- Physical Review Journals
All JournalsPhysics Magazine

Physical Review Letters

Reuse & Permissions

It is not necessary to obtain permission to reuse this article or its components as it is available under the terms of the Creative Commons Attribution 4.0 International license. This license permits unrestricted use, distribution, and reproduction in any medium, provided attribution to the author(s) and the published article's title, journal citation, and DOI are maintained. Please note that some figures may have been included with permission from other third parties. It is your responsibility to obtain the proper permission from the rights holder directly for these figures.

Export citation

Export citation

Choose format for download:

Download Citation
  • Open Access

High-Flux X-Ray Emission due to Injection into a Laser-Wakefield Accelerator beyond Its Depletion Length

J. C. Wood1,*, K. Põder1, N. C. Lopes1,2, J. M. Cole1, S. Alatabi1, A. J. Hughes1, P. Foster3, C. Kamperidis1, O. Kononenko4 et al.

S. P. D. Mangles1, D. Neely3,†, C. A. J. Palmer4, D. R. Rusby3, G. Sarri5, M. J. V. Streeter1, D. R. Symes3, J. R. Warwick5, and Z. Najmudin1,‡

  • *Contact author: jonathan.wood@desy.de
  • †Deceased.
  • ‡Contact author: z.najmudin@imperial.ac.uk
PDF

Phys. Rev. Lett. 137, 105001 – Published 3 September, 2026

DOI: https://doi.org/10.1103/krsl-322s

Abstract

Laser wakefield accelerators are bright, compact sources of synchrotronlike x-rays. By driving the wakefield using a 110 TW laser in a variable length gas cell, we are able to map the evolution of the electron beam and resulting x-ray emission. We find that using a laser pulse initially focused to larger than the matched spot size and extending the plasma length beyond the depletion length, dramatically increases the x-ray flux. Self-injected electrons are initially accelerated to >2  GeV, emitting x-rays with critical energy Ec>20  keV. But, as these electrons dephase, a second high-charge electron bunch is produced and accelerated to ≈ 0.7  GeV. The x-rays produced by this bunch dominate the total emission with >5×1010 photons per shot with Ec=12–17  keV and a flux of 7×104  photons/mrad2/0.1%BW. Combining electron and x-ray measurements reveals that the increased emission results from the larger betatron amplitude of the secondary bunch. Simulations attribute this to rapid bubble expansion driven by laser compression over the depletion length, which leads to injection of a high-charge electron bunch with increased transverse momentum and thus stronger betatron radiation.

View figure in article

Physics Subject Headings (PhySH)

Article Text

Supplemental Material

References (82)

