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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 19 records
All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

The impact of optical measurement techniques on measured aerosol particle size distributions

Ambient aerosol particle size distributions measured by the Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) at various sites around the world exhibit modes at optical diameters near 600 nm and 850 nm. These modes are not present in concurrent measurements with the Grimm 11-D Optical Particle Counter (OPC). Here, in this study, we argue that these modes result from the optical measurement technique itself, and we explain why they appear in measurements by the UHSAS but not in those by the Grimm OPC. We construct computer models of the UHSAS and Grimm (“digital UHSAS” and “digital Grimm”) and use these to investigate the size distribution that would result from measurements of artificial aerosol particle size distributions that do not contain modes. The appearance of modes for the structureless incoming size distributions sampled by the digital UHSAS is explained by the nonlinear behavior of partial scattering cross sections of uniform spherical particles as a function of their diameter. The absence of modes in the digital Grimm is explained by the coarser size resolution of that instrument. Detailed analysis of the relationship between optical and geometric diameters for uniform spherical particles reveals two important results. First, these diameters generally have different numerical values for the same particle, and second, the relationship is nonlinear; thus, widths of size bins in terms of optical diameter differ from those in geometric diameter. These results explain the modes observed in the ambient size distributions and highlight concerns with attempts to create a merged size distribution by combining measurements from different instruments.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2019

Micro-slotting Residual Stress Measurement Technique for Understanding Fatigue Performance of Open-Hole Ti-6Al-4V Samples

Micro-slotting, a microscale relaxation residual stress measurement technique, has been shown in recent years to be a reliable method for measuring local residual stresses in metallic materials. This study demonstrates the unique application of the micro-slotting residual stress measurement technique for measuring near-edge tangential residual stresses around cold-expanded holes in Ti-6Al-4V plates. Knowledge of the near-edge elastic strains induced by the hole processing, in combination with plastic strain information obtained using electron backscatter diffraction, allowed for interpretation of fatigue life differences and crack growth behavior between the as-drilled and cold-expanded conditions. The similar crack initiation lives of the as-drilled and cold-expanded open-hole coupons were attributed to the similar elastic and plastic strains present at the hole edges. The subsequent crack growth resistance observed for the cold-expanded holes was a result of the large compressive residual stress region induced by cold expansion.

36 MATERIALS SCIENCE↗
DOE OSTI2026

New measurement techniques for gear-changing research using DESIREE

In this work we cover some of the newer techniques developed to measure the effects of a gear changing system maintained in DESIREE at Stockholm University. Gear-changing is a collider synchronization method where two rings with different harmonic numbers in them maintain collisions through different velocities, pathlengths or a combination of the two. This system has been demonstrated using the low energy ion collider DESIREE at Stockholm university. We have not only continued our previous methods of studying the beam using a repeating pattern technique where one bucket in each ring is intentionally left empty, but we now also use recently installed pickups outside of the merger region to study the beams separately while they collide.

Accelerator Physics↗
DOE OSTI2025

Comparison of measurement techniques and sorption of radium-226 in low and high salinity aqueous samples

Human activities have the potential to redistribute radium (Ra) in the marine environment in a manner that may necessitate monitoring or management of subsequent human or environmental exposures. There is therefore a need to identify accurate and accessible techniques for Ra measurement in high salinity samples and to describe the distribution of Ra in estuarine and marine environments, but most efforts in these areas have focused on low salinity matrices. In addition, rapid and reliable measurements are crucial for time-sensitive samples such as short-lived isotopes or emergency situations. The objective of this study is to describe the limits of detection, cost, and relative ease for measurement of Ra in both low and high salinity aqueous samples via three analytical methods: liquid scintillation counting (LSC), high purity germanium (HPGe) gamma spectrometry, and inductively coupled plasma mass spectrometry (ICP-MS). To contextualize these measurements for real-world scenarios, the partitioning of 226 Ra to substrates relevant to the marine environment was also characterized. Although HPGe detection with solid phase extraction had the lowest limit of detection for low salinity samples (0.27 Bq L −1 ), poor 226 Ra recovery for high salinity samples and high materials costs make this method prohibitive for many users. Limits of detection for high salinity samples were lower for LSC (1.28 Bq L −1 ) than for ICP-MS without dilution (11.4 Bq L −1 ), but significant and unexpected degradation of the high salinity LSC standards was observed after six months. Furthermore, our preferred measurement method for high salinity Ra samples is ICP-MS with sample dilution as necessary to reduce matrix effects.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2021

