| 研究課題/領域番号 |
19H00669
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| 研究機関 | 国立研究開発法人量子科学技術研究開発機構 |
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研究代表者 |
PIROZHKOV Alex 国立研究開発法人量子科学技術研究開発機構, 関西光科学研究所 光量子科学研究部, 上席研究員 (00446410)
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| 研究分担者 |
Esirkepov Timur 国立研究開発法人量子科学技術研究開発機構, 関西光科学研究所 光量子科学研究部, 上席研究員 (10370363)
匂坂 明人 国立研究開発法人量子科学技術研究開発機構, 関西光科学研究所 光量子科学研究部, 主幹研究員 (20354970)
小倉 浩一 国立研究開発法人量子科学技術研究開発機構, 関西光科学研究所 光量子科学研究部, 専門業務員 (30354971)
Pikuz Tatiana 大阪大学, 先導的学際研究機構, 特任准教授(常勤) (20619978)
難波 愼一 広島大学, 先進理工系科学研究科(工), 教授 (00343294)
桐山 博光 国立研究開発法人量子科学技術研究開発機構, 関西光科学研究所 光量子科学研究部, グループリーダー (40354972)
Koga James 国立研究開発法人量子科学技術研究開発機構, 関西光科学研究所 光量子科学研究部, 専門業務員 (70370393)
神門 正城 国立研究開発法人量子科学技術研究開発機構, 関西光科学研究所 光量子科学研究部, 次長 (50343942)
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| 研究期間 (年度) |
2019-04-01 – 2024-03-31
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| キーワード | Coherent x-ray source / New imaging paradigm / BISER / Relativistic plasma / Plasma singularities |
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| 研究実績の概要 |
We performed a joint international experiment with the J-KAREN-P laser in KPSI QST, Japan, with participation of overseas researchers from ELI-Beamlines (Czech Republic) and National Taiwan University (Taiwan). We measured near-axis angular distribution of the BISER coherent x-ray source, which resulted in >5° beam. Together with the 2021 Astra experiment data, this means the total coherent x-ray yield of ~100 μJ in the 17-34 nm region, which is a significant achievement.
We improved the Magnetic Bottle Electron Spectrometer (MBES) signal by ~2 orders of magnitude, which is a big step towards the attosecond pulse measurement. We obtained bright coherent diffraction patterns of 3-period nano-scale object (transmission grating with the main period of 200 nm), which is a big step towards the attosecond lensless imaging.
We published 2 refereed papers: one on the Project's core diagnostics, x-ray spectroscopy and instruments [Rev.Sci.Instr. 2023] and one on the design of experiment on black hole studies with strongly accelerating relativistic mirror, which is also a singularity-based coherent x-ray source [Photonics 2022].
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| 現在までの達成度 (区分) |
現在までの達成度 (区分)
2: おおむね順調に進展している
理由
In 2021 we measured a very bright BISER using a narrow-acceptance-angle on-axis spectrograph. To estimate the full (wide-angle) BISER beam energy, in 2022 we assembled a special setup with an on-axis 3" normal-incidence multilayer mirror directing a defocused beam onto an x-ray CCD. A mesh in front of the mirror provided absolute angular calibration. To avoid filter damage by multi-terawatt laser, we performed tests before the main experiment and adjusted the parameters accordingly. Finally, we measured the near-axis BISER angular distribution: the entire BISER beam was larger than 5°. This corresponds to ~100 μJ full beam energy and ~10^13 photons in the 17-34 nm region, which is similar to XUV FELs.
We tested a soft-edge mask to control the laser near-field which allowed to use higher laser power and obtain brighter BISER.
We started the coherent x-ray imaging experiments: we irradiated plastic microspheres in the shadow mode and a 3-period transmission grating (200 nm, 4 μm, and 150 μm) in the diffraction mode. The diffractive image was bright, and its 1st diffraction order was saturated.
In 2020 we started to operate the MBES (Magnetic Bottle Electron Spectrometer), but the signal was not strong and had a low S/N ratio. In 2022 we improved the MBES x-ray beamline, increasing the MBES signal by 2 orders of magnitude, resulting in high S/N ratio ToF spectra of Auger and photoelectrons from Xe 4d and 5p inner shells.
We started to use various 3D-printed parts in the experiment which allowed more flexible and quickly changing setups.
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| 今後の研究の推進方策 |
We plan to perform a joint international BISER experiment with the J-KAREN-P laser. We will further improve the setup and diagnostics to enhance the BISER coherent x-ray source brightness and better understand its physics. The J-KAREN-P laser will be upgraded by installing an additional deformable mirror to improve the focal spot quality and using a more advanced Intrepid laser for pumping the OPCPA stage to improve stability and contrast.
We will improve the x-ray imaging setup, namely, improve the light shield to reduce the stray light (background), and introduce additional motorized stages for greater flexibility.
Based on the previous two years of experience we will further improve the Magnetic Bottle Electron Spectrometer (MBES) to significantly increase its resolution and S/N ratio.
We plan to further shorten the optical probe pulse duration, and introduce a femtosecond gating to the Top View image, to achieve higher time resolution in diagnostics of relativistic singularities. These techniques were prepared in our companion Kakenhi Project 国際共同研究加速基金(国際共同研究強化(A)) 19KK0355.
We will continue PIC and nozzle gas dynamic simulations for experiment analysis and guiding.
We will publish our results in high-impact journals.
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