- Physical Review Journals
All JournalsPhysics Magazine

Physical Review Research

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

Competition between one- and two-photon processes in Ar irradiated by the Shanghai soft x-ray free electron laser

Ruichao Dong1,2,7,*, Jie Yan3,4,*, Jinze Feng2, Mingjie Zhang1,7, Yikang Zhang2, Yuliang Guo2, Ahai Chen2, Zhenjie Shen2, Yuneng Shen2 et al.

Zhen Wang1, Kaiqing Zhang1, Xuan Li1, Zheng Qi1, Zhangfeng Gao1, Zenggong Jiang1, Jiaming Jiang2, Bin Li1, Chao Feng1, Bo Liu1, Huaidong Jiang2, Zhi Liu2, Yajiang Hao5, Kiyoshi Ueda2,8, Cheng Gao4,†, Xincheng Wang2,‡, and Yuhai Jiang2,6,1,§

  • *These authors contributed equally to this work.
  • †Contact author: gaocheng@nudt.edu.cn
  • ‡Contact author: wangxch1@shanghaitech.edu.cn
  • §Contact author: jiangyh3@shanghaitech.edu.cn
PDF

Phys. Rev. Research 7, 033174 – Published 21 August, 2025

DOI: https://doi.org/10.1103/j4rx-55m2

Abstract

Shanghai Soft X-ray Free Electron Laser facility has entered user operation, delivering soft x-ray pulses in self-amplified spontaneous emission mode with an intensity of the peak fluence of ∼1.0×10−2µJ/µm2 at a focus point. With these conditions, at a photon energy of 260 eV, we expect sequential processes in which Ar2+ created by the Auger decay following the 2p photoionization may be resonantly excited to the 2p−13p−23d inner-shell excited state and thus resonant Auger decay produces Ar3+, which can also be competitively produced by the direct double Auger decay (DDAD) following the one-photon 2p ionization of Ar. Ar4+ ions dominantly arise from Ar2+ with a resonant excitation and subsequent DDAD, involving two-photon absorption. The measured charge distributions as a function of the free-electron laser (FEL) fluence are well reproduced by ab initio calculations that include DDAD, normally neglected in the previous FEL studies, and resonant Auger decay. The present results demonstrate that the low peak fluence of the FEL pulses can be determined if the competition between the one- and two-photon processes is precisely described along with DDAD and resonant Auger decay.

View figure in article

Physics Subject Headings (PhySH)

Article Text

Supplemental Material

References (50)

