W, Tzoufras M, Joshi C, et al. Generating multi-GeV electron bunches using single stage laser wakefield acceleration in a 3D nonlinear regime[J]. Physical Review Special Topics-Accelerators and Beams, 2007, 10: 061301. doi: 10.1103/PhysRevSTAB.10.061301 [26] Esarey E, Shadwick B A, Catravas P, et al. Synchrotron radiation from electron beams in plasma-focusing channels[J]. Physical Review E, 2002, 65: 056505. doi: 10.1103/PhysRevE.65.056505 -
下载:
点击查看大图
图(6)
计量
- 文章访问数: 50
- HTML全文浏览量: 27
- PDF下载量: 1
- 被引次数: 0
