Abstract
Keywords
1 Introduction
Bright X/γ-ray sources have various applications in the laboratory astrophysics, nuclear photonics, ultra-high-density matter radiography, high-flux positron generation, and nuclear medical imaging[1–6]. Hard X/γ-rays are conventionally produced by large synchrotron facilities with peak brilliance in the range of
Vortex photon beams have drawn wide attention recently spread over the microhertz to megaelectronvolt–gigaelectronvolt γ-ray frequency ranges, due to their potential use in microscopy imaging[21], microscopic particle control[22], and astrophysics[23,24]. As a unique tool, they are also of significance to gain insight into the dynamics of particles. The interaction of matter and photons via the AM may play an important role in the evolution of matter in the universe. There have been some discussions about the possible role of vortex photons in astrophysics[24,25], and it has been argued that vortex photons are generated in several astrophysical environments such as around Kerr black holes[23] and in nonuniform plasmas[26]. With an additional degree of freedom, vortex photons can also carry more information concerning the physical circumstances of their sources, e.g., the magnetic field and radiation field[27]. A vortex laser pulse, e.g., Laguerre–Gaussian (LG) laser, has a helical phase front, hollow transverse field distribution, and strong longitudinal electric field[28–47], enabling the generation of energetic charged particles with orbital angular momentum (OAM)[33–42,48], high OAM X/γ-ray[43,49] emission and harmonics generation[44,45,50]. To the best of our knowledge, the highest intensity of LG laser pulse achieved experimentally is around 1020 W/cm2 with total power of tens of terawatts (TW)[32,51]. Recently, some efforts have been steadily dedicated to generating X/γ-ray[52–59] vortices by use of vortex lasers. However, PW-class vortex laser pulses with an intensity of 1022 W/cm2 are typically required, which pose great challenges to current laser technology.
In this paper, we present an all-optical plasma-based scheme to produce a well-directed multi-MeV γ-ray vortex beam with large beam angular momentum (BAM) and high brilliance. In the scheme, a circularly polarized (CP) Gaussian laser pulse irradiates a micro-channel target in the first stage, and a large number of electrons are dragged out from the channel wall. These electrons are accelerated subsequently to hundreds of MeV by the longitudinal electric fields in the channel. Meanwhile, the drive laser transfers its spin angular momentum (SAM) to the energetic electrons’ OAM, so that a dense electron beam with large AM is formed. In the second stage, the drive pulse is reflected from the attached fan-foil[28], which adds exp(ilϕ) to the phase of the drive and changes it to an LG one. Once the energetic electrons collide head-on with the reflected vortex laser, the nonlinear Compton scattering (NCS) is triggered with a large key quantum parameter
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2 Results and discussion
2.1 Overview of the scheme and model
Figure 1 illustrates schematically our scheme and the key features of the produced γ-photon beams. In order to demonstrate the proposed scheme, we performed full three-dimensional particle-in-cell (3D-PIC) simulations with the open-source code EPOCH. In the code, the QED BLOCK is enabled to include the emission of photons via a Monte Carlo algorithm, the radiation reaction effect, and the feedback between the plasma and photon-emission processes, whereas the effect of spin polarization is ignored[60,61]. In the first stage, a left-handed CP Gaussian laser pulse with the dimensionless laser electric field amplitude
Figure 1.Schematic of γ-ray vortex generation from a laser-illuminated light-fan-in-channel target. A CP laser pulse is incident from the left and irradiates a micro-channel target. Electrons are extracted from the channel wall, travel along the channel, and are accelerated to hundreds of MeV by the longitudinal electric fields. Later, the laser pulse is reflected along the –
2.2 Electron acceleration in the micro-channel
Micro-channel targets have been widely employed to reshape the laser profile and enhance electron and ion acceleration[68,70,71]. They can act as a unique source of well-defined electron bunches and have potential applications in bright X/γ-photon emission. Assuming a CP plane wave in the form of