  1. B. Liu, C. Feng, D. Gu, F. Gao, H. Deng, M. Zhang, S. Sun, S. Chen, W. Zhang, W. Fang, Z. Wang, Q. Zhou, Y. Leng, M. Gu, L. Yin, Q. Gu, G. Fang, D. Wang, and Z. Zhao, The SXFEL upgrade: From test facility to user facility, Appl. Sci. (Basel) 12, 176 (2022).
  2. Y. H. Jiang, A. Rudenko, O. Herrwerth, L. Foucar, M. Kurka, K. U. Kühnel, M. Lezius, M. F. Kling, J. van Tilborg, A. Belkacem, K. Ueda, S. Düsterer, R. Treusch, C. D. Schröter, R. Moshammer, and J. Ullrich, Ultrafast extreme ultraviolet induced isomerization of acetylene cations, Phys. Rev. Lett. 105, 263002 (2010).
  3. J. Ullrich, A. Rudenko, and R. Moshammer, Free-electron lasers: New avenues in molecular physics and photochemistry, Annu. Rev. Phys. Chem. 63, 635 (2012).
  4. K. Nagaya et al., Ultrafast dynamics of a nucleobase analogue illuminated by a short intense x-ray free electron laser pulse, Phys. Rev. X 6, 021035 (2016).
  5. L. Young et al., Roadmap of ultrafast x-ray atomic and molecular physics, J. Phys. B: At. Mol. Opt. Phys. 51, 032003 (2018).
  6. C. Callegari, A. Grum-Grzhimailo, K. Ishikawa, K. Prince, G. Sansone, and K. Ueda, Atomic, molecular and optical physics applications of longitudinally coherent and narrow bandwidth free-electron lasers, Phys. Rep. 904, 1 (2021).
  7. L. Young, E. Kanter, B. Krässig, Y. Li, A. March, T. Pratt, R. Santra, S. Southworth, N. Rohringer, L. Dimauro, G. Doumy, C. Roedig, N. Berrah, L. Fang, M. Hoener, P. Bucksbaum, J. Cryan, S. Ghimire, J. Glownia, and M. Messerschmidt, Femtosecond electronic response of atoms to ultra-intense x-rays, Nature (London) 466, 56 (2010).
  8. P. J. Ho, C. Bostedt, S. Schorb, and L. Young, Theoretical tracking of resonance-enhanced multiple ionization pathways in x-ray free-electron laser pulses, Phys. Rev. Lett. 113, 253001 (2014).
  9. R. Moshammer et al., Few-photon multiple ionization of Ne and Ar by strong free-electron-laser pulses, Phys. Rev. Lett. 98, 203001 (2007).
  10. A. Rudenko et al., Recoil-ion momentum distributions for two-photon double ionization of He and Ne by 44 eV free-electron laser radiation, Phys. Rev. Lett. 101, 073003 (2008).
  11. Y. Hikosaka, M. Fushitani, A. Matsuda, C.-M. Tseng, A. Hishikawa, E. Shigemasa, M. Nagasono, K. Tono, T. Togashi, H. Ohashi, H. Kimura, Y. Senba, M. Yabashi, and T. Ishikawa, Multiphoton double ionization of Ar in intense extreme ultraviolet laser fields studied by shot-by-shot photoelectron spectroscopy, Phys. Rev. Lett. 105, 133001 (2010).
  12. E. P. Kanter et al., Unveiling and driving hidden resonances with high-fluence, high-intensity x-ray pulses, Phys. Rev. Lett. 107, 233001 (2011).
  13. A. Rörig, S.-K. Son, T. Mazza, P. Schmidt, T. M. Baumann, B. Erk, M. Ilchen, J. Laksman, V. Music, S. Pathak, D. E. Rivas, D. Rolles, S. Serkez, S. Usenko, R. Santra, M. Meyer, and R. Boll, Multiple-core-hole resonance spectroscopy with ultraintense x-ray pulses, Nat. Commun. 14, 5738 (2023).
  14. W. Xiang, G. Cheng, Y. Fu, J. Zeng, and J. Yuan, Inner-shell resonant absorption effects on evolution dynamics of the charge state distribution in a neon atom interacting with ultraintense x-ray pulses, Phys. Rev. A 86, 061401 (2012).
  15. B. Rudek, S.-K. Son, L. Foucar, S. Epp, B. Erk, R. Hartmann, M. Adolph, R. Andritschke, A. Aquila, N. Berrah, C. Bostedt, J. Bozek, N. Coppola, F. Filsinger, H. Gorke, T. Gorkhover, H. Graafsma, L. Gumprecht, A. Hartmann, and D. Rolles, Ultra-efficient ionization of heavy atoms by intense x-ray free-electron laser pulses, Nat. Photon. 6, 858 (2012).
  16. B. Rudek et al., Relativistic and resonant effects in the ionization of heavy atoms by ultra-intense hard x-rays, Nat. Commun. 9, 4200 (2018).
