On behalf of all at High Power Laser Science and Engineering we would like to congratulate the team at Lawrence Livermore National Laboratory (LLNL) on demonstrating fusion ignition at the National Ignition Facility. This major scientific achievement was realized on the 5 December 2022 at the LLNL and announced at a press briefing on the 13 December 2022 by the United States Department of Energy’s National Nuclear Security Administration. This was a historic milestone and the culmination of decades of effort.

In inertial fusion energy (IFE) research, a number of technological issues have focused on the ability to inexpensively fabricate large quantities of free-standing targets (FSTs) by developing a specialized layering module with repeatable operation. Of central importance for the progress towards plasma generation with intense thermonuclear reactions is the fuel structure, which must be isotropic to ensure that fusion will take place. In this report, the results of modeling the FST layering time, $\unicode[STIX]{x1D70F}_{\text{Form}}$, are presented for targets which are shells of ${\sim}4~\text{mm}$ in diameter with a wall made from compact and porous polymers. The layer thickness is ${\sim}200~\unicode[STIX]{x03BC}\text{m}$ for pure solid fuel and ${\sim}250~\unicode[STIX]{x03BC}\text{m}$ for in-porous solid fuel. Computation shows $\unicode[STIX]{x1D70F}_{\text{Form}}<23$  s for $\text{D}_{2}$ fuel and $\unicode[STIX]{x1D70F}_{\text{Form}}<30$  s for D–T fuel. This is an excellent result in terms of minimizing the tritium inventory, producing IFE targets in massive numbers (${\sim}$1 million each day) and obtaining the fuel as isotropic ultrafine layers. It is shown experimentally that such small layering time can be realized by the FST layering method in line-moving, high-gain direct-drive cryogenic targets using $n$-fold-spiral layering channels at $n=2,3$.

In inertial fusion energy (IFE) research, a considerable attention has recently been focused on the issue of large target fabrication for MJ-class laser facilities. The ignition and high-gain target designs require a condensed uniform layer of hydrogen fuel on the inside of a spherical shell. In this report, we discuss the current status and further trends in the area of developing the layering techniques intended to produce ignition, and layering techniques proposed to high repetition rate and mass production of IFE targets.

Laser drivers are an enabling factor to inertial confinement fusion, because laser diodes must be used instead of flash lamps. We discuss the limitations of laser diode arrays and show what steps the industry is taking. The pump power requirements of large-scale projects such as LIFE or HiPER are within reach of semiconductor laser diode assemblies. Pulsed light output powers per laser bars have been around 300 W per bar, as in the Jenoptik 940 nm bars previously used for pumping the Yb:YAG slabs in the DiPOLE project. By redesigning the semiconductor laser structures 500 W per bar is now commercially available for 808, 880 and 940 nm pump wavelengths. The construction of one inertial fusion power plant will require an amount of semiconductor laser chips in excess of the current annual production by two orders of magnitude. This adds to the engineering task of improving the device characteristics a challenge to production capacity. While the industry benefits from the recent boost in solid-state lighting that acts as a technology driver, cooperation between manufacturers will be imperative, and to this end we propose standardization efforts.

As our understanding of the environmental impact of fossil fuel based energy production increases, it is becoming clear that the world needs a new energy solution to meet the challenges of the future. A transformation is required in the energy market to meet the need for low carbon, sustainable, affordable generation matched with security of supply. In the short term, an increasing contribution from renewable sources may provide a solution in some locations. In the longer term, low carbon, sustainable solutions must be developed to meet base load energy demand, if the world is to avoid an ever increasing energy gap and the attendant political instabilities. Laser-driven inertial fusion energy (IFE) may offer such a solution.

Fast ignition of inertial fusion targets driven by quasi-monoenergetic ion beams is investigated by means of numerical simulations. Light and intermediate ions such as lithium, carbon, aluminum and vanadium have been considered. Simulations show that the minimum ignition energies of an ideal configuration of compressed Deuterium-Tritium are almost independent on the ion atomic number. However, they are obtained for increasing ion energies, which scale, approximately, as Z2, where Z is the ion atomic number. Assuming that the ion beam can be focused into 10 µm spots, a new irradiation scheme is proposed to reduce the ignition energies. The combination of intermediate Z ions, such as 5.5 GeV vanadium, and the new irradiation scheme allows a reduction of the number of ions required for ignition by, roughly, three orders of magnitude when compared with the standard proton fast ignition scheme.

