2017 Fiscal Year Research-status Report
Relativistic Flying Mirror Gamma Ray Source
| Project/Area Number |
16K05639
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| Research Institution | National Institutes for Quantum and Radiological Science and Technology |
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Principal Investigator |
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, 上席研究員(定常) (70370393)
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| Co-Investigator(Kenkyū-buntansha) |
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(定常) (10370363)
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| Project Period (FY) |
2016-04-01 – 2019-03-31
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| Keywords | plasma mirror / relativistic |
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| Outline of Annual Research Achievements |
Up to now only weakly relativistic laser pulses have been considered in their reflection off of relativistic mirrors (breaking plasma waves) generated by another high intensity laser pulse propagating in the opposite direction. We have shown by high resolution one dimensional simulations that even nearly relativistic intensity laser pulses can be reflected off the relativistic mirrors. The relativistic upshift, which depends on the phase velocity of the nonlinear plasma wave, was found to agree with analytical estimates predicted by Schroeder et al. [Phys. Rev. Lett. 107, 145002 (2011)]. In the interaction the nearly relativistic intensity laser pulse is relativistically upshifted and produces relativistically upshifted harmonics. In the best case considered in the simulations relativistically upshifted harmonics with wavelengths below 20 nm were generated from the original 3 micron laser pulse. This is approximately 160 times shorter than the original laser wavelength. When the intensity of the laser pulse became too strong, the reflected spectra did not show clear peaks. A paper was written and submitted.
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| Current Status of Research Progress |
Current Status of Research Progress
2: Research has progressed on the whole more than it was originally planned.
Reason
We have found that sufficient resolution for harmonic generation is possible on large supercomputer simulations in 2 dimensions for a thin plasma layer. Since we have discovered that relativistic harmonic generation from the high intensity pulse interaction with the relativistic mirror occurs, we have decided to concentrate on this for the project instead of the gamma ray production as in the original plan, since such a source would be invaluable for short wavelength coherent radiation. In particular we are concentrating on the possibility for photon-photon scattering using focusing mirrors. We have also started to perform 1 dimensional simulations in the ultra-high intensity regime where radiation reaction dominates and gamma ray emission is expected.
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| Strategy for Future Research Activity |
We will continue 2 dimensional simulations to determine the extent of the focusing of the relativistically upshifted harmonics and investigate the possibility for photon-photon scattering. We will perform 3 dimensional simulations within resolution limits and continue to investigate the radiation reaction dominant regime.
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| Causes of Carryover |
The funds were sufficient for the computer resources and travel expenses that we needed. We plan to use the carryover funds for computer resources, travel fees, and possible publication fees.
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