https://doi.org/10.1140/epjs/s11734-025-01550-x
Regular Article
Measurement of early hot electrons in low-gas-fill hohlraum on Shenguang-100 kJ laser facility
1
National Key Laboratory of Plasma Physics, Laser Fusion Research Center, China Academy of Engineering Physics, 621900, Mianyang, China
2
Institute of Applied Physics and Computational Mathematics, 100088, Beijing, China
3
School of Physics and Electronics, Hunan University, 410082, Changsha, China
4
Center for Applied Physics and Technology, Peking University, 100871, Beijing, China
Received:
16
August
2024
Accepted:
21
February
2025
Published online:
14
March
2025
Early hot electron can preheat the pellet fuel and thus lead to lower implosion performance. The properties of hot electrons in early stage of implosion experiments in Shenguang-100 kJ laser facility were investigated. It was shown that both the temperature and the energy of early hot electrons were very low. The upper limit of the temperature and the energy of early hot electrons in our experiments were only 7.7 keV and 0.35 J, respectively. Besides, the generation mechanisms of early hot electrons were also different from NIF experiments according to the results of the hard X-ray imager (HXI). In NIF experiments, two-plasmon decay and multi-beam stimulated Raman scattering (SRS) were dominate mechanisms that generate early hot electrons. However, SRS of the outer beams was our dominant mechanism. Spectrum of the scattered light of SRS was obtained by radiative hydrodynamic and ray-tracing simulations. The result showed that the spectrum was peaked at 
, which meant hot electrons with the temperature near 7keV can be generated. And from the result of HXI, hot electrons deposited onto the pellet were estimated to less than 
J. Deeper analysis showed that, in the beam overlapping region, the plasma density was unsuitable for multi-beam SRS, so no hot electrons with larger temperature were generated.
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Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.
