Relative sensitivity of plastic scintillator: A comparative analysis with 60Co gamma rays, deuterium-deuterium, and deuterium-tritium neutrons.

A plastic scintillator has found extensive application in the realm of high-energy physics and national security science. Many applications in those fields often involve the simultaneous production of photons, neutrons, and charged particles, which makes the relative sensitivity information for these different radiation types important. In this study, we have adopted a multi-head detector comprised of a plastic scintillator and high gain phototubes, which provides a large dynamic range and linearity.

Reduced-order model to approximate response matrices for filter stack spectrometers.

We present a reduced-order model to calculate response matrices rapidly for filter stack spectrometers (FSSs). The reduced-order model allows response matrices to be built modularly from a set of pre-computed photon and electron transport and scattering calculations through various filter and detector materials. While these modular response matrices are not appropriate for high-fidelity analysis of experimental data, they encode sufficient physics to be used as a forward model in design optimization studies of FSSs, particularly for machine learning approaches that require sampling and testing a large number of FSS designs.

Machine learning based unfolding of x-ray spectra from filter stack spectrometer data.

We demonstrate the application of neural networks to perform x-ray spectra unfolding from data collected by filter stack spectrometers. A filter stack spectrometer consists of a series of filter-detector pairs, where the detectors behind each filter measure the energy deposition through each layer as photo-stimulated luminescence (PSL). The network is trained on synthetic data, assuming x-rays of energies <1 MeV and of two different distribution functions (Maxwellian and Gaussian) and the corresponding measured PSL values obtained from five different filter stack spectrometer designs.

A modular, high dynamic range passive neutron dosimeter and imaging diagnostic.

The multi-decade neutron dosimeter and imaging diagnostic (MDND) is a passive diagnostic that utilizes the polyethylene (n, p) nuclear reaction to enhance the diagnostic's sensitivity for time and energy integrated neutron measurements in the range of 2.45-14.1 MeV.

Robust unfolding of MeV x-ray spectra from filter stack spectrometer data.

We present an inversion method capable of robustly unfolding MeV x-ray spectra from filter stack spectrometer (FSS) data without requiring an a priori specification of a spectral shape or arbitrary termination of the algorithm. Our inversion method is based upon the perturbative minimization (PM) algorithm, which has previously been shown to be capable of unfolding x-ray transmission data, albeit for a limited regime in which the x-ray mass attenuation coefficient of the filter material increases monotonically with x-ray energy. Our inversion method improves upon the PM algorithm through regular smoothing of the candidate spectrum and by adding stochasticity to the search.

National Diagnostic Working Group (NDWG) for inertial confinement fusion (ICF)/high-energy density (HED) science: The whole exceeds the sum of its parts.

The National Diagnostic Working Group (NDWG) has led the effort to fully exploit the major inertial confinement fusion/high-energy density facilities in the US with the best available diagnostics. These diagnostics provide key data used to falsify early theories for ignition and suggest new theories, recently leading to an experiment that exceeds the Lawson condition required for ignition. The factors contributing to the success of the NDWG, collaboration and scope evolution, and the methods of accomplishment of the NDWG are discussed in this Review.

Day after rescue ICSI: eliminating total fertilization failure after conventional IVF with high live birth rates following cryopreserved blastocyst transfer.

Study Question: What is the impact of day after rescue ICSI (r-ICSI) on success of fresh and frozen embryo transfers?

Summary Answer: The use of r-ICSI can virtually allay fears of total fertilization failure (TFF) after conventional IVF (C-IVF) and achieve high live birth rates after frozen blastocyst transfer.

What Is Known Already: More infertility clinics have resorted to the use of ICSI in place of C-IVF in IVF treatment owing to fear of TFF or a low fertilization rate. r-ICSI has been attempted either on the day of IVF or the day after.

Machine learning for detection of 3D features using sparse x-ray tomographic reconstruction.

In many inertial confinement fusion (ICF) experiments, the neutron yield and other parameters cannot be completely accounted for with one and two dimensional models. This discrepancy suggests that there are three dimensional effects that may be significant. Sources of these effects include defects in the shells and defects in shell interfaces, the fill tube of the capsule, and the joint feature in double shell targets.

Three-dimensional reconstruction of neutron, gamma-ray, and x-ray sources using a cylindrical-harmonics expansion.

Inertial confinement fusion capsule implosions produce neutron, gamma-ray, and x-ray emission, which are recorded by a variety of detectors, both time integrated and time resolved, to determine the performance of the implosion. Two-dimensional emission images from multiple directions can now be combined to infer three-dimensional structures in the implosion, such as the distribution of thermonuclear fuel density, carbon ablator, and impurities. Because of the cost and complexity of the imaging systems, however, only a few measurements can be made, so reconstructions of the source must be made from a limited number of views.

Demonstration of Scale-Invariant Rayleigh-Taylor Instability Growth in Laser-Driven Cylindrical Implosion Experiments.

Rayleigh-Taylor instability growth is shown to be hydrodynamically scale invariant in convergent cylindrical implosions for targets that varied in radial dimension and implosion timescale by a factor of 3. The targets were driven directly by laser irradiation providing a short impulse, and instability growth at an embedded aluminum interface occurs as it converges radially inward by a factor of 2.25 and decelerates on a central foam core.

Optimizing neutron imaging line of sight locations for maximizing sampling of the cold fuel density in inertial confinement fusion implosions at the National Ignition Facility.

Neutron imaging provides a ready measurement of the shape of the "hot spot" core of an inertial confinement fusion implosion. The 14-MeV neutrons emitted by deuterium-tritium reactions are imaged at the National Ignition Facility using a pinhole array onto a scintillator, and the images are recorded on a camera. By changing the gate time of the camera, lower energy neutrons, downscattered by the cold fuel surrounding the hot spot, are recorded.

