Observations and properties of the first laboratory fusion experiment to exceed a target gain of unity.

An indirect-drive inertial fusion experiment on the National Ignition Facility was driven using 2.05 MJ of laser light at a wavelength of 351 nm and produced 3.1±0.16 MJ of total fusion yield, producing a target gain G=1.5±0.1 exceeding unity for the first time in a laboratory experiment [Phys. Rev. E 109, 025204 (2024)10.1103/PhysRevE.109.025204]. Herein we describe the experimental evidence for the increased drive on the capsule using additional laser energy and control over known degradation mechanisms, which are critical to achieving high performance. Improved fuel compression relative to previous megajoule-yield experiments is observed. Novel signatures of the ignition and burn propagation to high yield can now be studied in the laboratory for the first time.

Neutron time of flight (nToF) detectors for inertial fusion experiments.

Neutrons generated in Inertial Confinement Fusion (ICF) experiments provide valuable information to interpret the conditions reached in the plasma. The neutron time-of-flight (nToF) technique is well suited for measuring the neutron energy spectrum due to the short time (100 ps) over which neutrons are typically emitted in ICF experiments. By locating detectors 10s of meters from the source, the neutron energy spectrum can be measured to high precision. We present a contextual review of the current state of the art in nToF detectors at ICF facilities in the United States, outlining the physics that can be measured, the detector technologies currently deployed and analysis techniques used.

Design of a multi-detector, single line-of-sight, time-of-flight system to measure time-resolved neutron energy spectra.

In the dynamic environment of burning, thermonuclear deuterium-tritium plasmas, diagnosing the time-resolved neutron energy spectrum is of critical importance. Strategies exist for this diagnosis in magnetic confinement fusion plasmas, which presently have a lifetime of ∼1012 longer than inertial confinement fusion (ICF) plasmas. Here, we present a novel concept for a simple, precise, and scale-able diagnostic to measure time-resolved neutron spectra in ICF plasmas. The concept leverages general tomographic reconstruction techniques adapted to time-of-flight parameter space, and then employs an updated Monte Carlo algorithm and National Ignition Facility-relevant constraints to reconstruct the time-evolving neutron energy spectrum. Reconstructed spectra of the primary 14.028 MeV nDT peak are in good agreement with the exact synthetic spectra. The technique is also used to reconstruct the time-evolving downscattered spectrum, although the present implementation shows significantly more error.

Constraining time-dependent ion temperature measurements in inertial confinement fusion (ICF) implosions with an intermediate distance neutron time-of-flight (nToF) detector.

A concept for using an intermediate distance (0.3-3.0 m) neutron time-of-flight (nToF) to provide a constraint on the measurement of the time-dependence of ion temperature in inertial confinement fusion implosions is presented. Simulated nToF signals at different distances are generated and, with a priori knowledge of the burn-averaged quantities and burn history, analyzed to determine requirements for a future detector. Results indicate a signal-to-noise ratio >50 and time resolution <20 ps to constrain the ion temperature gradient to ∼±25% (0.5 keV/100 ps).

Experimental achievement and signatures of ignition at the National Ignition Facility.

An inertial fusion implosion on the National Ignition Facility, conducted on August 8, 2021 (N210808), recently produced more than a megajoule of fusion yield and passed Lawson's criterion for ignition [Phys. Rev. Lett. 129, 075001 (2022)10.1103/PhysRevLett.129.075001]. We describe the experimental improvements that enabled N210808 and present the first experimental measurements from an igniting plasma in the laboratory. Ignition metrics like the product of hot-spot energy and pressure squared, in the absence of self-heating, increased by ∼35%, leading to record values and an enhancement from previous experiments in the hot-spot energy (∼3×), pressure (∼2×), and mass (∼2×). These results are consistent with self-heating dominating other power balance terms. The burn rate increases by an order of magnitude after peak compression, and the hot-spot conditions show clear evidence for burn propagation into the dense fuel surrounding the hot spot. These novel dynamics and thermodynamic properties have never been observed on prior inertial fusion experiments.

Design of an inertial fusion experiment exceeding the Lawson criterion for ignition.

We present the design of the first igniting fusion plasma in the laboratory by Lawson's criterion that produced 1.37 MJ of fusion energy, Hybrid-E experiment N210808 (August 8, 2021) [Phys. Rev. Lett. 129, 075001 (2022)10.1103/PhysRevLett.129.075001]. This design uses the indirect drive inertial confinement fusion approach to heat and compress a central "hot spot" of deuterium-tritium (DT) fuel using a surrounding dense DT fuel piston. Ignition occurs when the heating from absorption of α particles created in the fusion process overcomes the loss mechanisms in the system for a duration of time. This letter describes key design changes which enabled a ∼3-6× increase in an ignition figure of merit (generalized Lawson criterion) [Phys. Plasmas 28, 022704 (2021)1070-664X10.1063/5.0035583, Phys. Plasmas 25, 122704 (2018)1070-664X10.1063/1.5049595]) and an eightfold increase in fusion energy output compared to predecessor experiments. We present simulations of the hot-spot conditions for experiment N210808 that show fundamentally different behavior compared to predecessor experiments and simulated metrics that are consistent with N210808 reaching for the first time in the laboratory "ignition."

