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Suitability of Altair FEKO's Computational Electromagnetic Techniques for Tree Model Scattering and Penetration at Ku-band

Jaramillo, Monica J.; Doerry, Armin; Christodoulou, Christos G.

Foliage penetration (FOPEN) radar at lower frequencies (VHF, UHF) is a well-studied area with many contributions. However, there is growing interest in using higher Ku-band frequencies (12-18 GHz) for FOPEN. Specifically, the reduced wavelength sizes provide some key saliencies for developing more optimized detection solutions. The disadvantage is that exploiting Ku-band for FOPEN is complicated because higher frequencies have pronounced scattering effects due to their smaller wavelengths. A methodology h as been developed to model and simulate FOPEN problems that characterize the phenomenology of Ku-band electromagnetic ( EM ) wave transmissions through moderate foliage. The details of this research (i.e. the realistic tree models, simulation setup and results) are documented in multiple reports. The main focus of this report is to describe the preliminary validation and verification of Altair FEKO, the computational EM (CEM) software used for this research, as well as present a simplified symmetrical tree model and an introductory CAD tree model.

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TYPE SAND Report YEAR 2021
DOIOSTI

Statement of Work. Y-12 National Security Complex Security Infrastructure Revitalization Program Project - Combination Inspector

Fox, Lora R.; Powledge, Laura B.

The Y-12 SIRP Quadrant 1, Quadrant 2, and Vehicle Barrier project involves the following summary elements. The perimeter intrusion detection and assessment system (PIDAS) is an existing system at the Y-12 National Security Complex, which is a government-owned facility located in Oak Ridge, Tennessee, and managed by Consolidated Nuclear Security, LLC (CNS) for the Department of Energy (DOE). National Technology and Engineering Solutions of Sandia, LLC (NTESS) is the engineering design agent and construction manager (CM) for the Y-12 SIRP effort. The Quadrants 1 and 2 portion of the project involves the replacement of the PIDAS, and the vehicle barrier portion of the project involves the installation of a continuous passive vehicle barrier alongside the inner PIDAS fence.

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TYPE Other Report YEAR 2021
DOIOSTI

Hazardous Chemical Inventory Guidelines, Purpose, and Process

Cudney-Black, Jane E.; Fritz, Hugh F.; Garcia, Matthew A.; Robinson, Sean S.; Ross, Tonya; Castillo, Brian D.

The Environment, Safety, and Health Planning department at Sandia National Laboratories is interested in the purchase and storage of chemicals and their potential impact following an uncontrolled release. The large number of projects conducted at SNL make tracking every chemical purchase impractical; therefore, attention is focused on hazardous substances purchased in large quantities. Chemicals and quantities of concern are determined through regulatory guidelines; e.g., the OSHA Process Safety Management list, the EPA Risk Management Plan list, and the Department of Energy Subcommittee on Consequence Assessment and Protective Actions Emergency Response Planning Guidelines. Based on these regulations, a list of chemicals with quantities of concern was created using the Aerial Locations of Hazardous Atmospheres (ALOHA) and SCREEN View chemical dispersion modelling software. The nature of this report does not draw conclusions, rather it documents the logic for a chemicals of concern list to ensure compliance with various regulations and form the basis for monitoring chemicals that may affect hazard classification. Hazardous Chemical Inventory Guidelines, Purpose, and Process 4 This page left blank.

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TYPE SAND Report YEAR 2021
DOIOSTI

Simulation and Modeling of Time-Resolved X-Ray Detector for the Saturn Accelerator

IEEE Transactions on Nuclear Science

Gao, Xujiao G.; Looker, Quinn M.; Webb, Timothy J.; Depriest, Kendall D.; Ulmen, Benjamin A.