which is obviously much smaller relative to the laser transverse electric field. As for the laser parameters used in our simulations, the amplitude of the longitudinal laser electric field is only about 0.03
Figure 2.Distributions of the transverse electric field
where
Figure 3.(a) Three-dimensional isosurface distribution of electron energy density of 60 MeV at . The (
Figure 2 presents the transverse electric field Ey and electron distribution in the y–z plane ranging from
In order to investigate the electron acceleration inside the micro-channel, we track some typical electrons (energy above 100 MeV at
2.3 Laser pulse reflection by the light fan
As the laser pulse propagates in the channel and arrives at the fan-foil attached to the channel, the second stage starts. Here, the thickness of the fan-foil increases with the angle ϕ in the cylindrical coordinate system, as illustrated in Figure 1. When the laser irradiates the fan-foil, the reflected laser wave at different angle ϕ has different phase change, resulting in an LG pulse generation. LG laser can carry OAM, which can improve the BAM of γ-ray and the conversion efficiency of laser- γ-ray AM. We will discuss this point later. Figure 4 shows the laser transverse electric field Ey in the y-z plane at different positions between
Figure 4.Distributions of the transverse electric field
where
Here
2.4 Bright γ-ray vortex emission
At the third stage, the reflected LG laser pulse collides head-on with the energetic electrons with large AM. Here, the stochastic emission model is employed and implemented in the EPOCH code using a probabilistic Monte Carlo algorithm. The QED emission rates are determined by the Lorentz-invariant parameter[73]:
Figure 5.(a) Distributions of along the
Figure 5(b) shows the 3D isosurface distribution of the number density of emitted
Figure 6(a) presents the evolution of energy spectra of the
Figure 6.(a) Energy spectra of
2.5 AM transfer from laser to
Exploring the laser AM transfer to charged particles and photons is of significance for understanding the dynamics of laser–plasma interaction at high laser intensity. When a laser beam carrying nonzero AM impinges on plasma, its AM can be transferred to plasma ions and electrons, thus setting them in rotational motion. This occurs both with SAM and OAM. As we know, each photon carries
where
Here the subscript i denotes the serial number of individual particles. The photons’ momentum originates from the parent electrons, the averaged momentum can be scaled as[77]
Figure 7.(a) Evolution of BAM of electrons (black arrow), protons (blue arrow), carbon ions (green arrow), and -photons (red arrow). (b) Evolution of laser energy conversion efficiency to electrons (black arrow), protons (blue arrow), carbon ions (green arrow), and -protons (red arrow). Here the gray area denotes the collision stage and the arrows indicate the
3 Discussion
In order to demonstrate that the light fan is capable of increasing the laser photon’s AM, a plane foil and a right-hand helix foil (RH fan) are considered separately in our additional PIC simulations. The differences can be easily distinguished from each photon’s AM during the laser–foil interaction. For a laser pulse, its total electromagnetic energy is
where
Figure 8.Evolution of (a) averaged AM of laser photons and (b) averaged BAM of -photons in the right-handed helix fan case (RH fan, black), plane foil case (blue), and left-handed helix fan case (LF fan, red). The gray area shows the collision stage.
Figure 8(b) illustrates the evolution of averaged BAM of
We also investigated the robustness of the scheme by using different laser and plasma parameters. First, we discuss the effect of the laser intensity, where we keep all other parameters unchanged but vary the normalized laser amplitude from
Figure 9.Scaling of the photon yield (, black circles), the laser energy conversion efficiency (, red circles), and total -photon BAM (, blue circles) with (a) the laser electric field amplitude and (b) the micro-channel length . Here, the black and blue curves are the fitting results.
We also considered the effect of the length of micro-channel on the photon emission. Figure 9(b) shows the simulation results for which l is varied in the range of
4 Conclusion
In conclusion, we have proposed and numerically demonstrated an all-optical laser–plasma scheme to produce multi-MeV
References
[1] Y. Eisen, A. Shor, I. Mardor. Nucl. Instrum. Methods Phys. Res. Sect. A Accel. Spectrom. Detect. Assoc. Equip., 428, 158(1999).
