On December 5th, 2022, controlled fusion ignition was demonstrated for the first time at the National Ignition Facility (NIF), a major achievement in the field of Inertial Confinement Fusion (ICF) requiring a multi-decadal effort involving broad national and international collaborations. To drive the fusion ignition reaction with the compressed fuel capsule, that yielded 3.15 MJ of nuclear energy [1], the NIF laser delivered a high-precision pulse shape with 2.05 MJ of ultra-violet (UV) laser energy and a peak power of 440 TW. This laser energy was an increase of similar to 8 % compared to that delivered on the previous "threshold of ignition" record yield experiment (1.37 MJ of yield for 1.89 MJ of laser energy) on August 8th, 2021 [2]. We explain how the results of our extensive research in laser technology and UV optics damage mitigation led to major improvements in the NIF laser, enabling this energy increase along with additional accuracy, precision, and power balance enhancements. Furthermore, we will discuss on-going efforts that have enabled operations at 2.2 MJ of UV energy as well as potential new initiatives to push the laser performance -accuracy and delivered energy- to even higher levels in the future as previously demonstrated on a small subset of NIF beams [3].

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Compound parabolic concentrator (CPC) targets are utilized at the National Ignition Facility Advanced Radiographic Capability (NIF-ARC) laser to enhance the acceleration of electrons and production of high energy photons, for laser durations of 10 ps and energies up to 2.4 kJ. A large enhancement of mean electron energy (>2 ×) and photon brightness (>10×) is found with CPC targets compared to flat targets. Using multiple diagnostic techniques at different spatial locations and scaling by gold activation spatial data, photon spectra are characterized for Ephoton=0.5–30 MeV. Beam width and pointing variations are given. The efficient production of MeV photons at Ilaser≈2×1018 W/cm2 with CPCs is observed, with doses of >10 rad in air at 1 m for Ephoton>0.5 MeV; these exceed those previously reported with laser-driven sources. Using this source, sub-mm resolution radiographs are generated through large areal density radiograph objects. These results are promising for the development of bright MeV x-ray and particle sources on Petawatt class laser systems.

Introduction The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory is the National Nuclear Security Administration (NNSA) Stockpile Stewardship Program’s (SSP) premier tool for High Energy Density (HED) Physics science, delivering data at levels of precision, pressure and temperature unparalleled in the world [1,2] and recently fusion experiments on the threshold of ignition [3]. With continued upgrades and plans for modest changes that would produce significant performance enhancements, the NIF will likely be the leading ICF facility for studying fusion ignition at full scale for at least another decade. Additionally, there are multiple areas of Inertial Fusion Energy (IFE) development where NIF can play an important role, ranging from testing of high gain advanced ignition schemes, to target chamber dynamics experiments, to materials damage, to Equation of State (EOS) studies of IFE-relevant materials (for target ablators or chamber walls) at extreme conditions, to data for the further development of code predictive capability. Furthermore, lessons from NIF in construction, operations, systems integration, and large facility architecture will provide a very useful steppingstone to any follow-on dedicated IFE facility.

Achieving a high conversion efficiency into relativistic electrons is central to short-pulse laser application and fundamentally relies on creating interaction regions with intensities ≫10^{18}W/cm^{2}. Small focal length optics are typically employed to achieve this goal; however, this solution is impractical for large kJ-class systems that are constrained by facility geometry, debris concerns, and component costs. We fielded target-mounted compound parabolic concentrators to overcome these limitations and achieved nearly an order-of-magnitude increase to the conversion efficiency and more than tripled electron temperature compared to flat targets. Particle-in-cell simulations demonstrate that plasma confinement within the cone and formation of turbulent laser fields that develop from cone wall reflections are responsible for the improved laser-to-target coupling. These passive target components can be used to improve the coupling efficiency for all high-intensity short-pulse laser applications, particularly at large facilities with long focal length optics.

