排序方式: 共有47条查询结果,搜索用时 31 毫秒
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Laser-induced microexplosion confined in the bulk of a sapphire crystal: evidence of multimegabar pressures 总被引:1,自引:0,他引:1
Juodkazis S Nishimura K Tanaka S Misawa H Gamaly EG Luther-Davies B Hallo L Nicolai P Tikhonchuk VT 《Physical review letters》2006,96(16):166101
Extremely high pressures (approximately 10 TPa) and temperatures (5 x 10(5) K) have been produced using a single laser pulse (100 nJ, 800 nm, 200 fs) focused inside a sapphire crystal. The laser pulse creates an intensity over 10(14) W/cm2 converting material within the absorbing volume of approximately 0.2 microm3 into plasma in a few fs. A pressure of approximately 10 TPa, far exceeding the strength of any material, is created generating strong shock and rarefaction waves. This results in the formation of a nanovoid surrounded by a shell of shock-affected material inside undamaged crystal. Analysis of the size of the void and the shock-affected zone versus the deposited energy shows that the experimental results can be understood on the basis of conservation laws and be modeled by plasma hydrodynamics. Matter subjected to record heating and cooling rates of 10(18) K/s can, thus, be studied in a well-controlled laboratory environment. 相似文献
42.
A. A. Andreev J. Limpouch J. Psikal K. Yu. Platonov V. T. Tikhonchuk 《The European physical journal. Special topics》2009,175(1):123-126
Laser interactions with mass-limited targets (MLT) are studied via 2D3V relativistic electromagnetic PIC simulations. Analytical
estimates are derived to clarify the simulation results. MLT limit undesirable spread of absorbed laser energy out of the
interaction zone. MLT, such as droplets, are shown here to enhance the achievable fast ion energy significantly. For given
target dimensions, the existence is demonstrated of an optimum laser beam diameter when ion acceleration is efficient and
geometrical energy losses are still acceptable. Ion energy also depends on target geometrical form and shaped targets are
found to be preferable for high ion energy. 相似文献
43.
Roland Duclous Bruno Dubroca Francis Filbet Vladimir Tikhonchuk 《Journal of computational physics》2009,228(14):5072-5100
A high order, deterministic direct numerical method is proposed for the non-relativistic 2Dx×3Dv Vlasov–Maxwell system, coupled with Fokker–Planck–Landau collision operators. The magnetic field is perpendicular to the 2Dx plane surface of computation, whereas the electric fields occur in this plane. Such a system is devoted to modelling of electron transport and energy deposition in the general frame of Inertial Confinement Fusion applications. It is able to describe the kinetics of the plasma electrons in the nonlocal equilibrium regime, and permits to consider a large anisotropy degree of the distribution function. We develop specific methods and approaches for validation, that might be used in other fields where couplings between equations, multiscale physics, and high dimensionality are involved. Fast algorithms are employed, which makes this direct approach computationally affordable for simulations of hundreds of collisional times. 相似文献
44.
The renormalization group approach is applied to derive an exact solution to self-consistent Vlasov kinetic equations for plasma particles in the quasineutral approximation. The solution obtained describes the one-dimensional adiabatic expansion into vacuum of a plasma bunch with arbitrary initial velocity distributions of the electrons and ions. The ion acceleration is investigated for both a Maxwellian two-temperature initial electron distribution and a super-Gaussian initial electron distribution. 相似文献
45.
Depierreux S Labaune C Fuchs J Pesme D Tikhonchuk VT Baldis HA 《Physical review letters》2002,89(4):045001
Thomson scattering has been used to investigate the nonlinear evolution of electron plasma waves (EPWs) generated by stimulated Raman scattering (SRS). Two complementary diagnostics demonstrate the occurrence of the cascade of Langmuir decay instabilities (LDI). The EPW wave-number spectrum displays an asymmetric broadening towards small wave numbers, interpreted as a signature of the secondary EPWs produced in the LDI cascade. The number of cascade steps is in agreement with the broadening of the associated ion-acoustic-waves' spectra. The total energy transferred in the EPWs cascade is found to be either less than or of the same order of magnitude as the energy of the primary EPW. 相似文献
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