Ignition with the help of a shock wave is performed by the interaction of accelerated plasma block by a petawatt-picosecond (PW-ps) laser, with a solid-state density fuel that it is a new possibility for achieving controlled fusion by inertial confinement. The unexpected production of plasma blocks provides new access to the ignition of solid-state density fuel according to the Chu hydrodynamic model. When the produced plasma block by the PW-ps laser hits the main fuel due to the density differences between the plasma block and the main fuel of the shock wave, this progressive wave increases the density of solidified fuels and reduces the energy of the ignition threshold and increases the flammability. In this study, a new discovery of shock waves has been observed leading to the resonance phenomenon. Nuclear heat shock waves resonance in the side-on ignition of fuel in the internal layer of fuel at x ≠ 0 appears from the exact solution of the hydrodynamic equations with respect to the density profile. This important finding achieves the required ignition temperature for solid-state fuel deuterium–tritium (D–T) in certain energies, with a significant increase due to the resonance of thermonuclear waves. This discovery will facilitate practical experiments on the ignition of advanced solid-state fuels with the accelerated plasma blocks by a PW-ps laser at certain energies.

Various liquid and gaseous alternative fuels have been proposed to replace the kerosene as aircraft fuel. Furthermore, new combustion technologies were developed to reduce the emissions of aero-engine. A staged fuel injection arrangement for a lean burn combustion system was applied to improve the operability of an aero-engine by achieving high flame stability at reduced combustion emissions. Originally, both circuits (pilot and main) are fuelled by kerosene; moreover, the pilot injector is operating at low power (engine idle and approach) and the pilot flame is anchored in an airflow recirculation zone. In the case of the performed research, the pilot injector was modified to allow the use of gaseous fuels. Thus, the burner model allows a flexible balancing of the mass flows for gaseous and liquid fuel. The present paper describes the investigation of ignitability for the proposed staged combustor model fuelled by gaseous and liquid fuels. A short overview on physical properties of used fuels is given. To investigate atomisation and ignition, different measurements systems were used. The effectiveness of two ignitor types (spark plug and laser ignitor) was analysed. The ignition performance of the combustor operating on various fuels was compared and discussed in detail.

Recent heavy ion fusion target studies show that it is possible to achieve ignition with direct drive and energy gain larger than 100 at 1 MJ. To realize these advanced, high-gain schemes based on direct drive, it is necessary to develop a reliable beam smoothing technique to mitigate instabilities and facilitate uniform deposition on the target. The dynamics of the beam centroid can be explored as a possible beam smoothing technique to achieve a uniform illumination over a suitably chosen region of the target. The basic idea of this technique is to induce an oscillatory motion of the centroid for each transverse slice of the beam in such a way that the centroids of different slices strike different locations on the target. The centroid dynamics is controlled by a set of biased electrical plates called “wobblers.” Using a model based on moments of the Vlasov-Maxwell equations, we show that the wobbler deflection force acts only on the centroid motion, and that the envelope dynamics are independent of the wobbler fields. If the conducting wall is far away from the beam, then the envelope dynamics and centroid dynamics are completely decoupled. This is a preferred situation for the beam wobbling technique, because the wobbler system can be designed to generate the desired centroid motion on the target without considering its effects on the envelope and emittance. A conceptual design of the wobbler system for a heavy ion fusion driver is briefly summarized.

The requirements of matching shell ICF target parameters, parameters of compressing, and triggering drivers under direct (fast) ignition are developed. Thin shell target, which represents a shell-ablator with a DT-ice layer, frosted on the inner surface of the shell are considered. Design of a target which ensures the energy supply from the triggering driver to the central part of thermonuclear fuel, in both spherical and cylindrical geometry is developed. Spherical target is furnished with one or two conical channels for the injection of the triggering driver radiation. The ends of the cylindrical target are protected by heavy material walls that have the holes of the radius equal to the final radius of compressed fuel. It was found that the parameters of fast ignition spherical and cylindrical targets, which provide high thermonuclear gain of 500–2000 in the range of the compressing driver energy of 1–10 MJ, may be matched with the drivers parameters at low aspect ratios of the targets, 10–20. The operation of spherical targets at the moderate radius convergence ratio of 15–20, may be provided at the triggering driver energy not higher than 30 kJ. The operation of cylindrical target with spin-oriented DT-fuel at radius convergence ratio of 20–25 may be provided at 150–200 kJ of the triggering driver energy.

Imploding indirect-drive double shell targets may provide an alternative, non-cryogenic path to ignition at the National Ignition Facility (NIF). Experiments are being pursued at OMEGA to understand the hydrodynamics of these implosions and the possibility of scaling it to the NIF design. We have used 40 beams from the OMEGA laser to directly drive the capsules, and we have used the remaining 20 beams to backlight the imploding shells from two different directions at multiple times. We will review the recent experiments to measure the hydrodynamics of the targets using two-view X-ray radiography of the capsules. We will present data on measured yields from the targets. We will present a measured time history of the hydrodynamics of the implosion. Experiments were pursued using direct drive in which the M-band effect (experienced in the indirect drive experiments) could be eliminated or controlled. It was learned in the direct drive experiments that the best performing capsules were those that had a thin outer layer of gold. This effectively causes M-band pre-heat effects giving implosion hydrodynamics and performance closer to the indirect drive case. We will review the methods used to radiograph the targets and the techniques used to extract useful information to compare with calculations. The effect of imperfections in the target construction will be shown to be minimal during the initial stage of implosion. The yields from the targets were observed to be uniformly low compared to indirect-drive.

Popular target designs are reviewed. Possible methods of fusion target fabrication are discussed and the equipment and samples are demonstrated. The properties of the uniform and structured (cluster) materials are considered, showing the advantage of cluster material for energy conversion into soft X rays. The target materials with high content of hydrogen isotopes (BeD2, LiBeD3, or ND3BD3) prove to be more effective for high-power drivers in comparison with beryllium or polyimide.

Bremsstrahlung is one of the most important energy loss mechanisms in achieving ignition, which is only possible above a threshold in temperature for a given fusion reaction and plasma conditions. A detailed analysis of the bremsstrahlung process in degenerate plasma points out that radiation energy loss is much smaller than the value given by the classical formulation. This fact seems not useful to relax ignition requirements in self-ignited targets, because it is only relevant at extremely high densities. On the contrary, it can be very positive in the fast ignition scheme, where the target is compressed to very high densities at a minimum temperature, before the igniting beamlet is sent in.