UNESE Argon-39 Measurement Techniques: Developing an above-ground Argon-39 Measurement Capability

The Underground Nuclear Explosion Signatures Experiment (UNESE) sought to use 37 Ar as a tracer for measuring noble-gas migration in the soil surrounding historic Underground Nuclear Explosions (UNE). One unexpected observation was the presence of the much longer-lived isotope 39 Ar from historic UNEs. Quantifying the activity of 39 Ar proved difficult due to the lack of capability to measure significantly-above-background levels of 39 Ar and a general discomfort to repeatedly expose Ultra-Low-Background Proportional Counters (ULBPCs) to significant radioactivity. Because the whole-air samples collected for the 37 Ar tracer measurement were already being measured on the above-ground argon capability, it was decided to expand that capability to include 39 Ar. This document describes the efforts required to achieve quantitative reporting of the 39 Ar backgrounds measured during experiments at the sites of the historic Barnwell and Disko Elm UNEs.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2025

Measurement techniques using the electron beam profile scanner at the Fermilab Main Injector

This work presents techniques for non-invasive transverse profile measurements of high-intensity proton beams using an Electron Beam Profile Scanner (EBPS). The EBPS utilizes low-energy electrons as a probe to analyze the transverse size of proton beams, allowing for potential analysis on a single-bunch basis. Recent upgrades to the Fermilab Main Injector have enhanced beam power on target to 1 MW, with future developments targeting 2 MW. The higher beam power has increased the demand for non-invasive diagnostics, as invasive methods can disrupt operations.The techniques presented include 1) the slow scan technique, which serves as a proof of concept for the probe beam, 2) the one-shot scan technique for measuring horizontal beam profiles, and 3) the raster scan technique for analyzing horizontal beam profiles as a function of the longitudinal distribution of the beam. The profiles obtained will be crucial for studying and understanding instabilities in high-power, high-intensity proton beams. This will contribute to optimizing the operation of high-power proton accelerators by minimizing beam loss, activation, and damage to both the diagnostics and the accelerator components.

Mwaniki, Matilda [IIT, Chicago]↗
DOE OSTI2023

Experimental study on the startup of the annular wick type heat pipe using fiber optical temperature measurement technique

This study used optical fiber-distributed temperature sensors to measure the internal and external temperature distributions of a water-cooled heat pipe. The sensor technology used in this study is fiber optical distributed temperature sensing, a distributed sensing technique based on the naturally occurring Rayleigh backscatter in optical fibers. This measurement technique provides maximum spatial resolution for static and semi-static applications. Using this sensor, the temperature distribution of the heat pipe's internal, external, vapor core, and the wick was measured with a spatial resolution of 0.65 mm, a sampling frequency of 40 Hz, and a temperature resolution of 0.1 °C. Through the measured temperature distribution database, the starting phenomenon, the effective length trend, and the limitation onset were observed. From the results, it is found that a high-temperature peak appears at the evaporator if a high initial power (75 W) is imposed on the heat pipe, even after the heat pipe approaches the normal operating status. The peak is not observed in a slower startup (30 W initial power then slowly increased to 75 W). It is also found that the temperature distributions and effective condenser length of the heat pipe highly depend on the cooling conditions. There are variations in the temperature according to the radial direction of the horizontal heat pipe due to gravity. In conclusion, lead and lag of the temperature evolution were observed at the onset of the operating limitations.

