National Ignition Facility Ignition Research Articles

Data-driven prediction of scaling and ignition of inertial confinement fusion experiments

Recent advances in inertial confinement fusion (ICF) at the National Ignition Facility (NIF), including ignition and energy gain, are enabled by a close coupling between experiments and high-fidelity simulations. Neither simulations nor experiments can fully constrain the behavior of ICF implosions on their own, meaning pre- and postshot simulation studies must incorporate experimental data to be reliable. Linking past data with simulations to make predictions for upcoming designs and quantifying the uncertainty in those predictions has been an ongoing challenge in ICF research. We have developed a data-driven approach to prediction and uncertainty quantification that combines large ensembles of simulations with Bayesian inference and deep learning. The approach builds a predictive model for the statistical distribution of key performance parameters, which is jointly informed by past experiments and physics simulations. The prediction distribution captures the impact of experimental uncertainty, expert priors, design changes, and shot-to-shot variations. We have used this new capability to predict a 10× increase in ignition probability between Hybrid-E shots driven with 2.05 MJ compared to 1.9 MJ, and validated our predictions against subsequent experiments. We describe our new Bayesian postshot and prediction capabilities, discuss their application to NIF ignition and validate the results, and finally investigate the impact of data sparsity on our prediction results.

Bayesian batch optimization for molybdenum versus tungsten inertial confinement fusion double shell target design

AbstractAccess to reliable, clean energy sources is a major concern for national security. Much research is focused on the “grand challenge” of producing energy via controlled fusion reactions in a laboratory setting. For fusion experiments, specifically inertial confinement fusion (ICF), to produce sufficient energy, the fusion reactions in the ICF fuel need to become self‐sustaining and burn deuterium‐tritium (DT) fuel efficiently. The recent record‐breaking NIF ignition shot was able to achieve this goal as well as produce more energy than used to drive the experiment. This achievement brings self‐sustaining fusion‐based power systems closer than ever before, capable of providing humans with access to secure, renewable energy. In order to further progress toward the actualization of such power systems, more ICF experiments need to be conducted at large laser facilities such as the United States's National Ignition Facility (NIF) or France's Laser Mega‐Joule. The high cost per shot and limited number of shots that are possible per year make it prohibitive to perform large numbers of experiments. As such, experimental design relies heavily on complex predictive physics simulations for high‐fidelity “preshot” analysis. These multidimensional, multi‐physics, high‐fidelity simulations have to account for a variety of input parameters as well as modeling the extreme conditions (pressures and densities) present at ignition. Such simulations (especially in 3D) can become computationally prohibitive to turn around for each ICF experiment. In this work, we explore using Bayesian optimization with Gaussian processes (GPs) to find optimal designs for ICF double shell targets, while keeping computational costs to manageable levels. These double shell targets have an inner shell that grades from beryllium on the outer surface to the higher Z material molybdenum, as opposed to the nominally used tungsten, on the inside in order to trade off between the high performance associated with high density inner shells and capsule stability. We describe our results for “capsule‐only” xRAGE simulations to study the physics between different capsule designs, inner shell materials, and potential for future experiments.

What Machine Learning Can and Cannot Do for Inertial Confinement Fusion

Machine learning methodologies have played remarkable roles in solving complex systems with large data, well-defined input–output pairs, and clearly definable goals and metrics. The methodologies are effective in image analysis, classification, and systems without long chains of logic. Recently, machine-learning methodologies have been widely applied to inertial confinement fusion (ICF) capsules and the design optimization of OMEGA (Omega Laser Facility) capsule implosion and NIF (National Ignition Facility) ignition capsules, leading to significant progress. As machine learning is being increasingly applied, concerns arise regarding its capabilities and limitations in the context of ICF. ICF is a complicated physical system that relies on physics knowledge and human judgment to guide machine learning. Additionally, the experimental database for ICF ignition is not large enough to provide credible training data. Most researchers in the field of ICF use simulations, or a mix of simulations and experimental results, instead of real data to train machine learning models and related tools. They then use the trained learning model to predict future events. This methodology can be successful, subject to a careful choice of data and simulations. However, because of the extreme sensitivity of the neutron yield to the input implosion parameters, physics-guided machine learning for ICF is extremely important and necessary, especially when the database is small, the uncertain-domain knowledge is large, and the physical capabilities of the learning models are still being developed. In this work, we identify problems in ICF that are suitable for machine learning and circumstances where machine learning is less likely to be successful. This study investigates the applications of machine learning and highlights fundamental research challenges and directions associated with machine learning in ICF.