The Precision Diagnostic System (PDS) is an advanced set of laser diagnostic tools installed within the National Ignition Facility (NIF). It is capable of picking off a single, full aperture, 1053nm (1 omega) beamline before the beam propagates to the target chamber and directing it to a suite of precision laser diagnostics. It was instrumental in validating the performance of the final optics 3 omega frequency conversion system design when NIF was built. The PDS has recently been recommissioned after more than a decade of non-use and enhanced to better understand laser performance limitations' and to characterize underperforming beams. In addition to recommissioning existing diagnostics for calorimetry, power, wavefront, near-field and far-field imaging, new diagnostics have been added: two types of time-resolved near field imaging systems; higher resolution wavefront imaging; and a 1 omega spectrometer. Additionally, the beam transport system was upgraded to allow PDS to select among four different 1 omega beamlines to enable improved understanding of beam-to-beam variations. Two of these four beams are top hemisphere beams, while two are bottom-hemisphere, with known performance variations. The results from NIF Shots with the new and recommissioned PDS diagnostic (spatial resolution, dynamic range, time gating, etc..) will be reviewed and data up to 14 kJ, 3.2 TW will be presented.

The implosion efficiency in inertial confinement fusion depends on the degree of stagnated fuel compression, density uniformity, sphericity, and minimum residual kinetic energy achieved. Compton scattering-mediated 50-200 keV x-ray radiographs of indirect-drive cryogenic implosions at the National Ignition Facility capture the dynamic evolution of the fuel as it goes through peak compression, revealing low-mode 3D nonuniformities and thicker fuel with lower peak density than simulated. By differencing two radiographs taken at different times during the same implosion, we also measure the residual kinetic energy not transferred to the hot spot and quantify its impact on the implosion performance.

The National Ignition Facility (NIF), located at Lawrence Livermore National Laboratory, is the world's largest and highest-energy laser system. NIF's 192 intense laser beams can deliver more energy than any previous laser system with a design point of 1.8 MJ of UV and 500 TW peak power. Efforts are currently underway to better understand the NIF performance and its limitations(1). One goal of recent and future campaigns is to better understand the accumulation of B-integral within the NIF laser using existing diagnostics, as well as the Precision Diagnostic System (PDS). Among these diagnostics, the Shack-Hartmann (SH) sensor in the Output Sensor Package (OSP), a standard NIF diagnostic, and the dedicated PDS Radial Shearing Interferometer (RSI) both measure the wavefront of the beam. Using these diagnostics in concert with the NIF Programmable Spatial Shaper (PSS), which is used to tailor arbitrary spatial beam profiles, we have performed integrated experiments to study the B-Integral induced wavefront through the entire NIF main laser. We propagated a probe beam with a slowly varying spatial intensity profile through the NIF laser to produce a spatially varying B-Integral induced wavefront at the laser output, from which we obtained the magnitude of the B-Integral of the system. We present these direct measurements of the spatially resolved B-Integral induced wavefront scaled for the first time from a table-top experiment(2) to a fusion-class laser chain These measurements are compared to results of current simulations using Virtual Beamline (VBL) software(3).

The National Ignition Facility (NIF) at Lawrence Livermore National Laboratory, is the first of its kind megajoule-class laser facility with 192 beams capable of delivering over 1.8 MJ and 500TW of 351 nm light for high accuracy laser-matter interaction experiments. It has been commissioned and operated since 2009 to support a wide range of missions including the study of inertial confinement fusion, high energy density physics, material science, and laboratory astrophysics. In the first section of this paper we discuss the current status of laser performance obtained during the 408 target experiments completed in 2017. The performance spanned a wide range of laser energies, powers and pulse durations as requested for these target experiments. A special emphasis is given on energy delivery and cone power accuracy in the UV, as these are key parameters for successful experiments. In the second section of the paper, the results obtained during the 2017 performance quad campaign are briefly described. During this campaign a series of laser-only shots were taken to perform tests at elevated energies on a single NIF quad. These tests were designed to assess laser performance limits and operational costs against predictive models. This campaign culminated with the delivery of similar to 54 kJ of UV on a single quad of NIF, and 14 kJ on a single beam aperture, which are both to our knowledge the largest energies achieved to date for a neodymium-glass, frequency tripled architecture.

The Cherenkov Telescope Array (CTA) will be the next generation ground-based observatory for gamma-ray astronomy at very-high energies. CTA will consist of two large arrays with 118 Cherenkov telescopes in total, deployed in the northern and southern hemispheres. The Observation Execution System (OES) provides the means to execute observations and to handle the acquisition of scientific data in CTA. The Manager and Central Control (MCC) system is a core element in the OES system that implements the execution of observation requests received from the scheduler sub-system. This contribution provides a summary of the main MCC design features and of the plans for prototyping.