[2] J. Ganz. Gamma Knife Neurosurgery(2011).
[3] T. Brabec, F. Krausz. Rev. Modern Phys., 72, 545(2000).
[4] S. V. Bulanov, T. Z. Esirkepov, M. Kando, J. Koga, K. Kondo, G. Korn. Plasma Phys. Rep., 41, 1(2015).
[5] D. Habs, M. M. Günther, M. Jentschel, P. G. Thirolf. AIP Conf. Proc., 1462, 177(2012).
[6] O. Renner, F. B. Rosmej. Matter Radiat. Extremes, 4, 024201(2019).
[7] R. W. Schoenlein, W. P. Leemans, A. H. Chin, P. Volfbeyn, T. E. Glover, P. Balling, M. Zolotorev, K. J. Kim, S. Chattopadhyay, C. V. Shank. Astrophys. J., 274, 4(2003).
[8] K. T. Phuoc, S. Corde, C. Thaury, V. Malka, A. Tafzi, J. P. Goddet, R. C. Shah, S. Sebban, A. Rousse. Nat. Photon., 6, 308(2012).
[9] C. Yu, R. Qi, W. Wang, J. Liu, W. Li, C. Wang, Z. Zhang, J. Liu, Z. Qin, M. Fang, K. Feng, Y. Wu, Y. Tian, Y. Xu, F. Wu, Y. Leng, X. Weng, J. Wang, F. Wei, Y. Yi, Z. Song, R. Li, Z. Xu. Sci. Rep., 6, 29518(2016).
[10] S. Cipiccia, M. R. Islam, B. Ersfeld, R. P. Shanks, E. Brunetti, G. Vieux, X. Yang, R. C. Issac, S. M. Wiggins, G. H. Welsh, M. P. Anania, D. Maneuski, R. Montgomery, G. Smith, M. Hoek, D. J. Hamilton, N. R.C. Lemos, D. Symes, P. P. Rajeev, V. O. Shea, J. M. Dias, D. A. Jaroszynski. Nat. Phys., 7, 867(2011).
[11] N. D. Powers, I. Ghebregziabher, G. Golovin, C. Liu, S. Chen, S. Banerjee, J. Zhang, D. P. Umstadter. Nat. Photon., 8, 28(2014).
[12] S. Chen, N. D. Powers, I. Ghebregziabher, C. M. Maharjan, C. Liu, G. Golovin, S. Banerjee, J. Zhang, N. Cunningham, A. Moorti, S. Clarke, S. Pozzi, D. P. Umstadter. Phys. Rev. Lett., 110, 155003(2013).
[13] W. M. Wang, Z. M. Sheng, P. Gibbon, L. M. Chen, Y. T. Li, J. Zhang. Proc. Natl. Acad. Sci. USA, 115, 9911(2018).
[14] X.-L. Zhu, M. Chen, T.-P. Yu, S.-M. Weng, F. He, Z.-M. Sheng. Matter Radiat. Extremes, 4, 014401(2019).
[15] D. J. Stark, T. Toncian, A. V. Arefiev. Phys. Rev. Lett., 116, 185003(2016).
[16] Y.-J. Gu, M. Jirka, O. Klimo, S. Weber. Matter Radiat. Extremes, 4, 064403(2019).
[17] J. Wang, X. B. Li, L. F. Gan, Y. Xie, C. L. Zhong, C. T. Zhou, S. P. Zhu, X. T. He. Phys. Rev. Appl., 14, 014094(2020).
[18] Y. Lu, G.-B. Zhang, J. Zhao, Y.-T. Hu, H. Zhang, D.-A. Li, Q.-N. Li, Y. Cao, Y.-B. Wu, Y. Yin, F.-Q. Shao, T.-P. Yu. Opt. Express, 29, 8926(2021).
