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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 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
NASA NTRS2003

Precise Measurement for Manufacturing

A metrology instrument known as PhaseCam supports a wide range of applications, from testing large optics to controlling factory production processes. This dynamic interferometer system enables precise measurement of three-dimensional surfaces in the manufacturing industry, delivering speed and high-resolution accuracy in even the most challenging environments.Compact and reliable, PhaseCam enables users to make interferometric measurements right on the factory floor. The system can be configured for many different applications, including mirror phasing, vacuum/cryogenic testing, motion/modal analysis, and flow visualization.

Source record↗
DOE OSTI2025

High-precision Measurement of the 16 O($n, n'γ$) Cross Section using $γ$-ray Detection in Liquid Scintillators with H 2 O and BeO Targets

The 16 O($n, n'γ$) reaction was measured at the Los Alamos Neutron Science Center white neutron source using γ-ray detection in liquid scintillators present in the upper hemisphere of the Correlated Gamma-Neutron Array for sCattering (CoGNAC). Separate measurements of this reaction were performed using H 2 O and BeO targets in successive years. The unique high energies of γ rays emitted from the 16 O($n, n'γ$) reaction facilitated a clean selection of this reaction from threshold to 9.8 MeV incident neutron energy without the need for precise measurements of the γ-ray energy or the scattered neutrons. The precise time resolution of the liquid scintillator detectors was then exploited to obtain high-resolution incident neutron energy measurements, and good agreement was obtained between the H 2 O and BeO results reported here. The dominant literature data sets for this reaction have systematic differences between them, but the present results improve upon the neutron energy resolution of earlier measurements and show important discrepancies in recent data. Finally, tentative data are also shown up to 20 MeV incident neutron energy but are potentially subject to improved understanding of the relative γ-ray and α decay branches from 16 O excited states.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2026

Bayesian Inference of Hybrid Star Properties from Future High-precision Measurements of Their Radii

Future high-precision X-ray and gravitational-wave observations of neutron stars (NSs) are expected to constrain NS radii with uncertainties as small as σ ≃ 0.1 km. Such unprecedented precision offers a unique opportunity to extract new information about the nature and equation of state (EOS) of supradense matter in NS cores. Using mock radius data with uncertainties ranging from σ = 1.0 to 0.1 km, together with a flexible meta-model NS EOS that allows for a first-order hadron–quark phase transition, we perform a Bayesian statistical analysis to assess the impact of radius measurements on EOS constraints. We find that high-precision radius measurements, particularly for massive NSs, significantly tighten constraints on the hadron–quark transition density ρ t , the quark matter mass fraction in NS cores, and several parameters characterizing the EOS of supranuclear hadronic matter, although the degree of improvement depends on the assumed prior range of ρ t . In contrast, even with the highest precision considered, NS radii—including those of massive stars—remain largely insensitive to the stiffness of quark matter, independent of the measurement accuracy or the prior range adopted for ρ t .

Neutron stars↗
NASA NTRS2003

Progress on Passive Sensor for Ultra-Precise Measurement of C02

We will present results from a novel instrument employing a Fabry-Perot interferometer to measure column carbon dioxide with great precision. These measurements are very important for improving our understanding of the global warming phenomenon. The instrument technique can be extended to a number of other important trace gases in the atmosphere.

Heaps, William S.↗
DOE OSTI2021

Precision measurement of the electron energy-loss function in tritium and deuterium gas for the KATRIN experiment