Progress on next generation gamma-ray Cherenkov detectors for the National Ignition Facility.

Fusion reaction history and ablator areal density measurements for Inertial Confinement Fusion experiments at the National Ignition Facility are currently conducted using the Gamma Reaction History diagnostic (GRH_6m). Future Gas Cherenkov Detectors (GCDs) will ultimately provide ∼100x more sensitivity, reduce the effective temporal response from ∼100 to ∼10 ps, and lower the energy threshold from 2.9 to 1.

Effects of asymmetry and hot-spot shape on ignition capsules.

Asymmetric implosion of inertial confinement fusion capsules is known, both experimentally and computationally, to reduce thermonuclear performance. This work shows that low-mode asymmetries degrade performance as a result of a decrease in the hydrodynamic disassembly time of the hot-spot core, which scales with the minimum dimension of the hot spot. The asymmetric shape of a hot spot results in decreased temperatures and areal densities and allows more alpha particles to escape, relative to an ideal spherical implosion, thus reducing alpha-energy deposition in the hot spot.

Inorganic Phosphate and Arsenate within New Tetranuclear Copper and Zinc Complexes: Syntheses, Crystal Structures, Magnetic, Electrochemical, and Thermal Studies.

Three, PO /HPO and AsO -incorporated, new tetranuclear complexes of copper(II) and zinc(II) ions have been synthesized and fully characterized. In methanol-water, reactions of Hcpdp (Hcpdp = ,'-Bis[2-carboxybenzomethyl]-,'-Bis[2-pyridylmethyl]-1,3-diaminopropan-2-ol) with copper(II) chloride in the presence of either NaOH/NaHPO·2HO or KOH/NaHAsO·7HO lead to the isolation of the tetranuclear complexes Na[Cu(cpdp)(μ-PO)](OH)·14HO () and K[Cu(cpdp)(μ-AsO)](OH)·16/HO (), respectively. Similarly, the reaction of Hcpdp with zinc(II) chloride in the presence of NaOH/NaHPO·2HO yields a tetranuclear complex, Na(HO)[Zn(cpdp)(μ-HPO)]Cl·12/HO ().

First Liquid Layer Inertial Confinement Fusion Implosions at the National Ignition Facility.

The first cryogenic deuterium and deuterium-tritium liquid layer implosions at the National Ignition Facility (NIF) demonstrate D_{2} and DT layer inertial confinement fusion (ICF) implosions that can access a low-to-moderate hot-spot convergence ratio (1230) DT ice layer implosions. Although high CR is desirable in an idealized 1D sense, it amplifies the deleterious effects of asymmetries.

Next generation gamma-ray Cherenkov detectors for the National Ignition Facility.

The newest generation of Gas Cherenkov Detector (GCD-3) employed in Inertial Confinement Fusion experiments at the Omega Laser Facility has provided improved performance over previous generations. Comparison of reaction histories measured using two different deuterium-tritium fusion products, namely gamma rays using GCD and neutrons using Neutron Temporal Diagnostic (NTD), have provided added credibility to both techniques. GCD-3 is now being brought to the National Ignition Facility (NIF) to supplement the existing Gamma Reaction History (GRH-6m) located 6 m from target chamber center (TCC).

Case reports to suggest an algorithm for management of total fertilisation failure prior to use of donor gametes.

Purpose: Total fertilisation failure (TFF), even with intracytoplasmic sperm injection (ICSI), occurs in approximately 3 % of cycles, can be recurrent and the exact cause is difficult to elucidate. Differentiation between oocyte and sperm-related cause of TFF is possible using mouse oocyte-activation techniques, but is not an option within most clinical settings. Therefore, the management of these couples is clinically driven, and the endpoint, if recurrent, is often the use of donor gametes.

Extended performance gas Cherenkov detector for gamma-ray detection in high-energy density experiments.

A new Gas Cherenkov Detector (GCD) with low-energy threshold and high sensitivity, currently known as Super GCD (or GCD-3 at OMEGA), is being developed for use at the OMEGA Laser Facility and the National Ignition Facility (NIF). Super GCD is designed to be pressurized to ≤400 psi (absolute) and uses all metal seals to allow the use of fluorinated gases inside the target chamber. This will allow the gamma energy threshold to be run as low at 1.

Conceptual design of the gamma-to-electron magnetic spectrometer for the National Ignition Facility.

The Gamma-to-Electron Magnetic Spectrometer (GEMS) diagnostic is designed to measure the prompt γ-ray energy spectrum during high yield deuterium-tritium (DT) implosions at the National Ignition Facility (NIF). The prompt γ-ray spectrum will provide "burn-averaged" observables, including total DT fusion yield, total areal density (ρR), ablator ρR, and fuel ρR. These burn-averaged observables are unique because they are essentially averaged over 4π, providing a global reference for the line-of-sight-specific measurements typical of x-ray and neutron diagnostics.

Scaling laws for ignition at the National Ignition Facility from first principles.

We have developed an analytical physics model from fundamental physics principles and used the reduced one-dimensional model to derive a thermonuclear ignition criterion and implosion energy scaling laws applicable to inertial confinement fusion capsules. The scaling laws relate the fuel pressure and the minimum implosion energy required for ignition to the peak implosion velocity and the equation of state of the pusher and the hot fuel. When a specific low-entropy adiabat path is used for the cold fuel, our scaling laws recover the ignition threshold factor dependence on the implosion velocity, but when a high-entropy adiabat path is chosen, the model agrees with recent measurements.

Assembly of high-areal-density deuterium-tritium fuel from indirectly driven cryogenic implosions.

The National Ignition Facility has been used to compress deuterium-tritium to an average areal density of ~1.0±0.1 g cm(-2), which is 67% of the ignition requirement.