تقرير
Collimated gamma-ray beams from structured laser-irradiated targets -- how to increase the efficiency without increasing the laser intensity
| العنوان: | Collimated gamma-ray beams from structured laser-irradiated targets -- how to increase the efficiency without increasing the laser intensity |
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| المؤلفون: | Jansen, O., Wang, T., Gong, Z., Ribeyre, X., d'Humières, E., Stutman, D., Toncian, T., Arefiev, A. |
| المصدر: | Phys. Rev. Applied 13, 054024 (2020) |
| سنة النشر: | 2019 |
| المجموعة: | Physics (Other) |
| مصطلحات موضوعية: | Physics - Plasma Physics, Physics - Accelerator Physics, Physics - Applied Physics |
| الوصف: | Using three-dimensional kinetic simulations, we examine the emission of collimated gamma-ray beams from structured laser-irradiated targets with a pre-filled cylindrical channel. The channel guides the incident laser pulse, enabling generation of a slowly evolving azimuthal plasma magnetic field that serves two key functions: to enhance laser-driven electron acceleration and to induce emission of gamma-rays by the energetic electrons. Our main finding is that the conversion efficiency of the laser energy into a beam of gamma-rays ($5^{\circ}$ opening angle) can be significantly increased without increasing the laser intensity by utilizing channels with an optimal density. The conversion efficiency into multi-MeV photons increases roughly linearly with the incident laser power $P$, as we increase $P$ from 1 PW to 4 PW while keeping the laser peak intensity fixed at $5 \times 10^{22}$ W/cm$^2$. This scaling is achieved by using an optimal range of plasma densities in the channel between 10 and $20 n_{cr}$, where $n_{cr}$ is the classical cutoff density for electromagnetic waves. The corresponding number of photons scales as $P^2$. One application that directly benefits from such a strong scaling is the pair production via two-photon collisions, with the number of generated pairs increasing as $P^4$ at fixed laser intensity. Comment: 15 pages, 14 figures |
| نوع الوثيقة: | Working Paper |
| DOI: | 10.1103/PhysRevApplied.13.054024 |
| URL الوصول: | http://arxiv.org/abs/1908.06467 |
| رقم الأكسشن: | edsarx.1908.06467 |
| قاعدة البيانات: | arXiv |
| DOI: | 10.1103/PhysRevApplied.13.054024 |
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