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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.

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At least 253 records · Page 14
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Sensors of world’s largest digital camera snap first 3,200-megapixel images at SLAC

Vera C. Rubin Observatory will conduct the 10-year Legacy Survey of Space and Time (LSST), which will collect 60 petabytes of data to address some of the most pressing questions about the structure and evolution of the universe and the objects in it. LSST is designed to address four science areas: Understanding Dark Matter and Dark Energy Hazardous Asteroids and the Remote Solar System The Transient Optical Sky The Formation and Structure of the Milky Way Vera C. Rubin Observatory is a federal project jointly funded by the National Science Foundation and the Department of Energy Office of Science, with early construction funding received from private donations through the LSST Corporation. The NSF-funded LSST (now Rubin Observatory) Project Office for construction was established as an operating center under the management of the Association of Universities for Research in Astronomy (AURA). The DOE-funded effort to build the Rubin Observatory LSST Camera (LSSTCam) is managed by SLAC.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2022

Super resolution for magneto-optical microscopy

Sub-diffraction limited magneto-optical microscopy, such as Kerr or Faraday effect microscopy, provide many advantages to fields of science and technology for measuring, or imaging, the magnetization structures and magnetization domains of materials. Disclosed is a method and system for performing sub-diffraction limited magneto-optic microscopy. The method includes positioning a microlens or microlens layer relative to a surface of a sample to image the surface of the sample, forming a photonic nanojet to probe the surface of the sample, and receiving light reflected by the surface of the sample or transmitted through the sample at an imaging sensor. The methods and associated systems and devices enable sub-diffraction limited imaging of magnetic domains at resolutions 2 to 8 times the classical diffraction limit.

te Velthuis, Suzanne Gabriëlle Everdine↗
DOE OSTI2022

Analysis of synthetic electron cyclotron emission from the high field side of HL-2M tokamak plasmas

A synthetic electron cyclotron emission (ECE) diagnostic is used to interpret ECE signals from preset plasma equilibrium profiles, including magnetic field, electron density, and electron temperature. According to the simulation results, the electron temperature (T e ) profile covering the harmonic overlap region can be obtained by receiving ECE signals at the high field side (HFS) of the HL-2M plasma. The third harmonic ECE at the low field side (LFS) cannot pass through the second harmonic resonance layer at the HFS unless the optical thickness (τ) of the second harmonic becomes gray (τ ≤ 2). In addition, the impact of the relativistic frequency down-shift has been evaluated and corrected. The measurable range of the HFS ECE has been calculated by scanning different parameters (electron density, temperature, and magnetic field). Higher plasma parameters allow a wider radial range of electron temperature measurements. The minimum inner measurable position can reach R = 120 cm (r/a = -0.89) when the product of core temperature (T e0 ) and density (n e0 ) is greater than 35 × 10 19 keV m -3 , which is extended by more than 30 cm inward compared with that of the LFS measurement. The HFS ECE will greatly improve the diagnostic ability of ECE systems on the HL-2M tokamak.

47 OTHER INSTRUMENTATION↗
DOE OSTI2023

Multimodal nonlinear optical imaging via evanescent wave excitation

A system for multimodal nonlinear optical imaging is provided. Each mode uses a high NA objective to cause total internal reflection excitation at a sample-substrate interface. The system has a femtosecond oscillator to generate pulses used for two beams. The objective receives at least one beam, redirects the received at least one beam through a dielectric substrate to cause the TIR and produces corresponding evanescent waves in a portion of the sample adjacent to the sample-substrate interface, and collects a backward-propagating beam of pulses of responsive light. The portion of the sample illuminated by the evanescent waves emits responsive light. Different modes or combinations of the distinct modalities may be selected to access complementary chemical and structural information for various chemical species near the sample-substrate interface. Each mode may have mode-specific control such as selective beam blocking, power ratios and filtering.

Doughty, Benjamin L.↗
DOE OSTI2021

Remote quantum state transfer for qubits with different frequencies

A quantum communication system includes a first quantum transceiver, a second quantum transceiver, and a quantum communication mediator (QCM) system. The transceivers have different resonant frequencies or physical systems. The QCM system receives an initial quantum signal from the first quantum transceiver. The QCM system transfers a quantum state of the initial quantum signal to a first mechanical signal and then from the first mechanical signal to a first pair of optical signals by way of a first three-wave mixing process. The QCM transfers the quantum state to a second pair of optical signals from the first pair by way of a four-wave mixing process. The QCM transfers the quantum state from the second pair of optical signals to a second mechanical signal by way of a second three-wave mixing process. The QCM transfers the quantum state from the second mechanical signal to a final quantum signal by mechanical transduction.

