Ultrafast ignition with relativistic shock waves induced by high power lasers

Abstract

In this paper we consider laser intensities greater than 10 16 W cm −2 where the ablation pressure is negligible in comparison with the radiation pressure. The radiation pressure is caused by the ponderomotive force acting mainly on the electrons that are separated from the ions to create a double layer (DL). This DL is accelerated into the target, like a piston that pushes the matter in such a way that a shock wave is created. Here we discuss two novel ideas. Firstly, the transition domain between the relativistic and non-relativistic laser-induced shock waves. Our solution is based on relativistic hydrodynamics also for the above transition domain. The relativistic shock wave parameters, such as compression, pressure, shock wave and particle flow velocities, sound velocity and rarefaction wave velocity in the compressed target, and temperature are calculated. Secondly, we would like to use this transition domain for shockwave-induced ultrafast ignition of a pre-compressed target. The laser parameters for these purposes are calculated and the main advantages of this scheme are described. If this scheme is successful a new source of energy in large quantities may become feasible.

Laser-induced fusion detonation wave

“…It is important to emphasize that if we take P 0 = 0, then we get only the κ > 4 solutions (Eliezer et al, 2014a); therefore, in order to see the behavior at the transition between relativistic and nonrelativistic domains one has to take P 0 ≠ 0! In this case, we get from Eqs.…”

“…We suggested recently a novel shock wave ignition scheme (Eliezer et al, 2014a;Eliezer et al, 2015), where the ignition shock wave is generated in a pre-compressed target by the ponderomotive force (Hora, 1991;Eliezer, 2002) of a high-irradiance laser pulse. The shock wave velocity in this scheme is in the intermediate domain between the relativistic (Taub, 1948;Landau & Lifshitz, 1987) and non-relativistic (Zeldovich & Raizer, 1966;Fortov & Lomonosov, 2010) hydrodynamics.…”

Physics and applications with laser-induced relativistic shock waves

“…The four equations relating the shock wave variables are the three Hugoniot relations describing the conservation laws of energy, momentum and particles and the EOS connecting the thermodynamic variables of the state under consideration [3–5] . The fifth equation necessary to solve the problem is obtained in a model [26] where the pressure is induced by the laser ponderomotive force and its strength is a function of the laser pulse parameters [27] .…”

“…The relativistic shock wave of Equations (5) with , where and are much smaller than , the velocities satisfy , yield the following non-relativistic well-known Hugoniot equations, For the relativistic case we have to solve Equations (5) together with the piston model equation [21, 27] Equations (5) and (7) are five equations with five unknowns: , , , , assuming that we know , , , and . The calculations are conveniently done in the dimensionless units defined by Substituting the ideal gas EOS into the third of Equations (5) we get the relativistic Hugoniot equation It is important to emphasize that if we take then we get only the solutions.…”

A novel solution to the Klein–Gordon equation in the presence of a strong rotating electric field

“…One can verify that substituting the Floquet ansatz (9) into (18) yields the recursion relation (10) with µ = − √ λ and V 2n identical to (17). It implies that as long as (16) holds, the original 2 nd order equation is equivalent to an effective 1 st order one. The effective equation (18) admits the straightforward solution…”