  1. J. P. Marangos, Phil. Trans. R. Soc. A 377, 20170481 (2019).
  2. M. D. Perry, J. A. Sefcik, T. Cowan, S. Hatchett, A. Hunt, M. Moran, D. Pennington, R. Snavely, and S. C. Wilks, Rev. Sci. Instrum. 70, 265 (1999).
  3. C. Reich, P. Gibbon, I. Uschmann, and E. Förster, Phys. Rev. Lett. 84, 4846 (2000).
  4. R. D. Edwards, M. A. Sinclair, T. J. Goldsack, K. Krushelnick, F. N. Beg, E. L. Clark, A. E. Dangor, Z. Najmudin, M. Tatarakis, B. Walton, M. Zepf, K. W. D. Ledingham, I. Spencer, P. A. Norreys, R. J. Clarke, R. Kodama, Y. Toyama, and M. Tampo, Appl. Phys. Lett. 80, 2129 (2002).
  5. C. M. Brenner, S. R. Mirfayzi, D. R. Rusby, C. Armstrong, A. Alejo, L. A. Wilson, R. Clarke, H. Ahmed, N. M. H. Butler, D. Haddock, A. Higginson, A. McClymont, C. Murphy, M. Notley, P. Oliver, R. Allott, C. Hernandez-Gomez, S. Kar, P. McKenna, and D. Neely, Plasma Phys. Controlled Fusion 58, 014039 (2015).
  6. M. Ferray, A. L’Huillier, X. F. Li, L. A. Lompre, G. Mainfray, and C. Manus, J. Phys. B 21, L31 (1988).
  7. X. F. Li, A. L’Huillier, M. Ferray, L. A. Lompré, and G. Mainfray, Phys. Rev. A 39, 5751 (1989).
  8. J. Seres, E. Seres, A. J. Verhoef, G. Tempea, C. Streli, P. Wobrauschek, V. Yakovlev, A. Scrinzi, C. Spielmann, and F. Krausz, Nature (London) 433, 596 (2005).
  9. B. Dromey, S. Kar, C. Bellei, D. C. Carroll, R. J. Clarke, J. S. Green, S. Kneip, K. Markey, S. R. Nagel, P. T. Simpson, L. Willingale, P. McKenna, D. Neely, Z. Najmudin, K. Krushelnick, P. A. Norreys, and M. Zepf, Phys. Rev. Lett. 99, 085001 (2007).
  10. W. J. Brown, S. G. Anderson, C. P. J. Barty, S. M. Betts, R. Booth, J. K. Crane, R. R. Cross, D. N. Fittinghoff, D. J. Gibson, F. V. Hartemann, E. P. Hartouni, J. Kuba, G. P. Le Sage, D. R. Slaughter, A. M. Tremaine, A. J. Wootton, P. T. Springer, and J. B. Rosenzweig, Phys. Rev. ST Accel. Beams 7, 060702 (2004).
  11. S. G. Rykovanov, C. G. R. Geddes, J.-L. Vay, C. B. Schroeder, E. Esarey, and W. P. Leemans, J. Phys. B 47, 234013 (2014).
  12. H. Schwoerer, B. Liesfeld, H.-P. Schlenvoigt, K.-U. Amthor, and R. Sauerbrey, Phys. Rev. Lett. 96, 014802 (2006).
  13. N. D. Powers, I. Ghebregziabher, G. Golovin, C. Liu, S. Chen, S. Banerjee, and D. P. Umstadter, Nat. Photonics 8, 28 (2014).
  14. K. T. Phuoc, S. Corde, C. Thaury, V. Malka, A. Tafzi, J. P. Goddet, R. C. Shah, S. Sebban, and A. Rousse, Nat. Photonics 6, 308 (2012).
  15. T. Tajima and J. M. Dawson, Phys. Rev. Lett. 43, 267 (1979).
  16. E. Esarey, C. B. Schroeder, and W. P. Leemans, Rev. Mod. Phys. 81, 1229 (2009).
  17. A. Pukhov and J. Meyer-ter Vehn, Appl. Phys. B Lasers Opt. 74, 355 (2002).
  18. W. Lu, C. Huang, M. Zhou, W. B. Mori, and T. Katsouleas, Phys. Rev. Lett. 96, 165002 (2006).
  19. S. Kneip et al., Phys. Rev. Lett. 103, 035002 (2009).
  20. H. T. Kim, K. H. Pae, H. J. Cha, I. J. Kim, T. J. Yu, J. H. Sung, S. K. Lee, T. M. Jeong, and J. Lee, Phys. Rev. Lett. 111, 165002 (2013).
  21. X. Wang et al., Nat. Commun. 4, 1988 (2013).
  22. W. P. Leemans, A. J. Gonsalves, H.-S. Mao, K. Nakamura, C. Benedetti, C. B. Schroeder, C. Tóth, J. Daniels, D. E. Mittelberger, S. S. Bulanov, J.-L. Vay, C. G. R. Geddes, and E. Esarey, Phys. Rev. Lett. 113, 245002 (2014).
  23. A. J. Gonsalves et al., Phys. Rev. Lett. 122, 084801 (2019).