A “polar contact” tent for reduced perturbation and improved performance of NIF ignition capsules

In indirectly driven Inertial Confinement Fusion implosions conducted on the National Ignition Facility (NIF), the imploding capsule is supported in a laser-heated radiation enclosure (called a “hohlraum”) by a pair of very thin (∼15–45 nm) plastic films (referred to as a “tent”). Even though the thickness of these tents is a small fraction of that of the spherical capsule ablator (∼165 μm), both numerical simulations as well as experiments indicate that this capsule support mechanism results in a large areal density (ρR) perturbation on the capsule surface at the contact point where the tent departs from the capsule. As a result, during deceleration of the deuterium-tritium (DT) fuel layer, a jet of the dense ablator material penetrates and cools the fuel hot spot, significantly degrading the neutron yield (resulting in only ∼10%–20% of the unperturbed 1-D yield). In this article, we present a hypothesis and supporting design simulations of a new “polar contact” tent support system, which reduces the contact area between the tent and the capsule and results in a significant improvement in the capsule performance. Simulations predict a ∼70% increase in neutron yield over that for an implosion with a traditional tent support. An initial demonstration experiment was conducted on the NIF and produced highest ever recorded primary DT neutron yield among all layered DT implosions with plastic ablators on the NIF, though more experiments are needed to comprehensively study the effect of the polar tent on implosion performance.

Analysis of hohlraum energetics of the SG series and the NIF experiments with energy balance model

The basic energy balance model is applied to analyze the hohlraum energetics data from the Shenguang (SG) series laser facilities and the National Ignition Facility (NIF) experiments published in the past few years. The analysis shows that the overall hohlraum energetics data are in agreement with the energy balance model within 20% deviation. The 20% deviation might be caused by the diversity in hohlraum parameters, such as material, laser pulse, gas filling density, etc. In addition, the NIF's ignition target designs and our ignition target designs given by simulations are also in accordance with the energy balance model. This work confirms the value of the energy balance model for ignition target design and experimental data assessment, and demonstrates that the NIF energy is enough to achieve ignition if a 1D spherical radiation drive could be created, meanwhile both the laser plasma instabilities and hydrodynamic instabilities could be suppressed.

Cryogenic Target System for Hydrogen Layering

A cryogenic target positioning system was designed and installed on the National Ignition Facility (NIF) target chamber. This instrument incorporates the ability to fill, form, and characterize the NIF targets with hydrogen isotopes needed for ignition experiments inside the NIF target bay then transport and position them in the target chamber. This effort brought to fruition years of research in growing and metrologizing high-quality hydrogen fuel layers and landed it in an especially demanding operations environment in the NIF facility. D-T (deuterium-tritium) layers for NIF ignition experiments have extremely tight specifications and must be grown in a very highly constrained environment: a NIF ignition target inside a cryogenic target positioner inside the NIF target bay. Exquisite control of temperature, pressure, contaminant level, and thermal uniformity are necessary throughout seed formation and layer growth to create an essentially-groove-free single crystal layer.The team developed processes, procedures, software, and metrology techniques to form and qualify solid layers of hydrogen isotopes at a quality level and yield needed to support the National Ignition Campaign experimental program. The team has grown over 220 layers in NIF, and 52 have been shot to date.

Production Manufacturing of Gold-Depleted Uranium Layered Hohlraums for the National Ignition Facility

By making the hohlraum wall more opaque to the driver energy, the efficiency of X-ray conversion is improved with the addition of depleted uranium (DU) to a gold-only hohlraum [see T. J. Orzechowski et al., Phys. Rev. Lett., Vol. 77, p. 3545 (1996)]. The National Ignition Facility (NIF) point design for ignition requires a DU hohlraum, which is manufactured by General Atomics. The process of creating a hohlraum with multiple layers presents manufacturing challenges. To produce these components many steps are required. The processes for manufacturing an Au-lined DU hohlraum requires single-point diamond turning, sputter deposition, electroplating, chemical etch, and cleaning. These steps combined make a process that yields a fully intact Au-DU layered NIF ignition hohlraum.