Understanding the effects of neutron scattering for neutron-yield-isotropy measurements at the NIF.

Neutron-yield diagnostics at the NIF have been upgraded to include 48 detectors placed around the NIF target chamber to assess the DT-neutron-yield isotropy for inertial confinement fusion experiments. Real-time neutron-activation detectors are used to understand yield asymmetries due to Doppler shifts in the neutron energy attributed to hotspot motion, variations in the fuel and ablator areal densities, and other physics effects. In order to isolate target physics effects, we must understand the contribution due to neutron scattering associated with the different hardware configurations used for each experiment. We present results from several calibration experiments that demonstrate the ability to achieve our goal of 1% or better precision in determining the yield isotropy.

Three-dimensional diagnostics and measurements of inertial confinement fusion plasmas.

Recent inertial confinement fusion measurements have highlighted the importance of 3D asymmetry effects on implosion performance. One prominent example is the bulk drift velocity of the deuterium-tritium plasma undergoing fusion ("hotspot"), vHS. Upgrades to the National Ignition Facility neutron time-of-flight diagnostics now provide vHS to better than 1 part in 104 and enable cross correlations with other measurements. This work presents the impact of vHS on the neutron yield, downscatter ratio, apparent ion temperature, electron temperature, and 2D x-ray emission. The necessary improvements to diagnostic suites to take these measurements are also detailed. The benefits of using cross-diagnostic analysis to test hotspot models and theory are discussed, and cross-shot trends are shown.

Interpolating individual line-of-sight neutron spectrometer measurements onto the "sky" at the National Ignition Facility (NIF).

Nuclear diagnostics provide measurements of inertial confinement fusion implosions used as metrics of performance for the shot. The interpretation of these measurements for shots with low mode asymmetries requires a way of combining the data to produce a "sky map" where the individual line-of-sight values are used to interpolate to other positions in the sky. These interpolations can provide information regarding the orientation of the low mode asymmetries. We describe the interpolation method, associated uncertainties, and correlations between different metrics, e.g., Tion, down scatter ratio, and hot-spot velocity direction. This work is also related to recently reported studies [H. G. Rinderknecht et al., Phys. Rev. Lett. 124, 145002 (2020) and K. M. Woo et al., Phys. Plasmas 27, 062702 (2020)] of low mode asymmetries. We report an analysis that makes use of a newly commissioned line of sight, a scheme for incorporating multiple neutron spectrum measurement types, and recent work on the sources of implosion asymmetry to provide a more complete picture of implosion performance.

Optimal choice of multiple line-of-sight measurements determining plasma hotspot velocity at the National Ignition Facility.

The measurement of plasma hotspot velocity provides an important diagnostic of implosion performance for inertial confinement fusion experiments at the National Ignition Facility. The shift of the fusion product neutron mean kinetic energy as measured along multiple line-of-sight time-of-flight spectrometers provides velocity vector components from which the hotspot velocity is inferred. Multiple measurements improve the hotspot velocity inference; however, practical considerations of available space, operational overhead, and instrumentation costs limit the number of possible line-of-sight measurements. We propose a solution to this classical "experiment design" problem that optimizes the precision of the velocity inference for a limited number of measurements.

Some principles and practices of genetic biobanking studies.

Genetic biobanking studies are becoming increasingly common as researchers recognise the need for large samples to identify the genetic basis of susceptibility to complex disease. In the present review, the authors give a brief overview of some of the issues that should be considered when implementing such a large-scale project, from study design to sample management, data coding and storage to the statistical analysis and engagement with the public. Specific solutions to these issues are presented, as implemented in the Generation Scotland projects, but the general principles outlined are relevant to any biobanking study.

Reflective multilayer optic as hard X-ray diagnostic on laser-plasma experiment.

A multilayer-based optic was tested for use as an X-ray diagnostic on a laser-plasma experiment. The multilayer optic was employed to selectively pass X-rays between 55 and 100 keV. An order of magnitude improvement in signal-to-noise ratio is achieved compared to a transmission crystal spectrometer. A multilayer response model, taking into account the source size and spectral content, is constructed and the outlook for application above 500 keV is briefly discussed. LLNL-JRNL-664311.

Tissue-specific subunit of the mouse cytosolic chaperonin-containing TCP-1.

We have cloned a novel Tcp-1-related mouse testis cDNA encoding a polypeptide of 531 amino acids which shares 81.2% identity with the zeta subunit of the mouse cytosolic chaperonin-containing TCP-1 (CCT). Immunoblot analysis of mouse testis CCT subunits separated by 2-dimensional gel electrophoresis indicates that this novel gene, Cctz-2, encodes a CCT subunit of Mr 57 000 and pI 7.1. Cctz-2 mRNA is detected only in testis whereas the other Cctz gene, Cctz-1, is expressed in all tissues investigated. The CCTzeta-2 subunit may have specific functions in the folding of testicular proteins and for interactions with testicular molecular chaperones.

Lead poisoning in common loons (Gavia immer).