  24. S. Wang, C. E. Clayton, B. E. Blue, E. S. Dodd, K. A. Marsh, W. B. Mori, C. Joshi, S. Lee, P. Muggli, T. Katsouleas, F. J. Decker, M. J. Hogan, R. H. Iverson, P. Raimondi, D. Walz, R. Siemann, and R. Assmann, Phys. Rev. Lett. 88, 135004 (2002).
  25. A. Rousse, K. T. Phuoc, R. Shah, A. Pukhov, E. Lefebvre, V. Malka, S. Kiselev, F. Burgy, J.-P. Rousseau, D. Umstadter, and D. Hulin, Phys. Rev. Lett. 93, 135005 (2004).
  26. S. Kneip et al., Nat. Phys. 6, 980 (2010).
  27. S. Corde, K. Ta Phuoc, G. Lambert, R. Fitour, V. Malka, A. Rousse, A. Beck, and E. Lefebvre, Rev. Mod. Phys. 85, 1 (2013).
  28. J. M. Cole, J. C. Wood, N. C. Lopes, K. Poder, R. L. Abel, S. Alatabi, J. S. J. Bryant, A. Jin, S. Kneip, K. Mecseki, D. R. Symes, S. P. D. Mangles, and Z. Najmudin, Sci. Rep. 5, 13244 (2015).
  29. M. S. Bloom, M. J. V. Streeter, S. Kneip, R. A. Bendoyro, O. Cheklov, J. M. Cole, A. Döpp, C. J. Hooker, J. Holloway, J. Jiang, N. C. Lopes, H. Nakamura, P. A. Norreys, P. P. Rajeev, D. R. Symes, J. Schreiber, J. C. Wood, M. Wing, Z. Najmudin, and S. P. D. Mangles, Phys. Rev. Accel. Beams 23, 061301 (2020).
  30. K. T. Phuoc, S. Corde, R. Fitour, R. Shah, F. Albert, J.-P. Rousseau, F. Burgy, A. Rousse, V. Seredov, and A. Pukhov, Phys. Plasmas 15, 073106 (2008).
  31. F. Albert, K. T. Phuoc, R. Shah, S. Corde, R. Fitour, A. Tafzi, F. Burgy, D. Douillet, T. Lefrou, and A. Rousse, Plasma Phys. Controlled Fusion 50, 124008 (2008).
  32. K. T. Phuoc, R. Fitour, A. Tafzi, T. Garl, N. Artemiev, R. Shah, F. Albert, D. Boschetto, A. Rousse, D.-E. Kim, A. Pukhov, V. Seredov, and I. Kostyukov, Phys. Plasmas 14, 080701 (2007).
  33. S. Kneip, C. McGuffey, F. Dollar, M. S. Bloom, V. Chvykov, G. Kalintchenko, K. Krushelnick, A. Maksimchuk, S. P. D. Mangles, T. Matsuoka, Z. Najmudin, C. A. J. Palmer, J. Schreiber, W. Schumaker, A. G. R. Thomas, and V. Yanovsky, Appl. Phys. Lett. 99, 093701 (2011).
  34. S. Fourmaux, S. Corde, K. T. Phuoc, P. Lassonde, G. Lebrun, S. Payeur, F. Martin, S. Sebban, V. Malka, A. Rousse, and J. C. Kieffer, Opt. Lett. 36, 2426 (2011).
  35. J. Wenz, S. Schleede, K. Khrennikov, M. Bech, P. Thibault, M. Heigoldt, F. Pfeiffer, and S. Karsch, Nat. Commun. 6, 7568 (2015).
  36. J. M. Cole et al., Proc. Natl. Acad. Sci. U.S.A. 115, 6335 (2018).
  37. A. Döpp, L. Hehn, J. Götzfried, J. Wenz, M. Gilljohann, H. Ding, S. Schindler, F. Pfeiffer, and S. Karsch, Optica 5, 199 (2018).
  38. A. E. Hussein et al., Sci. Rep. 9, 3249 (2019).
  39. J.-N. Gruse et al., Nucl. Instrum. Methods Phys. Res., Sect. A 983, 164369 (2020).
  40. D. Guénot, K. Svendsen, J. B. Svensson, H. Ekerfelt, A. Persson, O. Lundh, and E. Berrocal, Optica 7, 131 (2020).
  41. A. Doherty, S. Fourmaux, R. Astolfo, A. amd Ziesche, J. Wood, O. Finlay, W. Stolp, D. Batey, I. Manke, F. Légaré, M. Boone, D. Symes, Z. Najmudin, M. Endrizzi, A. Olivo, and S. Cipiccia, Commun. Phys. 6, 288 (2023).
  42. J. C. Wood et al., Sci. Rep. 8, 11010 (2018).
  43. F. Albert and A. G. R. Thomas, Plasma Phys. Controlled Fusion 58, 103001 (2016).
  44. M. Šmíd, I. Gallardo González, H. Ekerfelt, J. Björklund Svensson, M. Hansson, J. C. Wood, A. Persson, S. P. D. Mangles, O. Lundh, and K. Falk, Rev. Sci. Instrum. 88, 063102 (2017).