Abstract The KATRIN experiment is designed for a direct and model-independent determination of the effective electron anti-neutrino mass via a high-precision measurement of the tritium $$\upbeta $$ β -decay endpoint region with a sensitivity on $$m_\nu $$ m ν of 0.2 $$\hbox {eV}/\hbox {c}^2$$ eV / c 2 (90% CL). For this purpose, the $$\upbeta $$ β -electrons from a high-luminosity windowless gaseous tritium source traversing an electrostatic retarding spectrometer are counted to obtain an integral spectrum around the endpoint energy of 18.6 keV. A dominant systematic effect of the response of the experimental setup is the energy loss of $$\upbeta $$ β -electrons from elastic and inelastic scattering off tritium molecules within the source. We determined the energy-loss function in-situ with a pulsed angular-selective and monoenergetic photoelectron source at various tritium-source densities. The data was recorded in integral and differential modes; the latter was achieved by using a novel time-of-flight technique. We developed a semi-empirical parametrization for the energy-loss function for the scattering of 18.6-keV electrons from hydrogen isotopologs. This model was fit to measurement data with a 95% $$\hbox {T}_2$$ T 2 gas mixture at 30 K, as used in the first KATRIN neutrino-mass analyses, as well as a $$\hbox {D}_2$$ D 2 gas mixture of 96% purity used in KATRIN commissioning runs. The achieved precision on the energy-loss function has abated the corresponding uncertainty of $$\sigma (m_\nu ^2)< {{10}^{-2}}{\hbox {eV}^{2}}$$ σ ( m ν 2 ) < 10 - 2 eV 2 [1] in the KATRIN neutrino-mass measurement to a subdominant level.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2024

Precise Measurement of the Neutron Magnetic Form Factor Using Super-BigBite Spectrometer at Jefferson Lab

The GMn experiment (E12-09-019) was conducted at Jefferson Laboratory from late 2021 into early 2022. The goal was to make high-precision measurement of the neutron’s magnetic form factor (GMn) at multiple kinematic points, including Q2 = 3.5, 4.5, 6.5, 8.5, 10, 12, 13.5, 16, and 18 (GeV/c)2. Limited data exist for GMn in the region up to about Q2 = 10 (GeV/c)2, with existing data having large systematic uncertainty. In this experiment, the ratio method was employed to reduce systematic uncertainty by measuring the ratio of neutron and proton yields. The experiment took place at Jefferson Laboratory in Hall A, where the BigBite spectrometer was used to detect the scattered electrons, while the HCal in the SuperBigbite spectrometer was used to detect both neutrons and protons. The protons were deflected slightly upwards with the use of a large-aperture dipole magnet named BigBen, allowing for enhanced particle identification. Extraction of GMn requires taking the ratio of proton and neutron yields. Analysis efforts are still currently underway to refine corrections to the data, including detector efficiencies, radiative corrections, neutron and proton mass identification, and charge exchange.

Lashley-Colthirst, Nathaniel↗
DOE OSTI2020

Precision measurement of the neutral pion lifetime

The explicit breaking of the axial symmetry by quantum fluctuations gives rise to the so-called axial anomaly. This phenomenon is solely responsible for the decay of the neutral pion π0 into two photons (γγ), leading to its unusually short lifetime. Here, we precisely measured the decay width Γ of the π 0 → γγ process. The differential cross sections for π0 photoproduction at forward angles were measured on two targets, carbon-12 and silicon-28, yielding Γ(π 0 → γγ)=7.798±0.056(stat.)±0.109(syst.) eV, where stat. denotes the statistical uncertainty and syst. the systematic uncertainty. We combined the results of this and an earlier experiment to generate a weighted average of Γ(π 0 → γγ)=7.802±0.052(stat.)±0.105(syst.) eV. Our final result has a total uncertainty of 1.50% and confirms the prediction based on the chiral anomaly in quantum chromodynamics.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2024

Precise Measurement of the e + e − → D s + D s − Cross Section at Center-of-Mass Energies from Threshold to 4.95 GeV

Using the e + e − collision data collected with the BESIII detector operating at the BEPCII collider, at center-of-mass energies from the threshold to 4.95 GeV, we present precise measurements of the cross section for the process e + e − → D s + D s − using a single-tag method. The resulting cross section line shape exhibits several new structures, thereby offering an input for a future coupled-channel analysis and model tests, which are critical to understand vector charmonium-like states with masses between 4 and 5 GeV. Published by the American Physical Society 2024