We present the technology-aided computer design (TCAD) device simulation and modeling of a silicon p-i-n diode for detecting time-dependent X-ray radiation. We show that the simulated forward and reverse breakdown current-voltage characteristics agree well with the measured data under nonradiation environment by only calibrating carrier lifetimes for the forward bias case and avalanche model critical fields for the reverse bias condition. Using the calibrated parameters and other nominal material properties, we simulated the radiation responses of the p-i-n diode and compared with experimental data when the diode was exposed to X-ray radiation at Sandia's Saturn facility and the Idaho State University (ISU) TriMeV facility. For Saturn's Gaussian dose-rate pulses, we show three findings from TCAD simulations. First, the simulated photocurrents are in excellent agreement with the measured data for two dose-rate pulses with peak values of 1.16 times 10 -{10} and 1.88 times 10 -{10} rad(Si)/s. Second, the simulation results of high dose-rate pulses predict increased delayed photocurrents with longer time tails in the diode electrical responses due to excess carrier generation. Third, simulated peak values of diode radiation responses versus peak dose rates at different bias conditions provide useful guidance to determine the dose-rate range that the p-i-n diode can reliably detect in experiment. For TriMeV's non-Gaussian dose-rate pulse, our simulated diode response is in decent agreement with the measured data without further calibration. We also studied the effects of device geometry, recombination process, and dose-rate enhancement via TCAD simulations to understand the higher measured response in the time after the peak dose-rate radiation for the p-i-n diode exposed to TriMeV irradiation.

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TYPE Journal Article YEAR 2021
DOIOSTIScopus

Evaluation of Guardbanding Methods for Calibration and Product Acceptance

Delker, Collin J.

The Primary Standards Lab employs guardbanding methods to reduce risk of false acceptance in calibration when test uncertainty ratios are low. Similarly, production agencies guardband their requirements to reduce false accept rates in product acceptance. The root-sum-square guardbanding method is recommended by PSL, but many other guardbanding methods have been proposed in literature or implemented in commercial software. This report analyzes the false accept and reject rates resulting from the most common guardbanding methods. It is shown that the root-sum-square method and the Dobbert Managed Guardband strategy are similar and both are suitable for calibration and product acceptance work in the NSE.

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TYPE SAND Report YEAR 2021
DOIOSTI

Salt International Collaborations FY2021 Update

Kuhlman, Kristopher L.; Matteo, Edward N.; Mills, Melissa M.; Jayne, Richard S.; Reedlunn, Benjamin R.; Sobolik, Steven R.; Laros, James H.; Stein, Emily S.; Gross, Michael B.

This report summarizes the international collaboration work conducted by Sandia and funded by the US Department of Energy Office (DOE) of Nuclear Energy Spent Fuel and Waste Science & Technology (SFWST) as part of the Sandia National Laboratories Salt R&D and Salt International work packages. This report satisfies the level-three milestone M3SF-20SN010303062. Several stand-alone sections make up this summary report, each completed by the participants. The sections discuss international collaborations on geomechanical benchmarking exercises (WEIMOS), granular salt reconsolidation (KOMPASS), engineered barriers (RANGERS), and model comparison (DECOVALEX). Lastly, the report summarizes a newly developed working group on the development of scenarios as part of the performance assessment development process, and the activities related to the Nuclear Energy Agency (NEA) Salt club and the US/German Workshop on Repository Research, Design and Operations.

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TYPE Other Report YEAR 2021
DOIOSTI

Atomic-precision advanced manufacturing for Si quantum computing

MRS Bulletin

Bussmann, Ezra B.; Butera, Robert E.; Owen, James H.G.; Randall, John N.; Rinaldi, Steven R.; Baczewski, Andrew D.; Misra, Shashank M.

A materials synthesis method that we call atomic-precision advanced manufacturing (APAM), which is the only known route to tailor silicon nanoelectronics with full 3D atomic precision, is making an impact as a powerful prototyping tool for quantum computing. Quantum computing schemes using atomic (31P) spin qubits are compelling for future scale-up owing to long dephasing times, one- and two-qubit gates nearing high-fidelity thresholds for fault-tolerant quantum error correction, and emerging routes to manufacturing via proven Si foundry techniques. Multiqubit devices are challenging to fabricate by conventional means owing to tight interqubit pitches forced by short-range spin interactions, and APAM offers the required (Å-scale) precision to systematically investigate solutions. However, applying APAM to fabricate circuitry with increasing numbers of qubits will require significant technique development. Here, we provide a tutorial on APAM techniques and materials and highlight its impacts in quantum computing research. Finally, we describe challenges on the path to multiqubit architectures and opportunities for APAM technique development. Graphic Abstract: [Figure not available: see fulltext.]

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TYPE Journal Article YEAR 2021
DOIOSTIScopus
Results 9801–9900 of 96,771
Results 9801–9900 of 96,771