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.

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. As recently reported, a burning plasma state, where the alpha-heating in the plasma is the primary source of heating, was achieved in laboratory experiments. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin ``burn propagation'' into surrounding cold fuel, enabling the possibility of high energy gain. While ``scientific breakeven'' (i.e. unity target gain) has not yet been achieved, this talk reports the first controlled fusion experiment on the National Ignition Facility to produce capsule gain greater than unity (here 5.8) and reach ignition by many different formulations of the Lawson criterion. In the talk, we will discuss some key basic physics inertial confinement fusion (ICF) principles behind the burning plasma and ignition results as well as discuss future challenges.

In people with type 2 diabetes (T2D), the presence of microvascular disease is associated with increased risk for macrovascular events [(1)][1]. Of particular interest is whether microvascular disease is a risk factor for heart failure (HF) or has a role in its pathophysiology [(2)][2]. The

The National Ignition Facility (NIF) is a high-energy-density-physics, experimental user facility that focuses up to 1.8 MJ of UV light in 192 laser beams onto a mm-sized target at the center of a target chamber. This paper describes how we conduct experimental shots on the NIF. We review processes and tools used to facilitate experiment planning and operations. Safety and radiological aspects of NIF’s operations are discussed. We also describe efforts to continuously improve operational efficiency and further increase shot rate.

The first inertial confinement fusion implosion experiments with equimolar deuterium-tritium thermonuclear fuel have been performed on the National Ignition Facility. These experiments use 0.17 mg of fuel with the potential for ignition and significant fusion yield conditions. The thermonuclear fuel has been fielded as a cryogenic layer on the inside of a spherical plastic capsule that is mounted in the center of a cylindrical gold hohlraum. Heating the hohlraum with 192 laser beams for a total laser energy of 1.6 MJ produces a soft x-ray field with 300 eV temperature. The ablation pressure produced by the radiation field compresses the initially 2.2-mm diameter capsule by a factor of 30 to a spherical dense fuel shell that surrounds a central hot-spot plasma of 50 μm diameter. While an extensive set of x-ray and neutron diagnostics has been applied to characterize hot spot formation from the x-ray emission and 14.1 MeV deuterium-tritium primary fusion neutrons, thermonuclear fuel assembly is studied by measuring the down-scattered neutrons with energies in the range of 10 to 12 MeV. X-ray and neutron imaging of the compressed core and fuel indicate a fuel thickness of (14 ± 3) μm, which combined with magnetic recoil spectrometer measurements of the fuel areal density of (1 ± 0.09) g cm–2 result in fuel densities approaching 600 g cm–3. The fuel surrounds a hot-spot plasma with average ion temperatures of (3.5 ± 0.1) keV that is measured with neutron time of flight spectra. The hot-spot plasma produces a total fusion neutron yield of 1015 that is measured with the magnetic recoil spectrometer and nuclear activation diagnostics that indicate a 14.1 MeV yield of (7.5±0.1)×1014 which is 70% to 75% of the total fusion yield due to the high areal density. Gamma ray measurements provide the duration of nuclear activity of (170 ± 30) ps. These indirect-drive implosions result in the highest areal densities and neutron yields achieved on laser facilities to date. This achievement is the result of the first hohlraum and capsule tuning experiments where the stagnation pressures have been systematically increased by more than a factor of 10 by fielding low-entropy implosions through the control of radiation symmetry, small hot electron production, and proper shock timing. The stagnation pressure is above 100 Gbars resulting in high Lawson-type confinement parameters of Pτ≃10 atm s. Comparisons with radiation-hydrodynamic simulations indicate that the pressure is within a factor of three required for reaching ignition and high yield. This will be the focus of future higher-velocity implosions that will employ additional optimizations of hohlraum, capsule and laser pulse shape conditions.

Vascular access care accounts for a third of ESRD cost and is a leading cause of morbidity in hemodialysis (HD) patients. We designed this study to identify the risk factors for vascular access infection and to determine the cost of related hospitalizations. Methods: All HD patients at DCI Oakland from 1/1/99 to 6/30/02 were prospectively studied for access type, infections (Infx) including bacteremia, exit site, tunnel or cellulitis, and related hospitalizations. Cost data was obtained from the inpatient electronic medical record system. Risk factors for infection were evaluated using Poisson regression analysis, and cost comparison was done using ANOVA. Results: 153 patients were included in the analysis and were grouped by type of access: temporary catheter (TC) n = 84, permanent/tunneled catheter (PC) n = 158, AV graft (AVG) n = 87 and AV fistula (AVF) n = 57. Univariate analysis revealed significant risk factors to be female gender (p = 0.004, RR = 1.85) and type of access. In multivariate analysis, compared to AVF, risk of infection was highest with TC (p < 0.001, RR = 44), followed by PC (p < 0.001, RR = 17) and AVG (p = 0.03, RR = 3). Age, gender, and diabetes were not predictors of infection. The cost per hospitalization in the PC vs. AVG groups was not significantly different. Access type TC PC AVG AVF # Infx/1000 access days 5.0 3.8 0.6 0.1 % Infx requiring hospitalization 12.5 12.2 58.0 60.0 Cost/hosp. admission (mean) $16,896 25,683 9,016 5,650 Conclusions: Catheters are associated with much higher vascular access infection rates when compared to fistulas and grafts. When AVFs or AVGs do become infected, they are more likely to require hospitalization. Infections severe enough to require hospitalization result in similar inpatient cost per admission regardless of access type; however, this may be due to small sample size.

This paper introduces a unique thermal management architecture that employs vapor-compression refrigeration to cool, above the dew point, multiple independently operating microprocessors in a small volume. The refrigeration system is driven by a novel acoustic compressor technology that has the virtues of, among other things, being highly variable, oil-less, and orientation independent, and thus able to operate under significant variations in loading and deployment. The paper will also, therefore, introduce acoustic compression and discuss its application to the thermal management of electronics. A prototype 5U server with four 100 W, independently variable, heat loads demonstrating the technology has been built and experimental results are reviewed.

A method of producing a soft, comfortable, lightweight immediate obturator is described. This can be changed in an out-patient environment.