42 ENGINEERING↗
DOE OSTI2025

Analysis Background & Noise in Stretched Wire Alignment Technique Measurements

The Stretched-Wire Alignment Technique (SWAT) is one method of magnet alignment for linear induction accelerators. The applications of SWAT have been implemented for aligning solenoid magnets on the Scorpius linear induction accelerator which will be sited at the Nevada National Security Site and the Flash X-Ray (FXR) linear induction accelerator at Lawrence Livermore National Laboratory’s Contained Firing Facility. This article describes both systematic (repeatable) and random sources of background and noise as well as practical ways to eliminate or reduce them to acceptable levels. Systematic sources include reflections from wire ends, rapid sag due to ohmic heating of the wire, magnetic materials, and shot rate. Random sources include air currents, vibration of nearby equipment, mechanical stability of test equipment, and the instruments used to measure the wire motion. Mitigations include curve fitting and adaptive noise signal cancellation, and mechanical damping. Finite Element Analysis (FEA) was used to identify and resolve a repeatable wire vibration frequency interfering with the signal resolution. Two stretched wire alignment technique set ups from Sandia National Labs and Lawrence Livermore National Lab have shown background noise sources and ways of mitigating them by either analysis methods or change of mechanical configuration. Conclusions that were drawn included the severe sensitivity of the deflection to even small external interferences of the SWAT wire such that it requires attention to detail in mechanical set up and analysis.

Linear Inductive Accelerator↗
DOE OSTI2022

Gas-mapping 3D imager measurement techniques and method of data processing

Measurement approaches and data analysis methods are disclosed for combining 3D topographic data with spatially-registered gas concentration data to increase the efficiency of gas monitoring and leak detection tasks. Here, the metric for efficiency is defined as reducing the measurement time required to achieve the detection, or non-detection, of a gas leak with a desired confidence level. Methods are presented for localizing and quantifying detected gas leaks. Particular attention is paid to the combination of 3D spatial data with path-integrated gas concentration measurements acquired using remote gas sensing technologies, as this data can be used to determine the path-averaged gas concentration between the sensor and points in the measurement scene. Path-averaged gas concentration data is useful for finding and quantifying localized regions of elevated (or anomalous) gas concentration making it ideal for a variety of applications including: oil and gas pipeline monitoring, facility leak and emissions monitoring, and environmental monitoring.

Thorpe, Michael↗
DOE OSTI2020

Preparation of 241 Am/ 243 Am gravimetric mixtures and development of Am isotopic and assay measurement techniques using thermal ionization mass spectrometry

Three gravimetric mixtures with 241 Am/ 243 Am isotope ratios at nominally 1:1, 20:1, and 200:1 were prepared for calibration of the thermal ionization mass spectrometer instruments used for americium isotopic and assay measurements by isotope dilution mass spectrometry. The total evaporation analytical technique was developed for high-accuracy and precision measurements of Am isotopic ratios. The technique was also applied to Am assay measurements using isotope dilution mass spectrometry. The Am isotope ratio and assay measurement techniques were utilized to characterize batches of americium oxide separated from plutonium materials in storage at Los Alamos National Laboratory in support of commercial use of 241 AmO 2 .

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2021

Apparatus and method for dynamic acousto-elasticity technique measurements at simulated subsurface pressures

An apparatus (10) and method for performing nonlinear elasticity measurements using the dynamic acousto-elasticity technique (DAET) at simulated subsurface conditions in the laboratory, are described. The current state-of-the-art for measuring nonlinear elasticity parameters using DAET is limited to ambient pressure conditions on the bench-top. The present invention permits nonlinear parameter measurements at controlled sample internal fluid pore pressures (52) and external confining stress (44), (50) conditions.

