Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “double”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,009 records · Page 56

A Double Sided LGAD-Based Detector Providing Timing, Position, and Track Angle Information

We describe a detector concept which combines small pixels enabled by 3D sensor-electronics integration with gain produced by a Low Gain Avalanche Diode (LGAD) layer. The detector is double-sided, with electrons collected by the cathode, which provides timing information, and an anode with small pixels to provide position and angle information. The cathode can be coarse grained, providing timing with fewer fast amplifiers to limit power consumption. The anode layer benefits from the gain of the LGAD, with larger signals that also limit the power needed. Position can be reconstructed by measuring the pattern of total charge deposited on the anode. Angle and depth of charge deposit can be measured by the shapes of the anode pulses. We describe a possible assembly technology based on 3D integration.

3D Integration↗

Hanford Double Shell Waste Tank Corrosion Studies (Final Report FY2021)

For fiscal year (FY) 2021, the Savannah River National Laboratory (SRNL) focused on two experimental tasks related to Hanford Double Shell Tank (DST) chemistry and integrity. The first task focused on understanding risk of corrosion due to formation of either continuous layers or discrete patches of deposits on the tanks’ inner sidewalls and bottoms. The second task studied vapor space corrosion (VSC) inhibition of the secondary liner using vapor corrosion inhibitors (VCIs) at dosages less than the manufacturer recommended and a control test in which no VCIs were added.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Preshot Report for OMEGA Double Cylinders (CylDRT 22B)

The primary goals for the May 2022 shot day at OMEGA are to: image an imploding inner cylinder as proof-of-principle for double cylinder experiments, measure the growth of pre-seeded perturbations on the inner cylinder, and measure the axial non-uniformity of the implosion with a sidelighter that provides a transverse view of the target. We will compare these experimental results to xRAGE (2D-only) and FLASH (2D and 3D) radiation-hydrodynamics calculations.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Post-Shot Report for OMEGA Double Cylinders (CylDRT 22B)

The direct-drive double cylinder experimental platform is a high-energy-density (HED) science platform designed to image an imploding cylindrical target. The target consists of a directly-driven outer cylinder and a shock-and-collision driven inner cylinder. The purpose of this platform is to study hydrodynamic instability growth on the inner cylinder, the outer surface of which is classically Rayleigh-Taylor unstable during the acceleration phase. We present results from recent experiments at the OMEGA laser facility. These experiments were designed as a proof-of-principle for the platform, using the same cylinder exterior dimensions and direct-drive beam configuration as previous single cylinder experiments. In these experiments, three sets of targets were fielded: no machined perturbations (smooth), a sinusoidal mode-10 perturbation on the outer surface of the inner cylinder, and a mode-20 perturbation on the outer surface of the inner cylinder. The primary diagnostic was a gated x-ray framing camera which imaged the backlit inner cylinder on-axis for sixteen frames over a time window of 1 ns for each shot. A second side-lit radiograph captured one image per shot, diagnosing axial uniformity. In this report we include an overview of the results from both the backlighter and the sidelighter diagnostics. We discuss at length the experimental analysis process. Finally, we present the results of the smooth target implosion trajectory and compare them to post-shot simulations. We see favorable agreement between simulation and experiment.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Hanford Double Shell Waste Tank Corrosion Studies (Final Report)

For fiscal year (FY) 2022, the Savannah River National Laboratory (SRNL) focused on two experimental tasks related to Hanford Double Shell Tank (DST) chemistry and integrity. The first task focused on understanding risk of corrosion due to formation of either continuous layers or discrete patches of solids on the tanks' inner sidewalls and bottoms. The tank bottom solids contact corrosion testing focused on studying the effects of forming a dry adherent solids layer on a carbon steel substrate. Long-term exposure tests and electrochemical tests were performed to investigate the effect of drying (i.e., removing water) from the solids phase. The second task focused on corrosion of the exterior of the secondary liner. In previous years, vapor corrosion inhibitors (VCIs) were investigated as a means of mitigating corrosion of the exterior of the secondary liner. During FY22 the utilization of nitrogen was explored as a means of corrosion mitigation. The corrosion test results with nitrogen were compared with the corrosion mitigation performance of the VCIs.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Double Shell Inertial Confinement Fusion X-Ray Spectral Analysis