Ablikim, M.↗
NASA NTRS2008

Precision Measurement of Black Hole Binary Dynamics: Analyzing the LISA Data Stream

One of the richest potential sources of insight into fundamental physics that LISA will be capable of observing is the inspiral of supermassive black hole binaries (BHBs). However, the data analysis challenge presented by the LISA data stream is quite unlike the situation for present day gravitational wave detectors. In order to make the precision measurements necessary to achieve LISA's science goals, the BHB signal must be distinguished from a data stream that not only contains instrumental noise, but potentially thousands of other signals as well, so that the "background" we wish to separate out to focus on the BHB signal is likely to be highly nonstationary and nongaussian, as well as being of scientific interest in its own right. In addition, whereas the theoretical templates that we calculate in order to ultimately estimate the parameters can afford to be somewhat inaccurate and still be effective for present day and near future detectors, this is not the case for LISA, and extremely high fidelity of the theoretical templates for high signal-to-noise signals will be required to prevent theoretical errors from dominating the parameter estimates. NVe, will describe efforts in the community of LISA data analysts to address the challenges regarding the specific issue of BHB signals. These efforts include using a Markov Chain Monte Carlo approach with the freedom to model the BHB and the other signals present in the data stream simultaneously, rather than trying to remove other signals and risk biasing the remaining data. The Mock LISA Data Challenge is a community of LISA scientists who generate rounds of simulated LISA noise with increasingly difficult signal content, and invite the LISA data analysis community to exercise their methods, or develop new methods, in an attempt to extract the parameters for the signals embedded in the mock data. In addition to practical approaches such ,is this to assess the level of parameter accuracy, one can apply the Fisher matrix formalism to assess both the statistical errors from noise and the theoretical errors

McWilliams, Sean T.↗
DOE OSTI2022

Precision measurement of Compton scattering in silicon with a skipper CCD for dark matter detection

Experiments aiming to directly detect dark matter through particle recoils can achieve energy thresholds of $\mathcal{O}(1\,\mathrm{eV})$. In this regime, ionization signals from small-angle Compton scatters of environmental $\gamma$-rays constitute a significant background. Monte Carlo simulations used to build background models have not been experimentally validated at these low energies. We report a precision measurement of Compton scattering on silicon atomic shell electrons down to 23$\,$eV. A skipper charge-coupled device (CCD) with single-electron resolution, developed for the DAMIC-M experiment, was exposed to a $^{241}$Am $\gamma$-ray source over several months. Features associated with the silicon K, L$_{1}$, and L$_{2,3}$-shells are clearly identified, and scattering on valence electrons is detected for the first time below 100$\,$eV. We find that the relativistic impulse approximation for Compton scattering, which is implemented in Monte Carlo simulations commonly used by direct detection experiments, does not reproduce the measured spectrum below 0.5$\,$keV. The data are in better agreement with $ab$$initio$ calculations originally developed for X-ray absorption spectroscopy.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2022

Charge Symmetry Violation Quark Distributions Via Precise Measurement of p+/p- Rations in Semi-Inclusive Deep Inelastic Scattering

Charge symmetry in the nucleon parton distributions assumes the distribution of quarks in the proton is related to those in the neutron. Indirect experimental evidence constrains Charge Symmetry Violation (CSV) to be less than 9%. In Quantum Chromo-Dynamics (QCD), charge symmetry is broken by the mass difference between the up and down quarks. CSV in the valence region can be extracted from precision measurements of the cross section ratio of charged pion production in semi-inclusive deep inelastic scattering (SIDIS) from deuterium. Such measurements were proposed and carried out in experiment E12-09-002 at Jefferson Lab. The experiment was conducted in Hall C from fall 2018 to spring 2019 using the upgraded 10.6 GeV incident electron beam. In this SIDIS experiment, charged pions are detected in coincidence with scattered electrons covering the four-momentum transfer of the virtual photon Q2 from 4 to 5.5 GeV2, the Bjorken variable x for 0.35-0.65, and the fraction of energy transfer carried by the outgoing pion z from 0.4-0.7.

