| Autor: |
Yun-Qian Cui, Wei-Min Wang, Zheng-Ming Sheng, Yu-Tong Li, Jie Zhang |
| Předmět: |
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| Zdroj: |
Plasma Physics & Controlled Fusion; 2013, Vol. 55 Issue 8, p1-7, 7p |
| Abstrakt: |
Laser absorption in the interaction between ultra-intense femtosecond laser and solid density plasma is studied integratedly for the intensity range Iλ2 1014-1020 W cm-2 µm² by particle-in-cell simulations with collision modulus included. The collisional effect is found to be significant when the incident laser intensity is less than 1016 W cm-2 µm², which tends to enhance the resonance absorption and reduce the vacuum heating under different plasma parameters. At higher intensities, various collisionless absorption mechanisms dominate with a large number of hot electrons produced. The scaling of hot electron temperatures is found to depend upon the dominant absorption mechanisms. At moderate intensity around 1017 W cm-2, the scaling law is Thot ... (Iλ²)1/3 when the incident angle matches the optimized angle of resonance absorption; otherwise, Thot ... (Iλ²)α with α > 1/3, which changes with laser incident angles and preplasma scale lengths; in the case of vacuum heating, usually α > 1. At laser intensity above 1018 W cm-2 µm² when the absorption mechanism is dominated by ponderomotive acceleration, the scaling becomes Thot ... (Iλ²)1/2. The angular distributions of hot electrons are also shown to be dependent upon the absorption mechanisms. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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