At the National Ignition Facility (NIF), lasers are used to compress a double shell capsule with deuterium and tritium in order to create nuclear fusion processes. The lasers aim at the inside of a gold hohlraum which excite electrons which further release photons in the range of 0~20keV. The photons randomly disperse, ultimately either going towards the fuel capsule or back out the laser entrance holes. The photons that go towards the fuel capsule work towards the compression of the multi-shell capsule whereas the photons that leave the hohlraum have a chance at being picked up by the Lawrence Livermore National Lab’s ‘Dante’ photon detector. ‘Dante’ analyzes photon data by having 18 planar vacuum x-ray diodes (XRD) behind unique filters to differentiate data amongst various photon energies. The goal of the project was to analyze the characteristics of low and high energy photons released by the gold shell.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Multi-shock design tools in double shell models

The essence of the project was to implement a program in python that demonstrated certain models put forth by fusion physicists. Across the time spent at Los Alamos National Laboratory, much was spent programming. Though fundamentally programmatical in nature, the task contained considerable difficulty hid within mathematically deriving and manipulating the models while maintaining data discretization. The result of solving these complications gave invaluable experience in applied mathematics. The final product, a piece of lengthy code, ended up having the full range of desired capabilities, with plans for more. Given the laser power history from a pulse shot on NIF, Omega, or any other Inertial Confinement Fusion facility, the code maps the terrain of radiation temperature inside the hohlraum throughout the period of the shot. Additionally, shock wave convergence prediction was implemented as additional capability. As the name of the project suggests, this tool acts as a compass of direction for researchers designing laser power profiles. Further development of this tool will undoubtedly assist in the research conducted on single and double-shell indirect ICF, consequently expanding the capabilities of operating stewardship over the national nuclear stockpile.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Multi-shock design tools and shape transfer in double shells [Slides]

ICF researchers benefit by gaining immediate insight into indirect double-shell target physics. Manufacturing Hohlraum out of DU results in additional 6.5% energy “gained” in drive. Final results indicated the validity of Callahan’s model.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Quarknet Project: Simulating Double-Source Plane Lenses and Einstein Rings for Domain Adaptation

Double-Source Plane Lenses (DSPLs) are a form of strong gravitational lensing that can be used to uniquely constrain cosmological parameters like the dark energy equation of state. These objects are exceedingly rare: to date, only four have been discovered in astronomical surveys, like the Sloan Digital Sky Survey and the HyperSuprimeCam Survey. Additionally, the main features of these objects are typically co-located sets of arcs, which look like Einstein Rings of single-source galaxy-galaxy lenses. Larger astronomical surveys typically have low image resolution, which significantly exacerbates issues when trying to find DSPLs. Future surveys are likely to include many more of these objects and have higher image resolution. Traditional methods for finding strong lenses struggle to identify simple galaxy-galaxy lenses. Recently, neural networks have become the standard for lens identification, but these tools have not yet been used to search for DSPLs. In this work, we use the software deeplenstronomy to simulate varied images of DSPLs and Einstein Rings – with and without noise and artifacts of observational surveys, forming a comprehensive benchmark dataset of 40,000 images. We utilise this dataset to perform experiments with convolutional neural networks to discern between the two phenomena. Sofia Grimm and Jerry Zhou are co-first authors on this work.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Nuclear Matrix Elements for Neutrinoless Double-Beta Decay from Lattice QCD

Neutrinoless double-beta decay (0vbb) is a hypothetical nuclear decay that is only possible if the neutrino is a Majorana fermion. Experimental searches for this process with ever-increasing sensitivity have placed strong constraints on the 0vbb half-lives of relevant isotopes. Relating these experimental half-lives to the underlying particle physics -- the effective Majorana mass of the neutrino -- requires understanding of the nuclear matrix elements for the transition. These matrix elements can be computed within a nuclear effective field theory framework, but input from lattice QCD is necessary to constrain low-energy constants relevant for the decay. This talk will discuss calculations of these matrix elements using lattice QCD and the implications for determination of nuclear EFT parameters.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Double DVCS Measurement with the CLAS12 High-Luminosity Upgrade [Slides]