  45. B. Mahieu, N. Jourdain, K. Ta Phuoc, F. Dorchies, J. P. Goddet, A. Lifschitz, P. Renaudin, and L. Lecherbourg, Nat. Commun. 9, 3276 (2018).
  46. B. Kettle et al., Phys. Rev. Lett. 123, 254801 (2019).
  47. B. Kettle et al., Commun. Phys. 7, 247 (2024).
  48. W. Lu, M. Tzoufras, C. Joshi, F. S. Tsung, W. B. Mori, J. Vieira, R. A. Fonseca, and L. O. Silva, Phys. Rev. ST Accel. Beams 10, 061301 (2007).
  49. P. Foster, M. Streeter, J. Green, F. Cameron, C. Spindloe, G. Schumann, M. Tolley, R. Clarke, J. Collier, D. Neely, E. Divall, D. Neville, P. Rice, R. Bickerton, S. Blake, P. Holligan, P. Brumitt, and P. P. Rajeev, in The European Conference on Lasers and Electro-Optics (Optica Publishing Group, Washington DC, 2009), p. CG_P12.
  50. O. Kononenko, N. Lopes, J. Cole, C. Kamperidis, S. Mangles, Z. Najmudin, J. Osterhoff, K. Poder, D. Rusby, D. Symes, J. Warwick, J. Wood, and C. Palmer, Nucl. Instrum. Methods Phys. Res., Sect. A 829, 125 (2016).
  51. R. Luo, G. R. Christian, M. P. Backhouse, N. C. Lopes, S. S. Alatabi, M. S. Bloom, M. Maier, and Z. Najmudin, High Power Laser Sci. Eng. 13, e95 (2025).
  52. I. Glatt and O. Kafri, Opt. Lasers Eng. 8, 277 (1988).
  53. B. Pollock et al., in Particle Accelerator Conference (PAC 09) (JaCoW, Geneva, Switzerland, 2010), p. WE6RFP101.
  54. K. Põder, J. C. Wood, N. C. Lopes, J. M. Cole, S. Alatabi, M. P. Backhouse, P. S. Foster, A. J. Hughes, C. Kamperidis, O. Kononenko, S. P. D. Mangles, C. A. J. Palmer, D. Rusby, A. Sahai, G. Sarri, D. R. Symes, J. R. Warwick, and Z. Najmudin, Phys. Rev. Lett. 132, 195001 (2024).
  55. K. A. Tanaka, T. Yabuuchi, T. Sato, R. Kodama, Y. Kitagawa, T. Takahashi, T. Ikeda, Y. Honda, and S. Okuda, Rev. Sci. Instrum. 76, 013507 (2004).
  56. K. Zeil, S. D. Kraft, A. Jochmann, F. Kroll, W. Jahr, U. Schramm, L. Karsch, J. Pawelke, B. Hidding, and G. Pretzler, Rev. Sci. Instrum. 81, 013307 (2010).
  57. E. Esarey, B. A. Shadwick, P. Catravas, and W. P. Leemans, Phys. Rev. E 65, 056505 (2002).
  58. S. Fourmaux, S. Corde, K. T. Phuoc, P. M. Leguay, S. Payeur, P. Lassonde, S. Gnedyuk, G. Lebrun, C. Fourment, V. Malka, S. Sebban, A. Rousse, and J. C. Kieffer, New J. Phys. 13, 033017 (2011).
  59. A. G. R. Thomas, Phys. Plasmas 17, 056708 (2010).
  60. See Supplemental Material at http://link.aps.org/supplemental/10.1103/krsl-322s for further information on the x-ray spectral measurements and additional analysis of the simulation.
  61. M. J. V. Streeter, S. Kneip, M. S. Bloom, R. A. Bendoyro, O. Chekhlov, A. E. Dangor, A. Döpp, C. J. Hooker, J. Holloway, J. Jiang, N. C. Lopes, H. Nakamura, P. A. Norreys, C. A. J. Palmer, P. P. Rajeev, J. Schreiber, D. R. Symes, S. P. D. Wing, S. Mangles, and Z. Najmudin, Phys. Rev. Lett. 120, 254801 (2018).
  62. C. D. Decker, W. B. Mori, K. Tzeng, and T. Katsouleas, Phys. Plasmas 3, 2047 (1996).
  63. M. Heigoldt, A. Popp, K. Khrennikov, J. Wenz, S. W. Chou, S. Karsch, S. I. Bajlekov, S. M. Hooker, and B. Schmidt, Phys. Rev. ST Accel. Beams 18, 121302 (2015).
  64. F. Fang, C. E. Clayton, K. A. Marsh, A. E. Pak, J. E. Ralph, N. C. Lopes, and C. Joshi, Plasma Phys. Controlled Fusion 51, 024003 (2009).
  65. S. Kalmykov, S. A. Yi, V. Khudik, and G. Shvets, Phys. Rev. Lett. 103, 135004 (2009).