Jia, Shuo↗
DOE OSTI2022

Ferrite-Free Circulator for Precise Measurements of SRF Cavities with High Q-Factor

In this work, we suggest and investigate new magnetless circulators based on three resonators connected in a loop and parametrically modulated in time with mutual phase lag. The first design consists of three Fano resonators with a spectrally asymmetric response, in contrast to schemes based on the Lorentz resonators explored thus far. The second design includes three Fano-Lorentz resonators, i.e., it also possesses spatial asymmetry. We demonstrate that the asymmetric approach provides strong and reversible isolation for the practically feasible modulation amplitude and rate. The results of our work are promising for precise measurements of superconducting radio frequency cavities with high Q-factor.

43 PARTICLE ACCELERATORS↗
NASA NTRS2005

Development of a Fabry-Perot Interferometer for Ultra-Precise Measurements of Column CO2

A passive Fabry-Perot based instrument is described for detecting column CO2 through absorption measurements at 1.58 microns . In this design, solar flux reaches the instrument platform and is directed through two channels. In the first channel, transmittance fi5nges from a Fabry-Perot interferometer are aligned with CO2 absorption lines so that absorption due to CO2 is primarily detected. The second channel encompasses the same frequency region as the first, but is comparatively more sensitive to changes in the solar flux than absorption due to CO2. The ratio of these channels is sensitive to changes in the total CO2 column, but not to changes in solar flux. This inexpensive instrument will offer high precision measurements (error 4%) in a compact package. Design of this instrument and preliminary ground-based measurements of column CO2 are presented here as well as strategies for deployment on aircraft and satellite platforms.

Wilson, Emily L.↗
NASA NTRS2012

Development of Metallic Magnetic Calorimeters for High Precision Measurements of Calorimetric Re-187 and Ho-163 Spectra

The measurement of calorimetric spectra following atomic weak decays, beta (b) and electron capture (EC), of nuclides having a very low Q-value, can provide an impressively high sensitivity to a non-vanishing neutrino mass. The achievable sensitivity in this kind of experiments is directly connected to the performance of the used detectors. In particular an energy resolution of a few eV and a pulse formation time well below 1 microsecond are required. Low temperature Metallic Magnetic Calorimeters (MMCs) for soft X-rays have already shown an energy resolution of 2.0 eV FWHM and a pulse rise-time of about 90 ns for fully micro-fabricated detectors. We present the use of MMCs for high precision measurements of calorimetric spectra following the beta-decay of Re-187 and the EC of Ho-163. We show results obtained with detectors optimized for Re-187 and for Ho-163 experiments respectively. While the detectors equipped with superconducting Re absorbers have not yet reached the aimed performance, a first detector prototype with a Au absorber having implanted Ho-163 ions already shows excellent results. An energy resolution of 12 eV FWHM and a rise time of 90 ns were measured.

Ranitzsch, P. C.-O.↗
DOE OSTI2024

High precision measurements of α 𝑠 at the future EIC

Here, we present a projection study for the first moments of the inclusive spin structure function ∫𝑔 1 ⁡(𝑥,𝑄 2 )𝑑𝑥 for the proton and neutron from simulated doubly-polarized $\overrightarrow{e}$ $⁢\overrightarrow{p}$ and $\overrightarrow{e}$ − $\overrightarrow{^{3}He}$ collision data expected from the Electron Ion Collider. For detection and extraction of the neutron spin asymmetries from $\overrightarrow{e}$ − $\overrightarrow{^{3}He}$ collisions, we used the double-tagging method which significantly reduces the uncertainty over the traditional inclusive method. Using the Bjorken Sum Rule, the projected results allow us to determine that the QCD coupling at the 𝑍-pole 𝛼 𝑠 ⁡(𝑀$^2_{Z^0}$) can be measured with a relative precision of 1.3%. This underscores the significance of the EIC for achieving precision determinations of 𝛼 𝑠 .