Production Manufacturing of Gold-Depleted Uranium Layered Hohlraums for the National Ignition Facility

By making the hohlraum wall more opaque to the driver energy, the efficiency of X-ray conversion is improved with the addition of depleted uranium (DU) to a gold-only hohlraum [see T. J. Orzechowski et al., Phys. Rev. Lett., Vol. 77, p. 3545 (1996)]. The National Ignition Facility (NIF) point design for ignition requires a DU hohlraum, which is manufactured by General Atomics. The process of creating a hohlraum with multiple layers presents manufacturing challenges. To produce these components many steps are required. The processes for manufacturing an Au-lined DU hohlraum requires single-point diamond turning, sputter deposition, electroplating, chemical etch, and cleaning. These steps combined make a process that yields a fully intact Au-DU layered NIF ignition hohlraum.

Advances in HYDRA and its applications to simulations of inertial confinement fusion targets

A new set of capabilities has been implemented in the HYDRA 2D/3D multiphysics inertial confinement fusion simulation code. These include a Monte Carlo particle transport library. It models transport of neutrons, gamma rays and light ions, as well as products they generate from nuclear and coulomb collisions. It allows accurate simulations of nuclear diagnostic signatures from capsule implosions. We apply it to here in a 3D simulation of a National Ignition Facility (NIF) ignition capsule which models the full capsule solid angle. This simulation contains a severely rough ablator perturbation and provides diagnostics signatures of capsule failure due to excessive instability growth. 1. INTRODUCTION Simulations of indirect drive ignition target designs for the National Ignition Facility (NIF) must model asymmetries originating from a wide variety of sources. These include intrinsic drive asymmetries due to the illumination geometry, and extrinsic asymmetries resulting from pointing and power balance errors between the beams. Roughness on the shell surfaces seed hydrodynamic instabilities which can also degrade capsule performance. These include discrete features such as ice grooves, dust grains, unusually large isolated bumps and the fill tube used to inject fuel into the capsule. The growth factors due to hydrodynamic instabilities are sufficiently large that perturbations progress into the nonlinear saturated regime. Experiments and simulations have established that larger saturation amplitudes are obtained by symmetric 3D perturbation shapes (1-10). In addition the various asymmetries can combine in a capsule implosion so that accurate treatment of the phases between them is essential. Treating accurately the effects of these asymmetries on capsule performance and their manifestation in simulated diagnostics requires 3D simulation (11). Previously we reported results from 3-D integrated simulations of the full ignition target and high resolution simulations of a capsule over a limited solid angle (12-14). Here we report the first high resolution 3D simulation of a full implosion of a NIF ignition capsule carried out over the full 4 solid angle. The simulation includes a Monte Carlo treatment of the burn product transport, enabling simulation of neutron diagnostics.

Advances in target design and fabrication for experiments on NIF

The ability to build target platforms for National Ignition Facility (NIF) is a key feature in LANL's (Los Alamos National Laboratory) Target Fabrication Program. We recently built and manufactured the first LANL targets to be fielded on NIF in March 2011. Experiments on NIF require precision component manufacturing and accurate knowledge of the materials used in the targets. The characterization of foams and aerogels, the Be ignition capsule, and machining unique components are of main material focus. One important characterization metric the physics' have determined is that the knowledge of density gradients in foams is important. We are making strides in not only locating these density gradients in aerogels and foams as a result of how they are manufactured and machined but also quantifying the density within the foam using 3D confocal micro x-ray fluorescence (XRF) imaging and 3D x-ray computed tomography (CT) imaging. In addition, collaborative efforts between General Atomics (GA) and LANL in the characterization of the NIF Ignition beryllium capsule have shown that the copper in the capsule migrates radially from the capsule center. 1. ELEMENTAL DIFFUSION THROUGH IGNITION CAPSULES Recent collaborations with LANL and General Atomics (GA) have focused on analysis of ignition capsules, specifically elemental migration throughout the ignition capsules. Currently, the leading choice in the point design for the ignition capsules are graded doped Cu-Be capsules with the secondary design being Ge doped CH capsules. Both of these capsule types were analyzed using 3D confocal XRF imaging and 3D x-ray CT imaging for possible elemental migration. 1.1 Analysis of copper migration in graded doped Cu-Be ignition capsules Previous studies at GA using contact radiography indicated migration of the Cu dopant in the capsule shell. In addition, SEM (scanning electron microscopy) images of pre- and post-pyrolysis indicates formation of domes on the surface of the capsules post-pyrolysis. We believe this is due to thermal migration of copper during the pyrolysis step. It is well known and documented in materials science literature that copper readily migrates when subjected to higher thermal conditions. (1) Since the dome features are seen on the capsule surface after pyrolysis, we believe these domes are that of copper migrating to the surface. To determine if the Cu migration occurred radially throughout the capsule, a few ignition capsules were given to LANL to study. Using a combination of 3D x-ray CT imaging and