Soh, Daniel Beom Soo↗
DOE OSTI2022

System and method for remote detection and location of gas leaks

A system for monitoring for a gas leak from a gas containing structure is disclosed. The system includes a lens that directs an image of a scene of interest through an optical filter onto a detector. The filter is associated with the lens and the filter has one or more passbands that passes wavelengths which match one or more emission or reflectively wavelengths of the gas being monitored. A detector receives the image after the image passes through the lens and the filter. The detector generates image data representing the scene including the gas containing structure. A processor is configured to process the image data by executing machine executable code stored on a memory. The machine executable code processes the image data to identify turbulence flows in the image data such that turbulence flow indicates a gas leak, and generate and send an alert in response to the identification of a turbulence flow.

O'Neill, Mary D.↗
DOE OSTI2020

Design and Testing of the Address in Real-Time Data Driver Card for the Micromegas Detector of the ATLAS New Small Wheel Upgrade

The Address in Real Time Data Driver Card (ADDC) is designed to transmit the trigger data in the Micro-Mesh Gaseous Structure (Micromegas) detector of the ATLAS New Small Wheel (NSW) upgrade. The Address in Real Time (ART) signals are generated by the front-end ASIC, named VMM chip, to indicate the address of the first above-threshold event. A custom ASIC (ART ASIC) is designed to receive the ART signals from the VMM chip and implement the hit-selection. The processed data from the ART ASIC will be transmitted out of the NSW through the GBTx serializer, the unidirectional Versatile Twin Transmitter (VTTx) and fiber optical links. The ART signal is critical for the ATLAS experiment trigger selection thus the performance and stability of the ADDC is very important. To ensure extensive testing of the ADDC, an FPGA Mezzanine Card (FMC) based testing platform and a special designed firmware/software are developed. We find that this test platform works with the commercial Xilinx VC707 FPGA development kit, independent of the other electronics of the NSW it can test all the functions of the ADDC and its long-term stability. This paper will introduce the design, testing procedure and results of the ADDC and the FMC testing platform.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2022

Science & Technology Review: Awards for Livermore Innovation

At Lawrence Livermore National Laboratory, we focus on science and technology research to ensure our nation’s security. We also apply that expertise to solve other important national problems in energy, bioscience, and the environment. Science & Technology Review (S&TR) is published eight times a year to communicate, to a broad audience, the Laboratory’s scientific and technological accomplishments in fulfilling its primary missions. The publication’s goal is to help readers understand these accomplishments and appreciate their value to the individual citizen, the nation, and the world. In 2021, Lawrence Livermore technologies received three R&D 100 awards, which honor the year’s top 100 innovations from around the world. The feature article beginning on p. 4 describes the Laboratory’s winners: the Multiplicity Counter for Thermal and Fast Neutrons, Flux, and the Optical Transconductance Varistor. The 2021 awards raised the Laboratory’s total R&D 100 awards to 173 since 1978. The R&D 100 logo is reprinted in this issue with permission from R&D World magazine.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2021

Remote optical wind detection and aerodynamic control system for ground vehicle

An aerodynamic control system for a ground vehicle comprises a LiDAR module including at least one LiDAR sensor configured to obtain wind data upstream of the ground vehicle; a computing device; an aerodynamic device controller; and an aerodynamic device including a control surface. The computing device is configured to receive the wind data from the LiDAR module and generate output signals based on the wind data. The aerodynamic device controller is configured to receive the output signals from the computing device and generate control signals to control the aerodynamic device to adjust aerodynamic properties of the ground vehicle based at least in part the wind data. Changes to the configuration of the control surface may include increasing or decreasing a deflection angle of the at least one aerodynamic device. The aerodynamic device may include, e.g., a pneumatically actuated aerodynamic device or an electro-mechanically actuated aerodynamic device.

Damon, Kenneth H.↗
DOE OSTI2021

High-Latitude Stratospheric Aerosol Geoengineering Can Be More Effective if Injection Is Limited to Spring

Stratospheric aerosol geoengineering focused on the Arctic could substantially reduce local and worldwide impacts of anthropogenic global warming. Because the Arctic receives little sunlight during the winter, stratospheric aerosols present in the winter at high latitudes have little impact on the climate, whereas stratospheric aerosols present during the summer achieve larger changes in radiative forcing. Injecting SO 2 in the spring leads to peak aerosol optical depth (AOD) in the summer. We demonstrate that spring injection produces approximately twice as much summer AOD as year-round injection and restores approximately twice as much September sea ice, resulting in less increase in stratospheric sulfur burden, stratospheric heating, and stratospheric ozone depletion per unit of sea ice restored. Furthermore, we also find that differences in AOD between different seasonal injection strategies are small compared to the difference between annual and spring injection.