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2025

Precision measurement of the B0 meson lifetime using B0→J/ψK∗0 decays with the ATLAS detector

A measurement of the B0$$B^{0}$$ meson lifetime using B0→J/ψK∗0$$ B^{0} \rightarrow J/\psi K^{*0} $$ decays in data from 13 TeV$$\text {TeV}$$ proton–proton collisions with an integrated luminosity of 140fb-1$$ 140~\mathrm {fb^{-1}} $$ recorded by the ATLAS detector at the LHC is presented. The measured effective lifetime is τ=1.5053±0.0012(stat.)±0.0035(syst.)ps.$$ \tau = 1.5053\pm 0.0012~\mathrm {(stat.)} \pm 0.0035~\mathrm {(syst.)~ps}. $$The average decay width extracted from the effective lifetime, using parameters from external sources, is Γd=0.6639±0.0005(stat.)±0.0016(syst.)±0.0038(ext.)ps-1,$$\begin{aligned} \Gamma _d = 0.6639\pm 0.0005~\mathrm {(stat.)} \pm 0.0016~\mathrm {(syst.)}\\ \pm 0.0038~\text {(ext.)} \text {~ps}^{-1}, \end{aligned}$$where the uncertainties are statistical, systematic and from external sources. The earlier ATLAS measurement of Γs$$\Gamma _s$$ in the Bs0→J/ψϕ$$B^{0}_{s} \rightarrow J/\psi \phi $$ decay was used to derive a value for the ratio of the average decay widths Γd$$\Gamma _d$$ and Γs$$\Gamma _s$$ for B0$$B^{0} $$ and Bs0$$B^{0}_{s} $$ mesons respectively, of ΓdΓs=0.9905±0.0022(stat.)±0.0036(syst.)±0.0057(ext.).$$ \frac{\Gamma _d }{\Gamma _s } = 0.9905\pm 0.0022~\text {(stat.)} \pm 0.0036~\text {(syst.)} \pm 0.0057~\text {(ext.)}. $$The measured lifetime, average decay width and decay width ratio are in agreement with theoretical predictions and with measurements by other experiments. This measurement provides the most precise result of the effective lifetime of the B0$$B^{0}$$ meson to date.

Aad, G↗
DOE OSTI2024

The precision measurement of the muon $g-2$ at Fermilab

The Muon $g-2$ Experiment at Fermilab aims to measure the magnetic anomaly of the muon with the unprecedented precision of 140 parts per billion. In April 2021, the collaboration published the first measurement based on the first year of data collection, which was found to be consistent with the previous experiment at Brookhaven. The new global average of the experimental measurements strengthens the long-standing tension with the data-driven Standard Model prediction to a combined discrepancy of 4.2$\sigma$. On the theory side, however, recent improvements in the theoretical calculation of the hadronic contribution based on Lattice-QCD techniques are introducing new tensions on the value predicted by the theory. The Muon $g-2$ Experiment at Fermilab has now concluded its sixth and final year of data taking and a new result based on the Run-2 and Run-3 data was published in August 2023. This paper briefly describes the precision measurement conducted by the Muon $g-2$ Experiment at Fermilab and its current status.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
NASA NTRS2005

Prospects for Precision Measurement of CO2 Column from Space

In order to address the problem of sources and sinks of CO2 measurements are needed on a global scale. Clearly a satellite is a promising approach to meeting this requirement. Unfortunately, most methods for making a CO2 measurement from space involve the whole column. Since sources and sinks at the surface represent a small perturbation to the total column one is faced with the need to measure the column with a precision better than 1%. No species has ever been measured from space at this level. We have developed over the last 3 years a small instrument based upon a Fabry-Perot interferometer that is very sensitive to atmospheric CO2 and has a high signal to noise ratio. We have tested this instrument in a ground based configuration and from aircraft platforms simulating operation from a satellite. We will present results from these tests and discuss ways that this promising new instrument could be used to improve our understanding of the global carbon budget.

Heaps, William S.↗