A new approach to foam-lined indirect-drive NIF ignition targets

Taking full advantage of the unique laboratory environment created by the National Ignition Facility (NIF) will require the availability of foam-lined indirect-drive inertial confinement fusion targets. Here, we report on a new approach that enables fabrication of target structures that consist of a thin-walled (<30 µm) ultra-low-density (<30 mg cm−3) hydrocarbon foam film inside a thick-walled, ∼2 mm diameter ablator shell. In contrast to previous work on direct-drive targets that started with the fabrication of foam shells, we use a prefabricated ablator as a mold to cast the foam liner within the shell. This work summarizes crucial components of this new approach, including the aerogel chemistry, filling of the ablator shell with the aerogel precursor solution with nanolitre precision, creating uniform polymer gel coatings inside the ablator capsule, supercritical drying and doping.

Experimental demonstration of early time, hohlraum radiation symmetry tuning for indirect drive ignition experiments

Early time radiation symmetry at the capsule for indirect drive ignition on the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Nucl. Fusion 44, 228 (2004)] will be inferred from the instantaneous soft x-ray re-emission pattern of a high-Z sphere replacing the ignition capsule. This technique was tested on the OMEGA laser facility [J. M. Soures, R. L. McCrory, T. Boehly et al., Laser Part. Beams 11, 317 (1991)] in near full ignition scale vacuum hohlraums using an equivalent experimental setup to the one planned for NIF. Two laser cones entering each laser entrance hole heat the hohlraums to radiation temperatures of 100 eV, mimicking the NIF ignition pulse foot drive. The experiments have demonstrated accuracies of ±1.5% (±2%) in inferred P2/P0 (P4/P0) Legendre mode incident flux asymmetry and consistency between 900 eV and 1200 eV re-emission patterns. We have also demonstrated the expected tuning capability of P2/P0, from positive (pole hot) to negative (waist hot), decreasing linearly with the inner/outer beams power fraction. P4/P0 on the other hand shows very little variation with power fraction. We developed a simple analytical viewfactor model that is in good agreement with both measured P2/P0 and P4/P0 and their dependence on inner beam power fraction.

Short-wavelength and three-dimensional instability evolution in National Ignition Facility ignition capsule designs

Ignition capsule designs for the National Ignition Facility (NIF) [G. H. Miller, E. I. Moses, and C. R. Wuest, Opt. Eng. 443, 2841 (2004)] have continued to evolve in light of improved physical data inputs, improving simulation techniques, and, most recently, experimental data from a growing number of NIF sub-ignition experiments. This paper summarizes a number of recent changes to the cryogenic capsule design and some of our latest techniques in simulating its performance. Specifically, recent experimental results indicated harder x-ray drive spectra in NIF hohlraums than were predicted and used in previous capsule optimization studies. To accommodate this harder drive spectrum, a series of high-resolution 2-D simulations, resolving Legendre mode numbers as high as 2000, were run and the germanium dopant concentration and ablator shell thicknesses re-optimized accordingly. Simultaneously, the possibility of cooperative or nonlinear interaction between neighboring ablator surface defects has motivated a series of fully 3-D simulations run with the massively parallel HYDRA code. These last simulations include perturbations seeded on all capsule interfaces and can use actual measured shell surfaces as initial conditions. 3-D simulations resolving Legendre modes up to 200 on large capsule sectors have run through ignition and burn, and higher resolution simulations resolving as high as mode 1200 have been run to benchmark high-resolution 2-D runs. Finally, highly resolved 3-D simulations have also been run of the jet-type perturbation caused by the fill tube fitted to the capsule. These 3-D simulations compare well with the more typical 2-D simulations used in assessing the fill tube’s impact on ignition. Coupled with the latest experimental inputs from NIF, our improving simulation capability yields a fuller and more accurate picture of NIF ignition capsule performance.