CLAS12 has a diverse physics program, with its detector commissioned in 2018 and since then acquiring physics data. The detector performance is close to design after improvements from AI-assisted tracking, but luminosity upgrades will greatly help efficiently execute the existing physics program and facilitate new physics opportunities. Two phases of luminosity increases are planned. The first, a doubling to 2x10 35 cm -2 s -1 , is in progress with an additional, fast tracking layer and en route in the next 3 years. The second, larger, phase, to 10 37 cm -2 s -1 , converts CLAS12’s forward acceptance region into a muon detector. μCLAS12 in the 2 nd phase is one of only two facilities in the world that can measure DDVCS, extending access to GPDs into new kinematic space. It also can provide, for example, access to heavy quarkonium.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Xenon-Doped Liquid Argon TPCs as a Neutrinoless Double Beta Decay Platform

Next-generation large liquid argon time-projection chambers offer an unprecedented amount of active detector mass in a deep location. Modifications to the detector design could enable neutrinoless double beta decay searches, with the possibility of reaching the normal ordering region. These modifications include adding external neutron moderation, filling the detector with argon depleted in Ar42, doping with xenon, and a method to achieve percent-level energy resolution at the MeV scale. One way to achieve this desired level of energy resolution is to introduce a photosensitive dopant into the argon, converting the isotropic scintillation photons into a directional ionization signal. This would enhance the achievable energy resolution in large LArTPCs, and would lead to sizeable improvements to many facets of the broad physics program such a detector could offer.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Yield requirements for studies of double (n,2n) reactions on dopant material in NIF Capsules

At the National Ignition Facility (NIF) inertial confinement fusion (ICF) ignition has been achieved, involving yields up to about 5 MJ. In addition, it has been suggested that proposed advances at the NIF facility, involving moderate upgrades in laser energy, could further increase fusions gains to yields in the 30-40 MJ range. Such high yield would open the possibility for new studies in many areas of science. In the present analysis, we focus on how these possible future fusion yields would make measurements of multi-step nuclear reactions on dopant material practical. For this, we consider the scenario of loading dopant material into the ablator of cryogenic capsules and estimate yields needed to measure previously inaccessible double (n,2n) reactions under ICF conditions.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

Hanford Double Shell Waste Tank Corrosion Studies (Final Report FY2023)

For fiscal year (FY) 2023, the Savannah River National Laboratory (SRNL) focused on two experimental tasks related to Hanford Double Shell Tank (DST) chemistry and integrity. The first task focused on understanding risk of corrosion due to formation of either continuous layers or discrete patches of solids on the tanks’ inner sidewalls and bottoms. Differences in the conductivity between various layers of the tank (e.g., solids, liquid, etc.) could result in differences in the electrochemical potential of the tank metal at various locations. The electrochemical potential difference may result in a corrosion current between the coupled surfaces. In FY23, SRNL investigated test configurations and protocols that could evaluate the presence of a galvanic couple between the tank bottom and the tank wall.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗

Fabrication of the HFVMTF Double-Bath Cryostat

The High Field Vertical Magnet Test Facility (HFVMTF) at Fermilab is designed to test superconducting magnets up to 20 tons and 1.3 meters in diameter. Central to the facility is a double-bath superfluid helium cryostat reaching 1.8 K at 1.2 bar. Integrated with a 15 T superconducting dipole from LBNL, HFVMTF supports HTS cable testing for fusion applications. This paper presents the design and fabrication of the cryostat, with a focus on two complex components: the 2 K heat exchanger and the lambda plate. The heat exchanger thermally links sub-atmospheric and pressurized helium baths. The 1.4-meter lambda plate provides thermal isolation and structural support for over 20 tons under 1.3 bar pressure differential. Finite Element Analysis validated the vessel’s integrity under maximum load conditions.

Bruce, Romain [Fermilab] (ORCID:0000000234200612)↗

Hanford Double Shell Waste Tank Corrosion Studies- Final Report FY2024

For fiscal year (FY) 2024, the Savannah River National Laboratory (SRNL) focused on two experimental tasks related to Hanford Double Shell Tank (DST) chemistry and integrity. The first task focused on understanding risk of corrosion due to formation of either continuous layers or discrete patches of solids on the tanks’ inner sidewalls and bottoms. The objective of this task was to determine the effect of solid deposits on the corrosion risk to the tank bottom, and whether a combination of scale, saltcake and loose solids lead to under deposit corrosion. Electrochemical testing in a single cell arrangement was employed to determine a threshold inhibitor level for the interstitial liquid in the solids, above which carbon steel was not susceptible to corrosion beneath the solids. The inhibitor levels tested were based on the previously determined probability of failure for carbon steel in a simulated waste (i.e., Pitting Factor).

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