58 GEOSCIENCES↗
DOE OSTI2020

Galaxy Clusters Selected via the Sunyaev–Zel’dovich Effect in the SPTpol 100-square-degree Survey

In this work, we present a catalog of galaxy cluster candidates detected in 100 square degrees surveyed with the SPTpol receiver on the South Pole Telescope. The catalog contains 89 candidates detected with a signal-to-noise ratio greater than 4.6. The candidates are selected using the Sunyaev–Zel'dovich effect at 95 and 150 GHz. Using both space- and ground-based optical and infrared telescopes, we have confirmed 81 candidates as galaxy clusters. We use these follow-up images and archival images to estimate photometric redshifts for 66 galaxy clusters and spectroscopic observations to obtain redshifts for 13 systems. An additional two galaxy clusters are confirmed using the overdensity of near-infrared galaxies only and are presented without redshifts. We find that 15 candidates (18% of the total sample) are at redshift z ≥ 1.0, with a maximum confirmed redshift of ${z}_{\max }=1.38\pm 0.10$. We expect this catalog to contain every galaxy cluster with ${M}_{500c}\gt 2.6\times {10}^{14}{M}_{\odot }{{h}}_{70}^{-1}$ and z > 0.25 in the survey area. The mass threshold is approximately constant above z = 0.25, and the complete catalog has a median mass of approximately ${M}_{500c}=2.7\times {10}^{14}{M}_{\odot }{{h}}_{70}^{-1}$. Compared to previous SPT works, the increased depth of the millimeter-wave data (11.2 and 6.5 μK-arcmin at 95 and 150 GHz, respectively) makes it possible to find more galaxy clusters at high redshift and lower mass.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2022

Four-year Cosmology Large Angular Scale Surveyor (CLASS) Observations: On-sky Receiver Performance at 40, 90, 150, and 220 GHz Frequency Bands

The Cosmology Large Angular Scale Surveyor (CLASS) observes the polarized cosmic microwave background (CMB) over the angular scales of 1° ≲ θ ≤ 90° with the aim of characterizing primordial gravitational waves and cosmic reionization. We report on the on-sky performance of the CLASS Q-band (40 GHz), W-band (90 GHz), and dichroic G-band (150/220 GHz) receivers that have been operational at the CLASS site in the Atacama desert since 2016 June, 2018 May, and 2019 September, respectively. We show that the noise-equivalent power measured by the detectors matches the expected noise model based on on-sky optical loading and lab-measured detector parameters. Using Moon, Venus, and Jupiter observations, we obtain power to antenna temperature calibrations and optical efficiencies for the telescopes. From the CMB survey data, we compute instantaneous array noise-equivalent-temperature sensitivities of 22, 19, 23, and 71 $\mu {{\rm{K}}}_{\mathrm{cmb}}\sqrt{{\rm{s}}}$ for the 40, 90, 150, and 220 GHz frequency bands, respectively. These noise temperatures refer to white noise amplitudes, which contribute to sky maps at all angular scales. Future papers will assess additional noise sources impacting larger angular scales.

Observational cosmology↗
DOE OSTI2020

Characterizing the Sensitivity of 40 GHz TES Bolometers for BICEP Array

The BICEP/Keck (BK) experiment aims to detect the imprint of primordial gravitational waves in the cosmic microwave background polarization, which would be direct evidence of the inflation theory. While the tensor-to-scalar ratio has been constrained to be $r_{0.05}<0.06$ at 95% c.l., further improvements on this upper limit are hindered by polarized galactic foreground emissions and removal of gravitational lensing polarization. The 30/40 GHz receiver of the BICEP Array (BA) will deploy at the end of 2019 and will constrain the synchrotron foreground with unprecedented accuracy within the BK sky patch. We will show the design of the 30/40 GHz detectors and test results summarizing its performance. The low optical and atmospheric loading at these frequencies requires our TES detectors to have low saturation power in order to be photon noise dominated. To realize the low thermal conductivity required from a 250 mK base temperature, we developed new bolometer leg designs. We will present the relevant measured detector parameters: $G, T_c, R_n, P_{sat}$, and spectral bands, and noise spectra. We achieved a per bolometer NEP including all noise components of 2.07×10 -17 W/$\sqrt{Hz}$, including an anticipated photon noise level 1.54×10 -17 W/$\sqrt{Hz}$.

