The paper discusses recent advances in the use of foams in laser–plasma experiments, concerning in particular: (1) the use of foam in order to get an efficient smoothing of laser energy deposition, (2) the problem of hydrodynamics of layered foam-payload targets, (3) the use of foam for shock pressure amplification in equation-of-state experiments, (4) the study of the equation of state of foams in the Megabar regime, and (5) the use of foams for astrophysics relevant experiments, here in particular shock acceleration experiments.

The transport of high-current heavy-ion beams in plasma channels is a promising option for the final transport in a heavy-ion fusion reactor, since it simplifies the construction of the reactor chamber significantly. Our experiments at the Gesellschaft für Schwerionenforschung demonstrate the creation of 1 m long stable plasma channels and the transport of heavy-ion beams. The article outlines the experimental setup used at GSI and reports the results of beam transport measurements using these long channels. The experiments demonstrate good beam transport properties of the channel, indicating that channel transport is a viable alternative to neutralized-ballistic transport.

Hole boring and fast ignition seem to exclude each other: When there is hole boring, no ignition occurs, and vice versa. The laser beam pressure only causes a more or less deep cone-shaped critical surface that leads to better guidance of the beam and to improved laser–plasma coupling. At laser wavelengths of the order of 1 μm, successful fast ignition requires strong anomalous laser beam–pellet coupling.

In the fast ignition scenario for inertial fusion, a relativistic electron beam is supposed to travel from the side of the fusion pellet to its core. One one hand, a relativistic electron beam passing through a plasma is a highly unstable system. On the other hand, the pellet core is denser than its side by four orders of magnitude so that the beam makes its way through a important density gradient. We here investigate the effect of this gradient on the instabilities. It is found that they should develop so early that gradient effects are negligible in the linear phase.

Relatively small-scale laser-driven sources of short wavelength radiation covering a range from the extreme ultraviolet to the hard X-ray regime are now available. Because the duration of the X-ray pulses is comparable to, or shorter than the laser pulse width, it is possible to carry out X-ray measurements with picosecond or femtosecond time resolution.

The application of selective resonant tunneling model is extended from d + t fusion to other light nucleus fusion reactions, such as d + d fusion and d + 3He. In contrast to traditional formulas, the new formula for the cross-section needs only a few parameters to fit the experimental data in the energy range of interest. The features of the astrophysical S-function are derived in terms of this model. The physics of resonant tunneling is discussed.

Using fast imaging technique, the effect of transverse magnetic field on the shape and dynamics of the lithium plasma plume has been studied. Enhancement in the overall emission intensity as well as appearance of distinct structures (lobes) in the plasma plume in the presence of magnetic field has been observed. By introducing a variable magnetic field, the influence of J × B force in expanding plasma plume across the transverse magnetic field has been explored. It appears that J × B force does not has a substantial role in the observed structures in the present case rather different atomic processes, which get affected due to change in plasma parameters, are responsible for appearance of these structures.

The paper reviews and analyses the experiments devoted to the propagation in dense matter of fast electrons produced in the interaction of short-pulse ultra-high-intensity laser pulses with solid density targets.

This paper describes the first results of a feasibility study undertaken at CERN to determine whether a laser-produced plasma can be used as a source of intense highly charged heavy ion beams. A variety of important measurements have been made, and the results are encouraging. Furthermore, a beam of highly charged light ions produced by the laser ion source has been accelerated successfully in a radio frequency quadrupole (RFQ) structure.

Raman backward scattering is investigated in the interaction of linearly polarized ultra short laser pulse with a homogenous cold underdense magnetized plasma by taking into account the relativistic effect and the effect of nonlinearity up to third order. The plasma is embedded in a uniform magnetic field perpendicular to both of propagation direction and electric vector of the radiation field. Nonlinear wave equation is set up and differential equations, which model the instability, are derived. Using of the Fourier transformation, analytical solutions are obtained for a set of physically relevant initial conditions and the temporal growth rate of instability is calculated. Results are significantly different in comparison with lower order computations. The growth rate of backward Raman scattering shows an increase due to the presence of external magnetic field as well as nonlinear effects.

Nonlinear parabolic partial differential equation governing the evolution of complex envelope in slowly varying envelope approximation is solved using variational approach. The basic nonlinear phenomena of relativistic and ponderomotive self-focusing in a plasma are taken into account. Self-focusing, self-phase modulation as well as self-trapping of dark hollow Gaussian beam is studied for higher orders of hollow Gaussian beam (n).

Clusters represent a new class of laser pulse targets which show both the properties of underdense and of overdense plasmas. We present analytical and numerical results (based on 2D- and 3D-PIC simulations) of the Coulomb explosion of the ion cloud that is formed when a cluster is irradiated by a high-intensity laser pulse. For laser pulse intensities in the range of 1021−1022 W/cm2, the laser light can rip electrons from atoms almost instantaneously and can create a cloud made of an electrically nonneutral plasma. Ions can then be accelerated up to high energy during the Coulomb explosion of the cloud.

