Abstract
Nanowire arrays are excellent nanostructured target materials for high-energy density (HED) science and applications because of their enhanced energy absorption properties. However, investigations of the spatiotemporal dynamics of laser-irradiated nanowire arrays remain limited, since conventional time-resolved diagnostics cannot capture the rapid plasma-state transitions. This study reports spatiotemporally resolved measurements of laser energy absorption and electron transport in laser-irradiated nanowire arrays using an X-ray free-electron laser (XFEL). The XFEL measurements showed that the nanowire array is promptly heated to an electron temperature of ~ 120 eV at the main-pulse interaction peak, followed by a further increase to ~ 140 eV around 10 ps, which was associated with wire collapse. The experimental results also confirmed that further enlargement of the heated area was suppressed by the restricted electron transport in nanowire arrays. These observations advance our understanding of HED plasma formation and evolution within the laser-irradiated nanowire arrays, laying a foundation for various applications.
Data availability
The data that support the findings of this study are available from the corresponding author upon reasonable request.
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Acknowledgements
The XFEL experiments were performed at BL2 of SACLA with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal No. 2024B8051, 2024A8013, 2023A8015, 2023A8018, and 2021B8070). The authors would like to acknowledge the dedicated technical support provided by the staff at SACLA for XFEL operation and X-ray diagnostics. Authors would like to acknowledge Editage for English language editing.
Funding
The XFEL experiments were performed at BL2 of SACLA with the approval of the Japan Synchrotron Radiation Research Institute (JASRI) (Proposal No. 2024B8051, 2024A8013, 2023A8015, 2023A8018, and 2021B8070). This work was performed under the Institute of Laser Engineering (ILE) joint research project at The University of Osaka (Contract subjects 2025B2-016SAWADA, 2024B2-019SAWADA, and 2023B2-018SAWADA). D. T. received support from the Japan Society for the Promotion of Science (KAKENHI Grant No. 23KJ1526). D. T. also received support from the SACLA Research Support Program for Graduate Students. H. S. was supported by the National Science Foundation under Grant No. 2010502 through the NSF/DOE Partnership in Basic Plasma Science and Engineering. C. N. was partially supported by JST SPRING (Grant number JPMJSP2138).
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D. T. wrote the original manuscript after receiving input and feedback from H. S., C. N., Y. T., T. Y., Y. S., N. O., K. Y., and K. Shigemori. D. T. led the formal analysis and visualization with support from H. S., D. T., H. S., C. N., S. M., T. S., I. N., S. H., T. Y., K. M., K. Sueda, and K. Shigemori performed the experiments and acquired data. T. Y., K. M., Y. I., and K. Sueda operated the high-power femtosecond laser system. Y. S. conducted PIC simulation. D. T. prepared the nanowire array samples with the support of T. Somekawa, T. Shimizu, S. S., and K. Y. K. Shigemori, who proposed and organized this study.
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Tanaka, D., Sawada, H., Nakatsuji, C. et al. Ultrafast plasma dynamics in laser-irradiated nanowire arrays probed with an X-ray free-electron laser. Sci Rep (2026). https://doi.org/10.1038/s41598-026-47126-0
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DOI: https://doi.org/10.1038/s41598-026-47126-0