[19] T. P. Yu, A. Pukhov, Z. M. Sheng, F. Liu, G. Shvets. Phys. Rev. Lett., 110, 045001(2013).
[20] T. P. Yu, L. X. Hu, Y. Yin, F. Q. Shao, H. B. Zhuo, Y. Y. Ma, X. H. Yang, W. Luo, A. Pukhov. Appl. Phys. Lett., 105, 114101(2014).
[21] S. Fürhapter, A. Jesacher, S. Bernet, M. Ritsch-Marte. Opt. Express, 13, 689(2005).
[22] M. F. Andersen, C. Ryu, P. Cladé, V. Natarajan, A. Vaziri, K. Helmerson, W. D. Phillips. Phys. Rev. Lett., 97, 170406(2006).
[23] F. Tamburini, B. Thidé, G. Molina-Terriza, G. Anzolin. Nat. Phys., 7, 195(2011).
[24] M. Harwit. Astrophys. J., 597, 1266(2003).
[25] N. M. Elias. Astron. Astrophys., 492, 883(2008).
[26] F. Tamburini, A. Sponselli, B. Thidé, J. T. Mendonça. EPL, 90, 1303(2010).
[27] Y. Taira, M. Katoh. Astrophys. J., 860, 45(2018).
[28] Y. Shi, B. Shen, L. Zhang, X. Zhang, W. Wang, Z. Xu. Phys. Rev. Lett., 112, 235001(2014).
[29] W. Gong, B. Shen, L. Zhang, X. Zhang. New J. Phys., 21, 43022(2019).
[30] J. Vieira, R. M. G. M. Trines, E. P. Alves, R. A. Fonseca, J. T. Mendonça, R. Bingham, P. Norreys, L. O. Silva. Nat. Commun., 7, 10371(2016).
[31] G. Lehmann, K. H. Spatschek. Phys. Rev. Lett., 116, 225002(2016).
[32] A. Leblanc, A. Denoeud, L. Chopineau, G. Mennerat, P. Martin, F. Quéré. Nat. Phys., 13, 440(2017).
[33] X. Zhang, B. Shen, L. Zhang, J. Xu, X. Wang, W. Wang, L. Yi, Y. Shi. New J. Phys., 16, 123051(2014).
[34] J. Vieira, J. T. Mendonça. Phys. Rev. Lett., 112, 215001(2014).
[35] Y. Shi, J. Vieira, R. M. G. M. Trines, R. Bingham, B. F. Shen, R. J. Kingham. Phys. Rev. Lett., 121, 145002(2018).
[36] C. Baumann, A. Pukhov. Phys. Plasmas, 25, 083114(2018).
[37] L. X. Hu, T. P. Yu, H. Z. Li, Y. Yin, P. McKenna, F. Q. Shao. Opt. Lett., 43, 2615(2018).
[38] L. X. Hu, T. P. Yu, Z. M. Sheng, J. Vieira, D. B. Zou, Y. Yin, P. McKenna, F. Q. Shao. Sci. Rep., 8, 7282(2018).
[39] W. Wang, B. Shen, X. Zhang, L. Zhang, Y. Shi, Z. Xu. Sci. Rep., 5, 8274(2015).
[40] G. B. Zhang, M. Chen, C. B. Schroeder, J. Luo, M. Zeng, F. Y. Li, L. L. Yu, S. M. Weng, Y. Y. Ma, T. P. Yu, Z. M. Sheng, E. Esarey. Phys. Plasmas, 23, 033114(2016).
[41] G. B. Zhang, M. Chen, J. Luo, M. Zeng, T. Yuan, J. Y. Yu, Y. Y. Ma, T. P. Yu, L. L. Yu, S. M. Weng, Z. M. Sheng. J. Appl. Phys., 119, 103101(2016).