  17. S. Schippers, R. Beerwerth, L. Abrok, S. Bari, T. Buhr, M. Martins, S. Ricz, J. Viefhaus, S. Fritzsche, and A. Müller, Prominent role of multielectron processes in K-shell double and triple photodetachment of oxygen anions, Phys. Rev. A 94, 041401 (2016).
  18. R. Beerwerth and S. Fritzsche, MCDF calculations of Auger cascade processes, Eur. Phys. J. D 71, 253 (2017).
  19. R. Beerwerth, T. Buhr, A. Perry-Sassmannshausen, S. O. Stock, S. Bari, K. Holste, A. L. D. Kilcoyne, S. Reinwardt, S. Ricz, D. W. Savin, K. Schubert, M. Martins, A. Müller, S. Fritzsche, and S. Schippers, Near L-edge single and multiple photoionization of triply charged iron ions, Astrophys. J. 887, 189 (2019).
  20. A. Müller, M. Martins, A. Borovik, T. Buhr, A. Perry-Sassmannshausen, S. Reinwardt, F. Trinter, S. Schippers, S. Fritzsche, and A. S. Kheifets, Role of L-shell single and double core-hole production and decay in m-fold (1≤m≤6) photoionization of the Ar+ ion, Phys. Rev. A 104, 033105 (2021).
  21. M. O. Krause, M. L. Vestal, W. H. Johnston, and T. A. Carlson, Readjustment of the neon atom ionized in the K shell by x-rays, Phys. Rev. 133, A385 (1964).
  22. P. Zhang, J. Trester, K. Ueda, M. Han, T. Balčiūnas, and H. J. Wörner, Time-resolved multielectron coincidence spectroscopy of double Auger-Meitner decay following Xe 4d ionization, Phys. Rev. Lett. 132, 083201 (2024).
  23. Y. Hikosaka, T. Kaneyasu, P. Lablanquie, F. Penent, E. Shigemasa, and K. Ito, Multiple Auger decay of the neon 1s-core-hole state studied by multielectron coincidence spectroscopy, Phys. Rev. A 92, 033413 (2015).
  24. J. Viefhaus, S. Cvejanović, B. Langer, T. Lischke, G. Prümper, D. Rolles, A. V. Golovin, A. N. Grum-Grzhimailo, N. M. Kabachnik, and U. Becker, Energy and angular distributions of electrons emitted by direct double Auger decay, Phys. Rev. Lett. 92, 083001 (2004).
  25. C. Buth, R. Beerwerth, R. Obaid, N. Berrah, L. S. Cederbaum, and S. Fritzsche, Neon in ultrashort and intense x-rays from free electron lasers, J. Phys. B: At. Mol. Opt. Phys. 51, 055602 (2018).
  26. K. Tiedtke, J. Feldhaus, U. Hahn, U. Jastrow, T. Nunez, T. Tschentscher, S. V. Bobashev, A. A. Sorokin, J. B. Hastings, S. Moeller, L. Cibik, A. Gottwald, A. Hoehl, U. Kroth, M. Krumrey, H. Schoeppe, G. Ulm, and M. Richter, Gas detectors for x-ray lasers, J. Appl. Phys. 103, 094511 (2008).
  27. T. Maltezopoulos, F. Brinker, F. Dietrich, W. Freund, J. Grünert, U. F. Jastrow, N. Kujala, J. Laksman, J. Liu, K. Tiedtke, and T. Tschentscher, Hard x-ray operation of x-ray gas monitors at the European XFEL, J. Synchrotron Radiat. 31, 681 (2024).
  28. P. Juranić, A. Alarcon, and R. Ischebeck, Online absolute calibration of fast FEL pulse energy measurements, J. Synchrotron Radiat. 30, 500 (2023).
  29. H. Fukuzawa et al., Deep inner-shell multiphoton ionization by intense x-ray free-electron laser pulses, Phys. Rev. Lett. 110, 173005 (2013).
  30. Y. Kumagai et al., Radiation-induced chemical dynamics in Ar clusters exposed to strong x-ray pulses, Phys. Rev. Lett. 120, 223201 (2018).
  31. K. Toyota, Z. Jurek, S.-K. Son, H. Fukuzawa, K. Ueda, N. Berrah, B. Rudek, D. Rolles, A. Rudenko, and R. Santra, xcalib: A focal spot calibrator for intense x-ray free-electron laser pulses based on the charge state distributions of light atoms, J. Synchrotron Radiat. 26, 1017 (2019).
  32. W. Jiang, X. Wang, S. Zhang, R. Dong, Y. Guo, J. Feng, Z. Shen, Z. Zhu, and Y. Jiang, A reaction microscope for AMO science at Shanghai Soft X-ray Free-Electron Laser Facility, Appl. Sci. 12, 1821 (2022).
  33. W. Jiang, X. Wang, S. Zhang, R. Dong, Y. Guo, J. Feng, Z. Shen, T. Yan, Z. Zhu, and Y. Jiang, Dissociative multi-ionization of N2O molecules in strong femtosecond laser field, J. Chem. Phys. 157, 084302 (2022).
