In depth fusion flame spreading with a deuterium—tritium plane fuel density profile for plasma block ignition

Abstract

Solid-state fuel ignition was given by Chu and Bobin according to the hydrodynamic theory at x = 0 qualitatively. A high threshold energy flux density, i.e., E* = 4.3 × 1012 J/m2, has been reached. Recently, fast ignition by employing clean petawatt—picosecond laser pulses was performed. The anomalous phenomena were observed to be based on suppression of prepulses. The accelerated plasma block was used to ignite deuterium—tritium fuel at solid-state density. The detailed analysis of the thermonuclear wave propagation was investigated. Also the fusion conditions at x ≠ 0 layers were clarified by exactly solving hydrodynamic equations for plasma block ignition. In this paper, the applied physical mechanisms are determined for nonlinear force laser driven plasma blocks, thermonuclear reaction, heat transfer, electron—ion equilibration, stopping power of alpha particles, bremsstrahlung, expansion, density dependence, and fluid dynamics. New ignition conditions may be obtained by using temperature equations, including the density profile that is obtained by the continuity equation and expansion velocity. The density is only a function of x and independent of time. The ignition energy flux density, E*t, for the x ≠ 0 layers is 1.95 × 1012 J/m2. Thus threshold ignition energy in comparison with that at x = 0 layers would be reduced to less than 50 percent.

The internal propagation of fusion flame with the strong shock of a laser driven plasma block for advanced nuclear fuel ignition

“…( 4), ( 5), ( 13), ( 16), ( 18) and ( 19) of Ref. [5]) at r = 0 layers are written by changing x to r as follows:…”

“…The expansion and conduction appear in the hydrodynamic equations for plasma block ignition. [5] The shock ignition wave is generated by the assembled fuel ignition from a central hot spot when the massive cryogenic shells are first imploded by direct lasers. [6] The external factors are easily controlled by laser pulses, size selection, and fuel type.…”

“…The in-depth plasma block ignition is a new method for the ignition of solid advanced fuels. [5] Due to the low cross section, the ignition of the advanced fuels would be difficult with the plasma block method, [10][11][12] and controlled complementary mechanisms are needed. Therefore, the fusion conditions are met by the compression of the fuel by another laser with a longer duration pulse and the generated shock wave by impacting the plasma block with the solid fuel.…”

“…In this paper, the radial fusion flame propagation at r = 0 layers [5] is studied including the generated shock wave by impacting the plasma block with the solid fuel for the advanced fuels, and the fusion conditions of non-radioactive fuels are investigated theoretically. The threshold ignition energy is characterized, and the slower thermalization for ion heating is shown.…”

Effects of density profile and multi-species target on laser-heated thermal-pressure-driven shock wave acceleration

“…High-energy proton or ion beams are very important for many significant applications, such as fast ignition fusion, cancer therapy, hadron colliders, etc. [1][2][3] Conventional accelerators usually require extraordinary occupying area and abundant cost because of the low accelerating gradient. These restrict their applications and popularizations.…”