[42] W. P. Wang, C. Jiang, B. F. Shen, F. Yuan, Z. M. Gan, H. Zhang, S. H. Zhai, Z. Z. Xu. Phys. Rev. Lett., 122, 024801(2019).
[43] E. Hemsing, A. Marinelli. Phys. Rev. Lett., 109, 224801(2012).
[44] E. Hemsing, A. Knyazik, M. Dunning, D. Xiang, A. Marinelli, C. Hast, J. B. Rosenzweig. Nat. Phys., 9, 549(2013).
[45] X. Zhang, B. Shen, Y. Shi, X. Wang, L. Zhang, W. Wang, J. Xu, L. Yi, Z. Xu. Phys. Rev. Lett., 114, 173901(2015).
[46] Y.-T. Hu, J. Zhao, H. Zhang, Y. Lu, W.-Q. Wang, L.-X. Hu, F.-Q. Shao, T.-P. Yu. Appl. Phys. Lett., 118, 054101(2021).
[47] H. Zhang, G. B. Zhang, D. B. Zou, L. X. Hu, H. Y. Zhou, W. Q. Wang, X. R. Xu, K. Liu, Y. Yin, H. B. Zhuo, F. Q. Shao, T. P. Yu. Phys. Plasmas, 27, 053105(2020).
[48] L. B. Ju, C. T. Zhou, K. Jiang, T. W. Huang, H. Zhang, T. X. Cai, J. M. Cao, B. Qiao, S. C. Ruan. New J. Phys., 20, 063004(2018).
[49] Y.-Y. Chen, K. Z. Hatsagortsyan, C. H. Keitel. Matter Radiat. Extremes, 4, 024401(2019).
[50] J. W. Wang, M. Zepf, S. G. Rykovanov. Nat. Commun., 10, 5554(2019).
[51] W. P. Wang, C. Jiang, H. Dong, X. M. Lu, Z. Z. Xu. Phys. Rev. Lett., 125, 034801(2020).
[52] X. L. Zhu, T. P. Yu, M. Chen, S. M. Weng, Z. M. Sheng. New J. Phys., 20, 83013(2018).
[53] L. B. Ju, C. T. Zhou, T. W. Huang, K. Jiang, C. N. Wu, T. Y. Long, L. Li, H. Zhang, M. Y. Yu, S. C. Ruan. Phys. Rev. Appl., 12, 014054(2019).
[54] C. Liu, B. Shen, X. Zhang, Y. Shi, L. Ji, W. Wang, L. Yi, L. Zhang, T. Xu, Z. Pei, Z. Xu. Phys. Plasmas, 23, 093120(2016).
[55] Y. Y. Liu, Y. I. Salamin, Z. K. Dou, Z. F. Xu, J. X. Li. Opt. Lett., 45, 395(2020).
[56] Y. Y. Chen, J. X. Li, K. Z. Hatsagortsyan, C. H. Keitel. Phys. Rev. Lett., 121, 74801(2018).
[57] M. Katoh, M. Fujimoto, H. Kawaguchi, K. Tsuchiya, K. Ohmi, T. Kaneyasu, Y. Taira, M. Hosaka, A. Mochihashi, Y. Takashima. Phys. Rev. Lett., 118, 094801(2017).
[58] V. Petrillo, G. Dattoli, I. Drebot, F. Nguyen. Phys. Rev. Lett., 117, 123903(2016).
[59] U. D. Jentschura, V. G. Serbo. Phys. Rev. Lett., 106, 013001(2011).
[60] B. King, N. Elkina, H. Ruhl. Phys. Rev. A, 87, 042117(2013).
[61] D. D. Sorbo, D. Seipt, T. G. Blackburn, A. G. R. Thomas, C. D. Murphy, J. G. Kirk, C. P. Ridgers. Phys. Rev. A, 96, 043407(2017).
[62] G. A. Mourou, G. Korn, W. Sandner, J. L. Collier. ELI - Extreme Light Infrastructure White Book(2011).