In this paper, the plasma-filling model was extrapolated to the case of a hohlraum driven by a shaped laser pulse, and this extended model was used to obtain an initial design of the hohlraum size. A density criterion of ne = 0.1 was used for designing hohlraums which have low plasma filling with maximum achievable radiation. The method was successfully used to design a half hohlraum size with a three-step laser pulse on SGIII prototype and a U hohlraum size with shaped laser pulse for ignition. It was shown that the extended model with the criterion can provide reasonable initial design of a hohlraum size for optimal designing with a two-dimensional code.

Electron acceleration by a short high-current relativistic electron bunch (EB) in plasmas at three characteristic densities is studied by particle-in-cell simulation. It is found that if the EB is appropriately matched to the background plasma, the blowout space-charge field of the EB can accelerate the trailing bunch electrons at very high energy gain rate. This high energy gain, as well as the large-amplitude wakefield, the turbulent small-scale electron plasma waves, and the formation of large current peaks, are studied. The evolution of the EB, its blowout field, and other related parameters are shown to be self-similar.

Z pinches have a long and varied history. Beginning in the 18th century, z pinches have been used to heat plasmas very efficiently. Early in the nuclear fusion program, it was realized that modest currents are required to confine plasma that could produce energy gain. The instability of the confined plasma was convincingly demonstrated in experiments in the 1950s that were performed around the world. These uniformly negative results led to z pinches being dropped as a fusion concept. Recent progress in fast z pinches has reinvigorated the field. We review the field and highlight the recent advances that point the way to a bright future for z pinches.

Directed energy and turbulence structure are shown to be crucial in understanding the growth of self-similar Rayleigh–Taylor and incompressible Richtmyer–Meshkov turbulent mixing zones. Averaging over the mixing zone is used to analyze the response of a modified k–ε model and a turbulent two-fluid model. Three different transport regimes are then identified by considering self-similar variable acceleration RT flows (SSVARTs), which appear as promising reference flows for model testing.

Resonant THz radiation generation is proposed by beating of two spatial-triangular laser pulses of different frequencies (ω1, ω2) and wave numbers $\lpar \vec k_1 \comma \; \vec k_2 \rpar $ in plasma having external static magnetic field. Laser pulses co-propagating perpendicular to a dc magnetic field exert a nonlinear ponderomotive force on plasma electrons, imparting them an oscillatory velocity with finite transverse and longitudinal components. Oscillatory plasma electrons couple with periodic density ripples n′ = nq0eiqz to produce a nonlinear current, i.e., responsible for resonantly driving terahertz radiation at $\lpar {\rm \omega} = {\rm \omega} _1 - {\rm \omega} _2 \comma \; \vec k = \vec k_1 - \vec k_2 + \vec q\rpar $. Effects of THz wave frequency, laser beam width, density ripples, and applied magnetic field are studied for the efficient THz radiation generation. The frequency and amplitude of THz radiation were observed to be better tuned by varying dc magnetic field strength and parameters of density ripples (amplitude and periodicity). An efficiency about 0.02 is achieved for laser intensity of 2 × 1015 W/cm2 in a plasma having density ripples about 30%, plasma frequency about 1 THz and magnetic field about 100 kG.

An initial study and design on ignition elliptical hohlraum (ellipraum) is given by using the expended plasma-filling model with criterions. As a result, in an ellipraum with a smaller ratio of major-to-minor axis (a/b), the radius ratio of ellipraum-to-capsule (b/RC) should be larger (hence more sphere-like) to meet the criterions of plasma-filling and laser deposition, meanwhile the required laser energy and peak power are lower and the coupling between different modes is weaker. To produce a 300 eV radiation pulse to ignite a capsule of 1 mm radius, an ellipraum of a/b = 1.6 and b/Rc = 2.8 is superior to a cylinraum with a length-to-diameter ratio of 1.81 and a cylinraum-to-capsule radius ratio of 2.54 in saving more than 10% laser energy and reducing 50% coupling between different modes.

The current trends in stimulated Brillouin scattering and optical phase conjugation are overviewed. This report is formed by the selected papers presented in the “Fifth International Workshop on stimulated Brillouin scattering and phase conjugation 2010” in Japan. The nonlinear properties of phase conjugation based on stimulated Brillouin scattering and photo-refraction can compensate phase distortions in the high power laser systems, and they will also open up potentially novel laser technologies, e.g., phase stabilization, beam combination, pulse compression, ultrafast pulse shaping, and arbitrary waveform generation.

Particle-in-cell (PIC) simulation of a two-foil magnetoinsulated vircator is carried out. Evolution of electron phase portrait has been studied. Formation of two regions with a squeezed state of electron beam is observed, separated from each other by an electronic phase vortex. The power of two-foil vircator's microwave generation was calculated. It is demonstrated that in the phase vortex mode, the power of vircator's microwave radiation may excel the outcome power of a usual one-foil vircator by two times. The spectral characteristics of two-foil vircators were studied. It was found that it is necessary to change the energy of electrons for the variation of primary microwave generation frequency.