The National Ignition Facility and the Promise of Inertial Fusion Energy

The National Ignition Facility (NIF) at the Lawrence Livermore National Laboratory (LLNL) in Livermore, CA, is now operational. The NIF is the world’s most energetic laser system capable of producing 1.8 MJ and 500 TW of ultraviolet light. By concentrating the energy from its 192 extremely energetic laser beams into a mm3-sized target, NIF can produce temperatures above 100 million K, densities of 1,000 g/cm3, and pressures 100 billion times atmospheric pressure - conditions that have never been created in a laboratory and emulate those in planetary interiors and stellar environments. On September 29, 2010, the first integrated ignition experiment was conducted, demonstrating the successful coordination of the laser, cryogenic target system, array of diagnostics and infrastructure required for ignition demonstration. In light of this strong progress, the U.S. and international communities are examining the implication of NIF ignition for inertial fusion energy (IFE). A laser-based IFE power plant will require a repetition rate of 10–20 Hz and a laser with 10% electrical-optical efficiency, as well as further development and advances in large-scale target fabrication, target injection, and other supporting technologies. These capabilities could lead to a prototype IFE demonstration plant in the 10- to 15-year time frame. LLNL, in partnership with other institutions, is developing a Laser Inertial Fusion Engine (LIFE) concept and examining in detail various technology choices. This paper will describe the unprecedented experimental capabilities of the NIF and the results achieved so far on the path toward ignition. The paper will conclude with a discussion about the need to build on the progress on NIF to develop an implementable and effective plan to achieve the promise of LIFE as a source of carbon-free energy.

Improvements to Fill Tube Design for Direct-Drive NIF and Fast Ignition Applications

Fill tubes are being implemented to meet direct-drive National Ignition Facility (NIF) target designs and eliminate the need for permeation filling of targets. Significant improvements have been made to the fill tube designs for the NIF-scale CD and fast ignition targets to accommodate fuel-layering experiments at the University of Rochester Laboratory for Laser Energetics. The initial fill tube design had a number of issues that contributed to the nonuniformity of the deuterium (D2) ice layer and low fabrication yield of targets. Redesign of the entire target has significantly improved the D2 ice layering by reducing thermal perturbations. These design changes also made a more robust target that can survive the handling required in fabrication and testing. This paper will detail the target design aspects that were altered, including adjusting the fill tube aspect ratio, removing the thermally conductive support stalk, and adding a thermally conductive coating on the fill tube.

Deuterium-Tritium Fuel Layer Formation for the National Ignition Facility

Inertial confinement fusion requires very smooth and uniform solid deuterium-tritium (D-T) fuel layers. The National Ignition Facility (NIF) point design calls for a 65- to 75-μm-thick D-T fuel layer inside of a 2-mm-diam spherical ablator shell to be 1.5 K below the D-T melting temperature (Tm) of 19.79 K. We find that the layer quality depends on the initial crystal seeding, with the best layers grown from a single seed. The low modes of the layer are controlled by thermal shimming of the hohlraum and meet the NIF requirement with beryllium shells and nearly meet the requirement with plastic shells. The remaining roughness is localized in grain-boundary grooves and is minimal for a single crystal layer. Once formed, the layers need to be cooled to Tm - 1.5 K. We have studied dependence of the roughness on the cooling rate and found that cooling at rates of 0.03 to 0.5 K/s is able to preserve the layer structure for a few seconds after reaching the desired temperature. The entire fuel layer remains in contact with the shell during this rapid cooling. Thus, rapid cooling of the layers is able to satisfy the NIF ignition requirements.

NIF Ignition Target Requirements, Margins, and Uncertainties: Status February 2010

Targets intended to produce ignition on the National Ignition Facility (NIF) are being simulated, and the simulations are used to set specifications for target fabrication. Recent design work has focused on incorporating the implications of NIF experiments that were done in fall 2009 and planning for the campaign in 2010. Near-term experiments will use Ge-doped CH, although Be and diamond are still under active consideration for 2011 and beyond. The emphasis in this paper will be on changes in the requirements over the last year, the characteristics of the 2010 CH-ablator design, and the designs for 2011 and beyond. Capsule defects of particular interest are surface perturbations on the CH ablator and composition variations in the Be shells. Complete tables of specifications are regularly updated for all of the targets. All the specifications are rolled together into an error budget indicating adequate margin for ignition with all of the designs.