[63] D. N. Papadopoulos, J. P. Zou, C. L. Blanc, G. Chériaux, P. Georges, F. Druon, G. Mennerat, P. Ramirez, L. Martin, A. Fréneaux, A. Beluze, N. Lebas, P. Monot, F. Mathieu, P. Audebert. High Power Laser Sci. Eng, 4(2016).
[64] W. Li, Z. Gan, L. Yu, C. Wang, Y. Liu, Z. Guo, L. Xu, M. Xu, Y. Hang, Y. Xu, J. Wang, P. Huang, H. Cao, B. Yao, X. Zhang, L. Chen, Y. Tang, S. Li, X. Liu, S. Li, M. He, D. Yin, X. Liang, Y. Leng, R. Li, Z. Xu. Opt. Lett., 43, 5681(2018).
[65] G. Doumy, F. Quéré, O. Gobert, M. Perdrix, P. Martin, P. Audebert, J. C. Gauthier, J.-P. Geindre, T. Wittmann. Phys. Rev. E, 69, 026402(2004).
[66] A Lévy, T. Ceccotti, P. D’Oliveira, F. Réau, M. Perdrix, F. Quéré, P. Monot, M. Bougeard, H. Lagadec, P. Martin, J.-P. Geindre, P. Audebert. Opt. Lett., 32, 310(2007).
[67] B. Dromey, S. Kar, M. Zepf, P. Foster. Rev. Sci. Instrum., 75, 645(2004).
[68] J. Snyder, L. L. Ji, K. M. George, C. Willis, G. E. Cochran, R. L. Daskalova, A. Handler, T. Rubin, P. L. Poole, D. Nasir, A. Zingale, E. Chowdhury, B. F. Shen, D. W. Schumacher. Phys. Plasmas, 26, 033110(2019).
[69] M. A. Purvis, V. N. Shlyaptsev, R. Hollinger, C. Bargsten, A. Pukhov, A. Prieto, Y. Wang, B. M. Luther, L. Yin, S. Wang, J. J. Rocca. Nat. Photon., 7, 796(2013).
[70] K. D. Xiao, T. W. Huang, L. B. Ju, R. Li, S. L. Yang, Y. C. Yang, S. Z. Wu, H. Zhang, B. Qiao, S. C. Ruan, C. T. Zhou, X. T. He. Phys. Rev. E, 93, 043207(2016).
[71] D. Y. Yu, D. B. Zou, M. Y. Yu, T. P. Yu, Y. Yin, F. Q. Shao, H. B. Zhuo, C. T. Zhou, S. C. Ruan. New J. Phys., 21, 083003(2019).
[72] M. W. Beijersbergen, R. P. C. Coerwinkel, M. Kristensen, J. P. Woerdman. Opt. Angular Moment., 112, 179(2016).
[73] V. I. Ritus. Quantum Effects of the Interaction of Elementary Particles with an Intense Electromagnetic Field(1985).
[74] A. R. Bell, J. G. Kirk. Phys. Rev. Lett., 101, 200403(2008).
[75] J. G. Kirk, A. R. Bell, I. Arka. Plasma Phys. Control. Fusion, 51, 085008(2009).
[76] M. J. Duff, R. Capdessus, D. Del Sorbo, C. P. Ridgers, M. King, P. McKenna. Plasma Phys. Control. Fusion, 60, 064006(2018).
[77] X. L. Zhu, M. Chen, T. P. Yu, S. M. Weng, L. X. Hu, P. McKenna, Z. M. Sheng. Appl. Phys. Lett., 112, 174102(2018).
[78] B. Feng, C. Y. Qin, X. S. Geng, Q. Yu, W. Q. Wang, Y. T. Wu, X. Yan, L. L. Ji, B. F. Shen. Sci. Rep., 9, 18780(2019).
[79] I. P. Ivanov. Phys. Rev. D, 83, 093001(2011).
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