Measured pointing jitter from NIF is used to simulate the effect of Max-of-N accumulated fluence distribution. The simulate result was able to reproduce the measured Max-of-N effect for different energy and wavelength operations.

The Cherenkov Telescope Array (CTA) is the next-generation atmospheric Cherenkov gamma-ray observatory. The Observation Execution System (OES) team within the CTA project is designing and prototyping the software to execute the observations and to handle the acquisition of scientific data at GB/s rates. In this contribution we show the OES system as it is being designed using the Unified Modeling Language (UML) and Systems Modeling (SysML) formalisms. In addition, we present the status of the associated prototyping activities.

We have demonstrated the world's highest average power, fully diode-pumped, petawatt-class peak power laser, the High-repetition-rate Advanced Petawatt Laser System (HAPLS) [1-3]. These first commissioning results at 16J (stretched) at 3%Hz fully validate projected performance of 30J/30fs (>1PW) at 10Hz. The laser has been operated at this intermediate level at Lawrence Livermore National Laboratory to demonstrate integrated performance of all subsystems and provide benchmarking data to laser performance models before further increasing energy and peak power. Data was obtained during multiple campaigns, exceeding several hours of run time, and a snapshot of 60min of data is shown in Fig. 1. The average pump laser 1ω (1053nm) energy was 97J with an rms stability of 0.7%, 2ω (527nm) energy at the Ti:sapphire power amplifier was 62J, and the average stretched short pulse energy was 16J. A full-aperture diagnostic suite allows simultaneous, single-shot measurement of energy, spectrum, beam quality, and pulse duration at full repetition rate. Single-shot SPIDER retrieved pulse shapes (Fig. 1 inset) with an average pulse duration over 12000 consecutive shots of 28.6fs (rms=1.4fs). The mean pulse duration is consistent with the measured spectral bandwidth and is ∼1.2× the transform limit. All results shown are raw data without filtering or averaging, demonstrating the exceptional pulse characteristics, repeatability, and stability of the entire laser system.

Large laser systems that deliver optical pulses with peak powers exceeding one Petawatt (PW) have been constructed at dozens of research facilities worldwide and have fostered research in High-Energy-Density (HED) Science, High-Field and nonlinear physics [1]. Furthermore, the high intensities exceeding 1018W/cm2 allow for efficiently driving secondary sources that inherit some of the properties of the laser pulse, e.g. pulse duration, spatial and/or divergence characteristics. In the intervening decades since that first PW laser, single-shot proof-of-principle experiments have been successful in demonstrating new high-intensity laser-matter interactions and subsequent secondary particle and photon sources. These secondary sources include generation and acceleration of charged-particle (electron, proton, ion) and neutron beams, and x-ray and gamma-ray sources, generation of radioisotopes for positron emission tomography (PET), targeted cancer therapy, medical imaging, and the transmutation of radioactive waste [2, 3]. Each of these promising applications requires lasers with peak power of hundreds of terawatt (TW) to petawatt (PW) and with average power of tens to hundreds of kW to achieve the required secondary source flux.

The HAPLS laser system has been commissioned to its first integrated performance milestone, delivering laser pulses with 16J sub-30fs duration at a 3⅓Hz repetition rate. This first all-diode-pumped petawatt-class laser offers the average powers required for secondary source applications.

The Advanced Radiographic Capability (ARC) laser system at the National Ignition Facility (NIF) is designed to ultimately provide eight beamlets with a pulse duration adjustable from 1 to 30 ps, and energies up to 1.5 kJ per beamlet. Currently, four beamlets have been commissioned. In the first set of 6 commissioning target experiments, the individual beamlets were fired onto gold foil targets with energy up to 1 kJ per beamlet at 20–30 ps pulse length. The x-ray energy distribution and pulse duration were measured, yielding energy conversion efficiencies of 4–9 × 10−4 for x-rays with energies greater than 70 keV. With greater than 3 J of such x-rays, ARC provides a high-precision x-ray backlighting capability for upcoming inertial confinement fusion and high-energy-density physics experiments on NIF.