Unconventional, promising approaches to inertial fusion energy (IFE) proposed and studied in the framework of IFE keep-in-touch activity at Frascati EURATOM-ENEA Association will be reconsidered for the present more advanced technological context associated to a planned large installations scenario. Then the possibility to generate laser-produced fast heavy-ion sources (e.g., Bi ions, tens GeV) will be explored taking as reference results obtained in the FIGEX experiment scaled toward thermonuclear regimes. A possible dimensioning of such sources will be also given as well as the associated laser requirements.

An approach to produce efficient and economical hydrogen, which is one of the solutions of future energy, by inertial fusion energy reactor is discussed. This fusion reactor is with magnetic field such as mirror machine and graphite solid blanket. Neutrons and charged particles from nuclear reactions are separated from each other by this magnetic field. This results in hydrogen production efficiently in a solid blanket of high temperature with a breakeven of electricity by direct conversion of charged particle. The output of hydrogen may meet not only economical issue but also ecological issues.

The 70-year anniversary of the first nuclear fusion reaction of hydrogen isotopes by Oliphant, Harteck, and Rutherford is an opportunity to realize how beam fusion is the path for energy production, including both branches, the magnetic confinement fusion and the inertial fusion energy (IFE). It is intriguing that Oliphant's basic concept for igniting controlled fusion reactions by beams has made a comeback even for magnetic confinement plasma, after this beam fusion concept was revealed by the basically nonlinear processes of the well-known alternative of inertial confinement fusion using laser or particle beams. After reviewing the main streams of both directions some results are reported—as an example of possible alternatives—about how experiments with skin layer interaction and avoiding relativistic self-focusing of clean PW–ps laser pulses for IFE may possibly lead to a simplified fusion reactor scheme without the need for special compression of solid deuterium–tritium fuel.

Experiments of heating of solid targets by fast electrons have been analyzed by means of simulations with a recently developed hybrid code. Electron propagation, refluxing effects, relative importance of self-generated fields, and heating of targets are presented. We found a good agreement between simulations and experiments on the Kα yield.

The article presents the multigroup kinetic approximation of radiation transport in hohlraum systems. The view factor-based method of numerical solution is proposed. Its advantages are a detailed account of the problem geometry and accurate handling of the solution angular anisotropy and discontinuities. The method is computationally efficient and easily parallelizable. Coupled to the kinetic + hydro description of the wall dynamics, it represents a powerful tool for integrated investigation of the systems with strongly inhomogeneous optical properties.

The Rayleigh–Taylor instability (RTI) of a laser-accelerated ablative surface of a thin plasma layer in an inertial fusion energy (IFE) target with incompressible electrically conducting plasma in the presence of a transverse magnetic field is investigated using linear stability analysis. A simple theory based on Stokes-lubrication approximation is proposed. It is shown that the effect of a transverse magnetic field is to reduce the growth rate of RTI considerably over the value it would have in the absence of a magnetic field. This is useful in the extraction of IFE efficiently.

The High Current Experiment (HCX) is being assembled at Lawrence Berkeley National Laboratory as part of the U.S. program to explore heavy ion beam transport at a scale representative of the low-energy end of an induction linac driver for fusion energy production. The primary mission of this experiment is to investigate aperture fill factors acceptable for the transport of space-charge dominated heavy ion beams at high space-charge intensity (line-charge density ∼ 0.2 μC/m) over long pulse durations (>4 μs). This machine will test transport issues at a driver-relevant scale resulting from nonlinear space-charge effects and collective modes, beam centroid alignment and beam steering, matching, image charges, halo, lost-particle induced electron effects, and longitudinal bunch control. We present the first experimental results carried out with the coasting K+ ion beam transported through the first 10 electrostatic transport quadrupoles and associated diagnostics. Later phases of the experiment will include more electrostatic lattice periods to allow more sensitive tests of emittance growth, and also magnetic quadrupoles to explore similar issues in magnetic channels with a full driver scale beam.