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Results for “Laser Inertial Fusion”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Laser driven inertial fusion energy technology development

The future of Laser-Based Inertial fusion energy requires the development of efficient diode-pumped laser drivers that can be scaled to megajoule class output operating at ≥ 10-Hz repetition rate. ARPA-E requested a study of the range of possibilities for a 100kJ/10-Hz laser system with >15% wall-plug efficiency operating below 360 nm. The conceptual design of a compact, 1 kJ class module is presented and analyzed for performance relative to the objectives along with a roadmap to demonstrate the technology.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2025

On-target uniformity of the OMEGA 60-beam inertial confinement fusion laser

Successful direct-drive inertial confinement fusion (ICF) experiments require excellent on-target laser 9 irradiance uniformity maintained over the duration of the pulse. Achieving this symmetry relies on maintaining an 10 energy, power, and fluence balance among all beams in a multibeam laser system. As a result of the improvements 11 described in this paper, the OMEGA 60-beam laser performance has been assessed at approximately 2% on-target 12 irradiance nonuniformity using an updated performance assessment metric that accounts for the laser diagnostic noise 13 floor. The performance is measurement-limited, prompting the need for an improved diagnostic suite. This manuscript 14 provides a comprehensive first-order assessment of extant status of on-target energy, power, and fluence uniformity 15 and explores avenues for improvements.

Diagnostics↗
DOE OSTI2025

Stacked-mosaic amplifier and diode delivery concept for kJ-class inertial fusion energy laser driver

We report on a laser amplifier architecture designed as a modular element for scaling to multi-megajoule laser facilities intended for inertial fusion energy (IFE) power plants. This kilojoule-class module features a stacked mosaic of gain media integrated with a diode delivery system for efficient optical pumping of the mosaic-structured gain medium, enabling high-repetition-rate operation at high wall plug efficiencies, necessary for an IFE driver. Details of a diode delivery system capable of pumping the mosaic architecture are presented. Comprehensive numerical modeling demonstrates that the stacked-mosaic approach reduces transverse gain by five orders of magnitude compared to a conventional full-aperture Yb:YAG based amplifier, substantially suppressing transverse amplified spontaneous emission (TASE) and enabling enhanced longitudinal energy extraction. Detailed analysis of thermal management and wavefront distortion in a 4 × 4 mosaic array indicates that temperature gradients and thermally induced aberrations are effectively controlled using gas cooling and commercially available phase-plate and deformable mirror technologies. We further discuss the applicability of a stacked-mosaic architecture to direct-drive IFE schemes, where broad spectral bandwidth is critical, and its compatibility with frequency conversion modules for up-conversion to blue wavelengths. Finally, an example point design for a 10 kJ, 10 Hz Yb:YAG module operating at 175 K with wall-plug efficiency exceeding 10 % is presented, underscoring the feasibility of this approach for next-generation high-energy lasers for IFE drivers. The results establish the stacked-mosaic amplifier as a scalable, robust platform not only for IFE but also for a broad range of advanced scientific and industrial laser applications.

Lasers↗
DOE OSTI2026

Feature issue introduction: laser driven inertial confinement fusion and bridging the gaps to inertial fusion energy systems

Major fusion research milestones have been achieved using laser driven inertial confinement fusion (ICF) in recent years, and these successes have ignited tremendous enthusiasm for inertial fusion energy (IFE). However, the complexity and difficulty of obtaining fusion ignition with a laser driver in a research setting are often underappreciated, as are the gaps to high driver efficiency, high repetition rates, and laser and target durability requirements needs for IFE. On the academic side, several new research laser systems have been constructed over the past few years, enabling researchers to probe the limits of ICF physics and engineering. This feature issue highlights the challenges and capabilities of laser research and development targeted towards advancing IFE.

Physics - Plasma physics↗
DOE OSTI2025

Physics of laser direct-drive liquid deuterium–tritium wetted foam capsules for inertial confinement fusion

Laser direct-drive liquid deuterium–tritium (DT) wetted foam capsules hold substantial promise for future advancements in inertial confinement fusion (ICF). For this new class of ICF capsules, additive manufacturing (AM) techniques are used to create low aspect ratio spherical shells of a low-density, foam-like CH lattice, which is wetted with cryogenic liquid DT. In the present paper, we discuss key physics issues intrinsic to ignition and burn propagation in laser direct drive wetted foam capsules. These include requirements on laser energy and power, implosion velocity, fuel adiabat, and initial density and dimensions of the CH lattice shell.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2025