Two emaciated common loons (Gavia immer) were believed to have died of lead poisoning when fragments of fishing lines and lead sinkers were discovered in their stomachs. Later a third emaciated loon, which had only the remnants of fishing line in its stomach, was suspected of being a possible lead-poisoning victim when all other test results were negative. The liver lead levels in the first two loons were 20.6 ppm and 46.1 ppm (wet weight), and the level in the third was 38.52 ppm (wet weight). Thirteen common loons dying of other causes had liver lead levels of less than 1 ppm (wet weight).

Characterization of an avian cholera epizootic in wild birds in western Nebraska.

Avian cholera killed an estimated 2500 birds in western Nebraska and eastern Wyoming from 28 November 1985 to late January 1986. Wild mallards (Anas platyrhynchos) suffered the most losses. Other wild waterfowl, wild turkeys (Meleagris gallopavo), a few domestic fowl, and a bald eagle (Haliaeetus leucocephalus) also died. Pasteurella multocida serotype 1 was the predominant isolate from these carcasses. Cold, wet weather persisted throughout the outbreak, but daily losses in the flock of 50,000 mallards using the area were low. Pasteurella multocida was isolated from nasal swabs of 35 of 37 cattle from a feedlot in which many of these mallards were feeding. Eighty percent of the cattle isolates had antigenic characteristics of serotype 3 or serotype 3 with cross-reactivity. Isolates from wild mallards, wild turkeys, and the bald eagle were virulent to game-farm mallards when inoculated subcutaneously, but P. multocida isolates from cattle were not.

Epizootic of coccidiosis in free-flying lesser scaup.

A coccidiosis epizootic has occurred in lesser scaup (Aythya affinis) at Bluestem Reservoir in eastern Nebraska during the spring in each of three recent years: 1976-1978. Losses peaked during the period from mid-March through April. As much as 29% of the peak population of scaup using the reservoir died. Necropsies of 72 of the nearly 1390 scaup that died revealed destruction and sloughing of the intestinal mucosa and associated hemorrhaging. Fibrinonecrotic cores were frequently found in the intestinal lumens. Scrapings from the intestinal mucosal contained massive numbers of oocysts of the coccidian Eimeria aythyae. This is the first report of recurrent epizootics of coccidiosis in freeflying waterfowl.

Disclosure of disability: exploring the perspective of parents.

OBJECTIVE: To explore the perspective of parents with regard to disclosure of disability and early follow-up care. DESIGN: The research approach was hermeneutic phenomenology. Data were collected using focused interviews that were audio-taped, transcribed and interpreted. SETTING: Scotland. PARTICIPANTS: The parents of 63 children born with a congenital limb deficiency. FINDINGS: The findings demonstrate the complexity and variability in parental response. Additionally, what is shown is that disclosure was often handled poorly and that the support offered during the stay in the maternity unit was frequently inadequate. CONCLUSION: In order to handle disclosure effectively, health professionals require appropriate education and training and it is recommended that innovative ways of encouraging discussion and debate are sought.

Endothelial dysfunction associated with obesity and the effect of weight loss interventions.

Endothelial damage is central to the initiation and progression of atherosclerosis, while in addition vascular endothelial cells secrete several anti-atherogenic substances including the potent vasodilator nitric oxide. Increased adhesion molecule expression, in response to pathophysiological stimuli is perhaps the earliest indicator of compromised endothelial integrity. Obesity and adiposity are associated with an increased risk of CVD, influencing disease progression via a number of mechanisms, including enhanced endothelial activation. This review discusses possible mechanisms linking adiposity and more specifically regional fat depots with endothelial function and evaluates studies investigating the effect of weight loss on endothelial function, assessed by biochemical and physiological measurements. Overall, the research to date suggests that visceral adiposity is a stronger predictor of endothelial activation than overall adiposity, possibly mediated via the action of NEFA in circulation. While in general there is a suggestion that weight loss is associated with significant improvements in endothelial function, this is not apparent in all interventions and published literature to date provides less than convincing evidence for the effects of weight loss on endothelial activation.

Large hydatidiform mole: an unusual finding in a calving cow.

CASE HISTORY: A 4-year-old Friesian cow was reported to be having difficulty calving. Palpation by farm staff identified a large mass in the uterus, but no calf. CLINICAL FINDINGS: Veterinary examination per vaginam identified a small calf and a large immobile mass. The calf was delivered by Caesarean section, but the mass could not be extracted during surgery. Biopsying the mass resulted in the loss of a large amount of fluid from it, but it remained immovable; overnight, the mass was expelled per vaginam. Gross and histological examination of the mass showed it to comprise multiple oedematous chorionic villi, prominent stratified trophoblast, undifferentiated sub-trophoblastic mesenchymal tissue that contained adipose tissue, blood vessels and bizarre striated muscle fibres, as well as irregular cisterns in the centre. No recognisable embryonic or fetal tissue was found. DIAGNOSIS: Based on the gross and histological appearance it was concluded the mass was a complete hydatidiform mole. CLINICAL RELEVANCE: This is a rare, poorly understood condition of cattle. This is believed to be the first report in a cow in New Zealand.