The Cherenkov Telescope Array (CTA) project is an initiative to build two large arrays of Cherenkov gamma- ray telescopes. CTA will be deployed as two installations, one in the northern and the other in the southern hemisphere, containing dozens of telescopes of different sizes. CTA is a big step forward in the field of ground- based gamma-ray astronomy, not only because of the expected scientific return, but also due to the order-of- magnitude larger scale of the instrument to be controlled. The performance requirements associated with such a large and distributed astronomical installation require a thoughtful analysis to determine the best software solutions. The array control and data acquisition (ACTL) work-package within the CTA initiative will deliver the software to control and acquire the data from the CTA instrumentation. In this contribution we present the current status of the formal ACTL system decomposition into software building blocks and the relationships among them. The system is modelled via the Systems Modelling Language (SysML) formalism. To cope with the complexity of the system, this architecture model is sub-divided into different perspectives. The relationships with the stakeholders and external systems are used to create the first perspective, the context of the ACTL software system. Use cases are employed to describe the interaction of those external elements with the ACTL system and are traced to a hierarchy of functionalities (abstract system functions) describing the internal structure of the ACTL system. These functions are then traced to fully specified logical elements (software components), the deployment of which as technical elements, is also described. This modelling approach allows us to decompose the ACTL software in elements to be created and the ow of information within the system, providing us with a clear way to identify sub-system interdependencies. This architectural approach allows us to build the ACTL system model and trace requirements to deliverables (source code, documentation, etc.), and permits the implementation of a flexible use-case driven software development approach thanks to the traceability from use cases to the logical software elements. The Alma Common Software (ACS) container/component framework, used for the control of the Atacama Large Millimeter/submillimeter Array (ALMA) is the basis for the ACTL software and as such it is considered as an integral part of the software architecture.

We are studying the implementation of polar direct drive (PDD) ignition experiments on the National Ignition Facility (NIF) laser system. Part of this preparation involves testing the performance of the NIF laser system over a broader span of center wavelengths, 3.6 nm, where the laser currently operates and that gain models describe. The temporal shape for the PDD pulses consists of a drive pulse preceded by three lower power “picket pulses”. These picket pulses require a multi-FM sinusoidal phase modulation format with a bandwidth of ∼ 200 GHz and a more dispersive grating in the preamplifier module (PAM) for smoothing-by-spectral-dispersion (SSD). In this paper we discuss recent measurements of gain on the NIF laser system over this broader wavelength range. We measured FM-to-AM conversion over the 3.6 nm wavelength range. The possibility of pinhole closure due to the larger bandwidth and dispersion associated with multi-FM SSD was studied at LLE on the OMEGA EP laser.

The Cherenkov Telescope Array (CTA), as the next generation ground-based very high-energy gamma-ray observatory, is defining new areas beyond those related to physics. It is also creating new demands on the control and data acquisition system. CTA will consist of two installations, one in each hemisphere, containing tens of telescopes of different sizes. The ACTL (array control and data acquisition) system will consist of the hardware and software that is necessary to control and monitor the CTA array, as well as to time-stamp, read-out, filter and store the scientific data at aggregated rates of a few GB/s. The ACTL system must implement a flexible software architecture to permit the simultaneous automatic operation of multiple sub-arrays of telescopes with a minimum personnel effort on site. In addition ACTL must be able to modify the observation schedule on timescales of a few tens of seconds, to account for changing environmental conditions or to prioritize incoming scientific alerts from time-critical transient phenomena such as gamma-ray bursts. This contribution summarizes the status of the development of the software architecture and the main design choices and plans.

Complex and precise research targets are required for the inertial confinement fusion (ICF) experiments conducted at the National Ignition Facility. During the National Ignition Campaign (NIC) the target development team embarked on and completed a science and technology campaign to provide the capability to produce the required targets at the rate needed by the NIC. An engineering design for precision, manufacturing, and fielding was developed. This required new processes, new tooling, and equipment to metrologize and assemble components. In addition, development of new processing technology was also required.Since the NIC had to respond to new results from ICF experiments, the target development team had to respond as well. This required target designs that allowed for flexibility in accommodating changes in the targets for capsule dimensions and doping levels, hohlraztm dimensions and materials, and various new platforms to investigate new physics. A continuous improvement of processes was also required to meet stringent specifications and fielding requirements.