Ignition and inertial confinement fusion at the National Ignition Facility

The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and for studying high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). The NIF is now conducting experiments to commission the laser drive, the hohlraum and the capsule and to develop the infrastructure needed to begin the first ignition experiments in FY 2010. Demonstration of ignition and thermonuclear burn in the laboratory is a major NIF goal. NIF will achieve this by concentrating the energy from the 192 beams into a mm3-sized target and igniting a deuterium-tritium mix, liberating more energy than is required to initiate the fusion reaction. NIF's ignition program is a national effort managed via the National Ignition Campaign (NIC). The NIC has two major goals: execution of DT ignition experiments starting in FY2010 with the goal of demonstrating ignition and a reliable, repeatable ignition platform by the conclusion of the NIC at the end of FY2012. The NIC will also develop the infrastructure and the processes required to operate NIF as a national user facility. The achievement of ignition at NIF will demonstrate the scientific feasibility of ICF and focus worldwide attention on laser fusion as a viable energy option. A laser fusion-based energy concept that builds on NIF, known as LIFE (Laser Inertial Fusion Energy), is currently under development. LIFE is inherently safe and can provide a global carbon-free energy generation solution in the 21st century. This paper describes recent progress on NIF, NIC, and the LIFE concept.

Analyses of laser-plasma interactions in NIF ignition emulator designs

The National Ignition Campaign is currently conducting energetics experiments at the National Ignition Facility (NIF). These experiments directly test all aspects of ignition hohlraum performance. An important aspect of good performance is understanding and mitigation of laser-plasma interactions, which enables laser coupling to the target. The hohlraum energetics target and pulse-shape are designed to produce an ignition-hohlraum-like plasma to test laser-plasma interactions. The pre-shot laser-plasma interaction predictions for the first energetics targets (one room temperature target, and one cryogenic target) are presented here. These findings correlate well with the experimental data, namely that the primary concern is stimulated Raman scatter of the inner beams deep in the target. Such scatter is mostly re-absorbed, but modifies the energy deposition profile and thus the symmetry. Stimulated Brillouin scatter is at low levels, both in pre-shot predictions and in the experiments.

The National Ignition Facility and the National Ignition Campaign

The National Ignition Facility (NIF), the world's largest and most powerful laser system for inertial confinement fusion (ICF) and experiments studying high-energy-density (HED) science, is now operational at Lawrence Livermore National Laboratory (LLNL). NIF construction was certified by the Department of Energy as complete on March 27, 2009. NIF, a 192-beam Nd:glass laser facility, will ultimately produce 1.8 MJ 500 TW of 351-nm third-harmonic ultraviolet light. On March 10, 2009, a total of 192-beam energy of 1.1 MJ was demonstrated; this is approximately 30 times more energy than ever produced in an ICF laser system. The principal goal of NIF is to achieve ignition of a deuterium-tritium (DT) fuel capsule and provide access to HED physics regimes needed for experiments related to national security, fusion energy, and broader frontier scientific exploration. NIF experiments in support of indirect-drive ignition began in August 2009. These first experiments represent the next phase of the National Ignition Campaign (NIC). The NIC is a national effort to achieve fusion ignition and is coordinated through a detailed execution plan that includes science, technology, and equipment. The equipment required for ignition experiments includes diagnostics, a cryogenic target manipulator, and user optics. Participants in this effort include LLNL, General Atomics, Los Alamos National Laboratory, Sandia National Laboratory, and the University of Rochester Laboratory for Energetics. The primary goal for NIC is to have all of the equipment operational, integrated into the facility, and ready to begin a credible ignition campaign in 2010. With NIF now operational, the long-sought goal of achieving self-sustained nuclear fusion and energy gain in the laboratory is much closer to realization. Successful demonstration of ignition and net energy gain on NIF will be a major step toward demonstrating the feasibility of inertial fusion energy (IFE) and will likely focus the world's attention on the possibility of an ICF energy option. NIF experiments to demonstrate ignition and gain will use central-hot-spot (CHS) ignition, where a spherical fuel capsule is simultaneously compressed and ignited. The scientific basis for CHS has been intensively developed. Achieving ignition with CHS will open the door for other advanced concepts, such as the use of high-yield pulses of visible wavelength rather than ultraviolet and fast-ignition concepts. Moreover, NIF will have important scientific applications in such diverse fields as astrophysics, nuclear physics, and materials science. The NIC will develop the full set of capabilities required to operate NIF as a major national and international user facility. A solicitation for NIF frontier science experiments is planned for summer 2009. This paper summarizes the design, performance, and status of NIF and plans for the NIF ignition experimental program. A brief summary of the overall NIF experimental program is also presented.