A future of inertial confinement fusion without laser-plasma instabilities

From the beginning of inertial confinement fusion (ICF) research, laser-plasma instabilities excited by narrowband lasers have limited the hydrodynamic design space of all laser-based approaches to inertial fusion energy (IFE). With advances in broadband laser technologies, the next generation of ICF drivers will likely have large bandwidth that is engineered to mitigate laser-plasma instabilities, thereby expanding the hydrodynamic design space to include both robust high yields (>200−MJ) with large-energy laser systems (>4 MJ) and high gains (>10) with moderate-energy laser facilities (<2 MJ). State-of-the-art simulations indicate that laser bandwidths of a few percent are required to mitigate instabilities for IFE-relevant conditions. To test these models and demonstrate that high-bandwidth lasers mitigate laser-plasma instabilities, the Fourth-generation Laser for Ultrabroadband eXperiments will be used with the OMEGA Laser System. The goal is to provide the community with the confidence to invest in a multiple-beam high-bandwidth laser facility that will demonstrate the necessary ablation pressures for robust direct-drive ignition without detrimental levels of hot electrons that degrade the implosion performance. It is important to recognize that the highest performing ICF implosions will likely never be completely LPI free because of the significant advantages to maximizing the laser intensity.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2025

Diode laser pumps for future inertial fusion energy systems: status and perspectives

Diode laser pumps are a critical enabling technology for inertial fusion energy (IFE), and will remain the largest contributor to facility cost, even assuming tenfold cost-reduction at high volumes. An overview of diode requirements for IFE and a technology path to achieve them are presented.

Engineering - Electronic and electrical engineerin↗
DOE OSTI2025

Status and prospects for inertial fusion energy via lasers

Fusion energy is the ultimate clean and limitless energy source, but its development requires overcoming many scientific and technological challenges. For the first time in the 60-year long history of fusion research, ignition and target gain above unity (G>1) were demonstrated in the laboratory at the National Ignition Facility at the Lawrence Livermore National Laboratory in 2022. Turning laser fusion into an energy source requires that the results from single shot experiments be replicated at much higher repetition rates of many shots per second to produce high average power at relatively low cost. Furthermore, this requires the development of new laser technologies, mass production of suitable targets, accurate injection and tracking systems and new materials for the reactor chamber components and final optics. Ultra broadband and deep UV light are laser advances that can dramatically improve the laser energy coupling to the target thereby reducing the laser energy and power requirements.

Fusion energy↗
DOE OSTI2026

Wetted-foam target stability for laser-direct-drive inertial confinement fusion

Using highly resolved three-dimensional radiation-hydrodynamic simulations, the effects of wetted-foam (WF) ablators in direct-drive inertial confinement fusion cryogenic implosions on the OMEGA laser were investigated. The performance of these implosions was compared with that of implosions using targets with solid-plastic ablators. Simulations considering WF ablators as a homogeneous material show no mitigation of the effects of laser imprint, where the absence of this mitigation can be attributed to the use of picket pulses. Heterogeneous random-structure WF ablators introduce large short-wavelength perturbations, which are seeded by WF inhomogeneities. These perturbations exceed the perturbations seeded by the imprint and cause an additional reduction in implosion performance when the average pore size in the WF exceeds ~0.2 μm. Foam-seeded perturbations are expected to be less damaging in more stable high-adiabat (⁠ ≳ 5⁠) implosions. Here, the perturbations introduced by the WF ablators can be substantially reduced by using a foam matrix with a layered structure instead of a random one. Further study of the effects of WFs in ignition designs of the MJ laser energy scale is required in the perspective of future inertial fusion energy mass production.

Igumenshchev, I. V. [University of Rochester, NY (↗
DOE OSTI2025

Laser wavelength dependence of laser imprint

In laser direct-drive inertial confinement fusion, laser imprint is one of the major causes of degradation in target performance through its seeding of hydrodynamic instabilities. Early experiments and simulations have shown that laser imprint could be mitigated with a longer laser wavelength because of its lower critical density and longer conduction zone. Building upon this work, we explore a scenario where the laser wavelength during the picket pulse differs from that of the main pulse in order to gain the benefit of reduced imprint, while avoiding losses in drive coupling efficiency or an increase in laser-plasma instabilities. A series of 2D radiation-hydrodynamic simulations, which test three different laser wavelengths for the picket pulse, has been performed, where the intensity of the picket pulse is adjusted in order to maintain the same implosion adiabat. A detailed analysis of the growth of the mass density modulations at the ablation front over a large range of mode numbers confirms that the laser imprint can be mitigated with a picket pulse operating at a longer wavelength than the main pulse because of the longer conduction zone and enhanced thermal smoothing. The amplitude of the ablation front modulations is found to be lower for all mode numbers, which reduces the seeding of the Rayleigh–Taylor instability without affecting the mode growth rates.