  34. R. Dong, A. Chen, J. Feng, S. Zhang, W. Jiang, X. Hu, Y. Wu, J. Wang, X. Wang, and Y. Jiang, Isomerization in highly excited states of triply charged carbon dioxide ions produced by intense laser fields, Phys. Rev. A 110, 053110 (2024).
  35. P. Lablanquie, L. Andric, J. Palaudoux, U. Becker, M. Braune, J. Viefhaus, J. Eland, and F. Penent, Multielectron spectroscopy: Auger decays of the argon 2p hole, J. Electron Spectrosc. Relat. Phenom. 156–158, 51 (2007).
  36. P. Lablanquie, M. Khalal, L. Andric, J. Palaudoux, F. Penent, J.-M. Bizau, D. Cubaynes, K. Jänkälä, Y. Hikosaka, K. Ito, K. Bucar, and M. Žitnik, Multi-electron coincidence spectroscopy: Triple Auger decay of Ar 2p and 2s holes, J. Electron Spectrosc. Relat. Phenom. 220, 125 (2017).
  37. N. Rohringer and R. Santra, X-ray nonlinear optical processes using a self-amplified spontaneous emission free-electron laser, Phys. Rev. A 76, 033416 (2007).
  38. S.-K. Son, L. Young, and R. Santra, Impact of hollow-atom formation on coherent x-ray scattering at high intensity, Phys. Rev. A 83, 033402 (2011).
  39. C. Gao, J. Zeng, Y. Li, F. Jin, and J. Yuan, Versatile code DLAYZ for investigating population kinetics and radiative properties of plasmas in non-local thermodynamic equilibrium, High Energy Density Phys. 9, 583 (2013).
  40. J. Zeng, P. Liu, W. Xiang, and J. Yuan, Level-to-level and total probability for Auger decay including direct double processes of Ar 2p−1 hole states, Phys. Rev. A 87, 033419 (2013).
  41. P. Liu, J. Zeng, and J. Yuan, A practical theoretical formalism for atomic multielectron processes: Direct multiple ionization by a single Auger decay or by impact of a single electron or photon, J. Phys. B: At. Mol. Opt. Phys. 51, 075202 (2018).
  42. L. Liu, Y. Li, C. Gao, and J. Zeng, Dominance of double processes in complete Auger decay of Rb+(3d−1), Phys. Rev. A 101, 012507 (2020).
  43. Y. Li, C. Gao, J. Zeng, and J. Yuan, Effects of single-photon double photoionization and direct double Auger decay on K-shell ionization kinetics of Ar atoms interacting with XFEL pulses, J. Phys. B: At. Mol. Opt. Phys. 55, 025002 (2022).
  44. See Supplemental Material at http://link.aps.org/supplemental/10.1103/j4rx-55m2 for theoretical results for ionization potentials and photoionization cross sections etc.
  45. M. Gu, The flexible atomic code, Can. J. Phys. 86, 675 (2008).
  46. N. Saito and I. Suzuki, Multiple photoionization in Ne, Ar, Kr and Xe from 44 to 1300 eV, Int. J. Mass Spectrom. Ion Processes 115, 157 (1992).
  47. S. Brünken, C. Gerth, B. Kanngießer, T. Luhmann, M. Richter, and P. Zimmermann, Decay of the Ar2s−1 and 2p−1 and Kr3p−1 and 3d−1 hole states studied by photoelectron-ion coincidence spectroscopy, Phys. Rev. A 65, 042708 (2002).
  48. A. Müller, A. Borovik, T. Buhr, J. Hellhund, K. Holste, A. L. D. Kilcoyne, S. Klumpp, M. Martins, S. Ricz, J. Viefhaus, and S. Schippers, Observation of a four-electron Auger process in near-K-edge photoionization of singly charged carbon ions, Phys. Rev. Lett. 114, 013002 (2015).
  49. S.-K. Son and R. Santra, Monte Carlo calculation of ion, electron, and photon spectra of xenon atoms in x-ray free-electron laser pulses, Phys. Rev. A 85, 063415 (2012).
  50. J. Yan, G. Yan, F. Jin, Y. Li, C. Gao, J. Zeng, and J. Yuan, Evolution of level population in Ar interacting with XFEL pulses: Impact of resonant absorptions, J. Phys. B: At. Mol. Opt. Phys. 57, 155601 (2024).

Outline

Information

Phys. Rev. Research 7, 033174– Published 21 August, 2025
  • Received 25 February 2025
  • Accepted 29 July 2025
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