Roberts, Peter M.↗
DOE OSTI2021

Measurement techniques of thermoelectric devices and modules

Thermoelectric (TE) energy conversion devices are designed based on measured material transport properties. Although an ideal device efficiency can be calculated using the figure of merit, zT, the actual efficiency of a thermoelectric module is smaller and must be measured. TE device performance testing techniques and procedures are reviewed with a focus on energy conversion efficiency. One of the areas that attract less attention in the literature is the transition from basic thermoelectric materials research to the production of modules and devices. The effects of interface layers, diffusion barriers, thermal insulations, and heat sinks are reviewed. Finally, device performance from single couples to standard modules and long-term reliability are discussed.

Wang, Hsin↗
DOE OSTI2019

Status Report: Design and Fabricate Installation-Ready Test Capsule for the In-Situ Measurement of Elastic Properties Using an Optical Fiber-Based Measurement Technique

Microstructure evolution due to irradiation in a nuclear reactor can have a dramatic effect on material properties. A better understanding of this evolution is necessary for developing improved nuclear fuels and materials. The ability to measure such changes in real time is extremely limited due to the harsh conditions, high radiation fields, and limited access of the reactor environment. Through carefully designed experiments, measurement of elastic properties can be tied directly to microstructure. We present the methodology, design, and deployment plan for an instrument that has been developed to monitor grain microstructural changes during irradiation. Our measurement approach involves exciting and measuring the resonant frequency of a thin cantilever beam. Excitation and detection of the flexural vibrations of the beam are accomplished using optical methods that require only an optical fiber connection between the instrumentation and the sample. This technique has been demonstrated in a laboratory setting to monitor the recrystallization of highly textured copper during high temperature annealing. A test capsule incorporating this technique has been developed for in reactor testing. The capsule has been designed to be compatible with a reusable test module that allows simplified insertion in the TREAT reactor at INL. An exact replica of the instrument described in this Status Report, constructed from Quality Level 3 materials, is slated to be inserted into the TREAT reactor in FY19.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗
DOE OSTI2024

The Dynamic Assimilation Technique measures photosynthetic CO2 response curves with similar fidelity as steady-state approaches in half the time

The net CO2 assimilation (A) response to intercellular CO2 concentration (Ci) is a fundamental measurement in photosynthesis and plant physiology research. The conventional A/Ci protocols rely on steady-state measurements and take 15-40 minute per measurement, limiting data resolution or biological replication. Additionally, there are several CO2 protocols employed across the literature, without clear consensus as to the optimal protocol or systematic biases in their estimations. We compared the non-steady state Dynamic Assimilation Technique (DAT) protocol and the three most used CO2 protocols in steady-state measurements, and tested whether different CO2 protocols lead to systematic differences in estimations of the biochemical limitations to photosynthesis.

A/Ci response↗
DOE OSTI2024

The Dynamic Assimilation Technique measures photosynthetic CO 2 response curves with similar fidelity to steady-state approaches in half the time

The net CO 2 assimilation (A) response to intercellular CO 2 concentration (C i ) is a fundamental measurement in photosynthesis and plant physiology research. The conventional A/C i protocols rely on steady-state measurements and take 15–40 min per measurement, limiting data resolution or biological replication. Additionally, there are several CO 2 protocols employed across the literature, without clear consensus as to the optimal protocol or systematic biases in their estimations. We compared the non-steady-state Dynamic Assimilation Technique (DAT) protocol and the three most used CO 2 protocols in steady-state measurements, and tested whether different CO 2 protocols lead to systematic differences in estimations of the biochemical limitations to photosynthesis. The DAT protocol reduced the measurement time by almost half without compromising estimation accuracy or precision. The monotonic protocol was the fastest steady-state method. Estimations of biochemical limitations to photosynthesis were very consistent across all CO 2 protocols, with slight differences in Rubisco carboxylation limitation. The A/C i curves were not affected by the direction of the change of CO 2 concentration but rather the time spent under triose phosphate utilization (TPU)-limited conditions. Our results suggest that the maximum rate of Rubisco carboxylation (V cmax ), linear electron flow for NADPH supply (J), and TPU measured using different protocols within the literature are comparable, or at least not systematically different based on the measurement protocol used.

54 ENVIRONMENTAL SCIENCES↗