Fourier analysis↗
DOE OSTI2026

Spherical compression of an applied magnetic field in inertial confinement fusion

Applying an external magnetic field to laser-driven inertial confinement fusion implosions is a promising approach for enhancing fusion yield. The field is compressed with the plasma, producing a magnetized hotspot that anisotropically suppresses thermal losses and traps alpha particles, making performance sensitive to the compressed field orientation. Here, we derive a simple, readily applicable analytic model that enables rapid evaluation of the compressed field topology and show that ablation into the hotspot amplifies the central field, while the ablated ice near the hotspot edge develops a decaying, radially bent field, with a discontinuity in the field direction. The radially bent field renders thermal insulation at the hotspot edge negligible and largely independent of the applied field strength, whereas insulation in the hotspot core still depends strongly on the applied field. Applying the model to non-axial initial field configurations, we find that an initially applied mirror field provides the greatest suppression, followed by the standard axial field.

Physics - Plasma physics↗
DOE OSTI2026

Demonstration of Control of Laser-Plasma Instabilities in the Laboratory Using STUD Pulses (Spike Trains of Uneven Duration and Delay)

The success of laser Driven Inertial Fusion Technology (LaDrIFT) hinges on controlling laser-plasma instabilities (LPI) for effective and non-deleterious energy coupling, together with the control of implosion hydrodynamic instabilities (IHI) for target integrity. Conventional approaches ignore LPI and focus on IHI. LPI control suggests the use of low intensities, short wavelengths, and thus the slow implosions of thinner shells, while IHI control calls for thicker shells, fast implosions and thus at higher laser intensities and ablation pressures. These contradicting requirements severely restrict LaDrIFT design space, flexibility and scalability. This program demonstrates, with theoretical designs and their preliminary experimental realizations, that STUD pulses (Spike Trains of Uneven Duration and Delay) can control LPI in high-energy-density (HED) laser-created plasmas and explore this physics for the first time with high repetition (rep) rate lasers.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2025

Experimental and numerical evaluation of laser shinethrough in polystyrene at 3 ω and 4 ω laser frequencies

In laser-direct-drive inertial confinement fusion (ICF), laser shinethrough is the process associated with laser propagation through the target plastic ablator, polystyrene is often used in ICF experiments, and leads to energy deposition in the target until the critical density is established at the ablator front surface. This process causes material modifications that may change the shock propagation and lead to density and pressure perturbations at the interface between the polystyrene and cryogenic deuterium-tritium (DT) layer. This work reports on experimental observations and numerical investigations of laser shinethrough at the third and the fourth harmonic of ICF class laser systems (1 ω corresponds to a wavelength of ∼1.06 μm ). The experiments evidence that, at 4 ω , the laser is absorbed over a distance of about a few microns and laser shinethrough is completely eliminated in contrast with the behavior at 3 ω . These experimental observations are reproduced by numerical simulations. The laser fluence required to reach the critical density at the ablator front surface is also found to be more than one order of magnitude higher at the third harmonic. Finally, modeling suggests that the back surface of the ablator exhibits ion temperatures greater than the melting temperature of cryogenic DT and electron pressure larger than the bulk and shear moduli of cryogenic DT for the case of using a 3 ω laser.

Pineau, A. [Univ. of Rochester, NY (United States)↗
DOE OSTI2026

LaserNetUS: A Proposal to Advance North America’s First High Intensity Laser Research Network Final Report

LaserNetUS Collaborative Network established in 2018 is a network of high-power laser facilities supported by the Department of Energy (DOE) Office of Fusion Energy Sciences (FES) and operating effectively as a user facility. Its mission is to advance and promote intense laser science and applications by providing scientists and students with broad access to unique facilities and enabling technologies, advancing the frontiers of laser-science research, and fostering collaboration among researchers and networks from around the world. Users who submit proposals through an annual call are selected by an external and independent proposal review panel (PRP) not involving personnel from any of the facilities.

36 MATERIALS SCIENCE↗
DOE OSTI2025

Distortions in charged-particle images of laser direct-drive inertial confinement fusion implosions

Energetic charged particles generated by inertial confinement fusion (ICF) implosions encode information about the spatial morphology of the hotspot and dense fuel during the time of peak fusion reactions. The knock-on deuteron imager (KoDI) was developed at the Omega Laser Facility to image these particles in order to diagnose low-mode asymmetries in the hotspot and dense fuel layer of cryogenic deuterium–tritium ICF implosions. However, the images collected are distorted in several ways that prevent reconstruction of the deuteron source. In this paper, we describe these distortions and a series of attempts to mitigate or compensate for them. We present several potential mechanisms for the distortions, including a new model for scattering of charged particles in filamentary electric or magnetic fields surrounding the implosion. Particle-tracing is used to create synthetic KoDI data based on the filamentary field model that reproduces the main experimentally observed image distortions. We conclude that the filamentary scattering model best matches the observed image distortions. Finally, we discuss potential impacts of filamentary fields on other charged-particle diagnostics.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