47 OTHER INSTRUMENTATION↗
DOE OSTI2020

A cryogenic continuously rotating half-wave plate mechanism for the POLARBEAR-2b cosmic microwave background receiver

In this report we present the design and laboratory evaluation of a cryogenic continuously rotating half-wave plate (CHWP) for the POLARBEAR-2b (PB-2b) cosmic microwave background receiver, the second installment of the Simons Array. PB-2b will observe at 5200 m elevation in the Atacama Desert of Chile in two frequency bands centered at 90 GHz and 150 GHz. In order to suppress atmospheric 1/f noise and mitigate systematic effects that arise when differencing orthogonal detectors, PB-2b modulates linear sky polarization using a CHWP rotating at 2 Hz. The CHWP has a 440 mm clear aperture diameter and is cooled to ≈50 K in the PB-2b receiver cryostat. It consists of a low-friction superconducting magnetic bearing and a low-torque synchronous electromagnetic motor, which together dissipate < 2 W. During cooldown, a grip-and-release mechanism centers the rotor to < 0.5 mm, and during continuous rotation, an incremental optical encoder measures the rotor angle with a noise level of 0.1 μrad/Hz. We discuss the experimental requirements for the PB-2b CHWP, the designs of its various subsystems, and the results of its evaluation in the laboratory. The presented CHWP has been deployed to Chile and is expected to see first light on PB-2b in 2020 or 2021.

47 OTHER INSTRUMENTATION↗
DOE OSTI2024

Laser Based Ultrasound for Verification of Circuit Card Assemblies

This IR is a follow-up conference Paper to the IR approved abstract; PNNL-SA-194096. --- Verification that equipment is authentic and not changed; even at the circuit card assembly (CCA) level will likely be an important component of future arms control treaties. This effort was an initial evaluation of the potential for laser-based ultrasound (LBU) as an inspection tool for Unique Identification (UID) of Circuit Card Assembly (CCA) boards and CCA components. The LBU system used a laser pulse for ultrasound generation and an Optical Microphone for ultrasound detection to image subsurface structures without physical contact and in a dry state. This paper described the selected CCA surrogate, CCA components that were examined, the LBU system, LBU images of the CCA components, and the initial development of UID algorithms. Receiver operating characteristics (ROC) curves indicated good performance for two algorithms as a potential means for UID of CCA boards and CCA components.

Laser Ultrasound, Equipment Verification, Arms Con↗
DOE OSTI2021

Characterization of mechanical deformation in aluminum by optical second harmonic generation

Second harmonic generation (SHG), a laser-based surface technique, was used to characterize near-surface defect evolution associated with mechanical deformation in 2024-T3 aluminum due to tensile loads. Electron backscatter diffraction (EBSD) measurements were also performed to determine the geometrically necessary dislocation density before and after tensile deformation. Comparison of the EBSD and SHG results found that dislocation density and SHG signal are inversely proportional; tensile deformation in the plastic regime led to an increase in dislocation density and a decrease in SHG response. A similar trend was seen in the SHG results on as-received (unpolished) Al samples; SHG response decreases with extent of plastic deformation. Furthermore, this study suggests that SHG has potential as a nondestructive evaluation technique.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Multi-chip photonics transceiver

A photonics transceiver is described herein, wherein the photonics transceiver exhibits improved areal bandwidth density and improved energy per bit consumption relative to conventional photonics transceivers. The photonics transceiver achieves an areal bandwidth density of at least 5 Tbps/mm2 with an energy consumption of less than 500 fJ/bit (sum of energy consumed for both a transmitted bit and a received bit). The photonics transceiver is a multi-chip module, where chips in the multi-chip module are tightly integrated with one another. The multi-chip module includes light source, photodetector, photonics, and control/logic chips. The photonics chip includes transparent conducting oxide integrated optical modulators and multiplexers and demultiplexers based on MEMS-tunable optical ring resonators.

Wood, Michael↗
DOE OSTI2020

Optical fiber receptacle cover

A cover for partially covering and protecting cables plugged into a receptacle is provided. The receptacle includes a face plate with a first hole through which a first fastener secures the face plate to a face of the receptacle. The cover comprises a plurality of walls at least partially defining a hollow chamber, a slot adjacent to the chamber and configured to receive the face plate when the cover is slid over the face plate, an opening that leads to the chamber and the slot, and a first channel extending partially through the chamber and configured to provide access to the fastener.

42 ENGINEERING↗