  66. A. Sävert, S. P. D. Mangles, M. Schnell, E. Siminos, J. M. Cole, M. Leier, M. Reuter, M. B. Schwab, M. Möller, K. Poder, O. Jäckel, G. G. Paulus, C. Spielmann, S. Skupin, Z. Najmudin, and M. C. Kaluza, Phys. Rev. Lett. 115, 055002 (2015).
  67. J. D. Jackson, Classical Electrodynamics (Wiley, New York, 1999), 3rd ed.
  68. A. G. Khachatryan, A. Irman, F. A. van Goor, and K.-J. Boller, Phys. Rev. ST Accel. Beams 10, 121301 (2007).
  69. S. Cipiccia et al., Nat. Phys. 7, 867 (2011).
  70. W. Yan, L. Chen, D. Li, L. Zhang, N. a. M. Hafz, J. Dunn, Y. Ma, K. Huang, L. Su, M. Chen, Z. Sheng, and J. Zhang, Proc. Natl. Acad. Sci. U.S.A. 111, 5825 (2014).
  71. S. Fourmaux, K. Otani, A. Saraf, S. MacLean, M. J. Wesolowski, P. S. Babyn, E. Hallin, A. Krol, and J. C. Kieffer, in Relativistic Plasma Waves and Particle Beams as Coherent and Incoherent Radiation Sources, edited by D. A. Jaroszynski, International Society for Optics and Photonics (SPIE, Bellingham, Washington, USA, 2015), Vol. 9509, p. 950907, 10.1117/12.2087603.
  72. A. Döpp, B. Mahieu, A. Lifschitz, C. Thaury, A. Doche, E. Guillaume, G. Grittani, O. Lundh, M. Hansson, J. Gautier, M. Kozlova, J.-P. Goddet, P. Rousseau, A. Tafzi, V. Malka, A. Rousse, S. Corde, and K. Ta Phuoc, Light Sci. Appl. 6, e17086 (2017).
  73. F. Albert, N. Lemos, J. L. Shaw, B. B. Pollock, C. Goyon, W. Schumaker, A. M. Saunders, K. A. Marsh, A. Pak, J. E. Ralph, J. L. Martins, L. D. Amorim, R. W. Falcone, S. H. Glenzer, J. D. Moody, and C. Joshi, Phys. Rev. Lett. 118, 134801 (2017).
  74. C. F. Dong, T. Z. Zhao, K. Behm, P. G. Cummings, J. Nees, A. Maksimchuk, V. Yanovsky, K. Krushelnick, and A. G. R. Thomas, Phys. Rev. Accel. Beams 21, 041303 (2018).
  75. R. Rakowski, P. Zhang, K. Jensen, B. Kettle, T. Kawamoto, S. Banerjee, C. Fruhling, G. Golovin, D. Haden, M. S. Robinson, D. Umstadter, B. A. Shadwick, and M. Fuchs, Sci. Rep. 12, 10855 (2022).
  76. R. Lehe, M. Kirchen, I. A. Andriyash, B. B. Godfrey, and J.-L. Vay, Comput. Phys. Commun. 203, 66 (2016).
  77. S. Y. Kalmykov, A. Beck, S. A. Yi, V. N. Khudik, M. C. Downer, E. Lefebvre, B. A. Shadwick, and D. P. Umstadter, Phys. Plasmas 18, 056704 (2011).
  78. F. S. Tsung, C. Ren, L. O. Silva, W. B. Mori, and T. Katsouleas, Proc. Natl. Acad. Sci. U.S.A. 99, 29 (2002).
  79. J. Faure, Y. Glinec, J. J. Santos, F. Ewald, J.-P. Rousseau, S. Kiselev, A. Pukhov, T. Hosokai, and V. Malka, Phys. Rev. Lett. 95, 205003 (2005).
  80. J. Götzfried, A. Döpp, M. F. Gilljohann, F. M. Foerster, H. Ding, S. Schindler, G. Schilling, A. Buck, L. Veisz, and S. Karsch, Phys. Rev. X 10, 041015 (2020).
  81. Y. Ma et al., Phys. Rev. X 15, 031062 (2025).
  82. S. Kneip, S. R. Nagel, C. Bellei, N. Bourgeois, A. E. Dangor, A. Gopal, R. Heathcote, S. P. D. Mangles, J. R. Marquès, A. Maksimchuk, P. M. Nilson, K. T. Phuoc, S. Reed, M. Tzoufras, F. S. Tsung, L. Willingale, W. B. Mori, A. Rousse, K. Krushelnick, and Z. Najmudin, Phys. Rev. Lett. 100, 105006 (2008).

Outline

Information

Phys. Rev. Lett. 137, 105001– Published 3 September, 2026
  • Received 13 September 2024
  • Accepted 9 July 2026
Crossmark - Check for updates button
Creative Commons Logo

Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.

Published by the American Physical Society

Sign In to Your Journals Account

Filter

Filter

Article Lookup

Enter a citation