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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 1,063 records · Page 59
All sourcesNASA NTRSDOE OSTI
DOE OSTI2013

Precision Measurement of {eta} --> {gamma} {gamma} Decay Width via the Primakoff Effect

A precision measurement of the {eta} --> {gamma} {gamma} decay width via the Primakoff effect is underway in Hall D at Jefferson Lab. The decay width will be extracted from measured differential cross sections at forward angles on two light targets, liquid hydrogen and 4He, using a 11.5 GeV tagged photon beam. Results of this experiment will not only potentially resolve a long standing discrepancy between the Primakoff and the collider measurements, but will also reduce the experimental uncertainty by a factor of two on the average value of previous experimental results listed by the Particle Data Group(PDG). It will directly improve all other eta partial decay widths which rely on the accuracy of the eta radiative decay width. The projected 3% precision on the {Gamma}({eta} --> {gamma} {gamma} ) measurement will have a significant impact on the experimental determination of the fundamental parameters in QCD, such as the ratio of light quark masses (m{sub u},m{sub d},m{sub s}) and the {eta} - {eta}' mixing angle. It will be a sensitive probe for understanding QCD symmetries and the origin and the dynamics of QCD symmetry breaking.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2014

High-precision B(E2) measurements of semi-magic 58,60,62,64Ni by Coulomb excitation

High-precision reduced electric-quadrupole transition probabilities B(E2) have been measured from single-step Coulomb excitation of semi-magic 58,60,62,64 Ni (Z = 28) beams at 1.8 MeV per nucleon on a natural carbon target. The energy loss of the nickel beams through the carbon target were directly measured with a zero-degree Bragg detector and the absolute B(E2) values were normalized by Rutherford scattering. The B(E2) values disagree with recent lifetime studies that employed the Doppler-shift attenuation method. The present high-precision B(E2) values reveal an asymmetry about 62 Ni, midshell between N = 28 and 40, with larger values towards 56 Ni (Z = N = 28). The experimental B(E2) values are compared with shell-model calculations in the full pf model space and the results indicate a soft 56 Ni core.

Allmond, James M↗
DOE OSTI2015

Auto-calibrated scanning-angle prism-type total internal reflection microscopy for nanometer-precision axial position determination and optional variable-illumination-depth pseudo total internal reflection microscopy

A method, apparatus, and system for improved VA-TIRFM microscopy. The method comprises automatically controlled calibration of one or more laser sources by precise control of presentation of each laser relative a sample for small incremental changes of incident angle over a range of critical TIR angles. The calibration then allows precise scanning of the sample for any of those calibrated angles for higher and more accurate resolution, and better reconstruction of the scans for super resolution reconstruction of the sample. Optionally the system can be controlled for incident angles of the excitation laser at sub-critical angles for pseudo TIRFM. Optionally both above-critical angle and sub critical angle measurements can be accomplished with the same system.

36 MATERIALS SCIENCE↗
DOE OSTI2017

High precision detector robot arm system

A method and high precision robot arm system are provided, for example, for X-ray nanodiffraction with an X-ray nanoprobe. The robot arm system includes duo-vertical-stages and a kinematic linkage system. A two-dimensional (2D) vertical plane ultra-precision robot arm supporting an X-ray detector provides positioning and manipulating of the X-ray detector. A vertical support for the 2D vertical plane robot arm includes spaced apart rails respectively engaging a first bearing structure and a second bearing structure carried by the 2D vertical plane robot arm.

42 ENGINEERING↗
DOE OSTI2014

Precision circuit calculations in hostile environments.

Sensing and calculating electronic systems with stringent accuracy requirements use internal standard voltages for references. Conceptually, this is related to using some unit measurement for counting any quantity. The high precision electronic components used in systems in the nation’s stockpile also make use of these standard voltages. The need for stable voltage references has been long-standing in the overall electronics industry. For many applications, the most pressing need is for stability of a reference voltage as the circuit temperature varies. Typical circuit components have temperature coefficients for their operational characteristics that are given in some delta per degree centigrade and these coefficients can be either positive or negative. Thus, it is natural to consider building a circuit out of components that have complementary temperature coefficients so that the operating characteristics of the circuit have a net zero temperature coefficient. This is the fundamental basis of precision voltage reference (PVR) circuit operation and it is straightforward to extend this type of stabilization to reduce shifts caused by hostile environment radiation.

42 ENGINEERING↗
DOE OSTI2018

Hardware accuracy counters for application precision and quality feedback

Methods, devices, and systems for capturing an accuracy of an instruction executing on a processor. An instruction may be executed on the processor, and the accuracy of the instruction may be captured using a hardware counter circuit. The accuracy of the instruction may be captured by analyzing bits of at least one value of the instruction to determine a minimum or maximum precision datatype for representing the field, and determining whether to adjust a value of the hardware counter circuit accordingly. The representation may be output to a debugger or logfile for use by a developer, or may be output to a runtime or virtual machine to automatically adjust instruction precision or gating of portions of the processor datapath.

47 OTHER INSTRUMENTATION↗
DOE OSTI2020

Method and precision nanopositioning apparatus with compact vertical and horizontal linear nanopositioning flexure stages for implementing enhanced nanopositioning performance

An enhanced method and precision nanopositioning apparatus for implementing enhanced nanopositioning performance is provided. The nanopositioning apparatus includes a vertical linear nanopositioning flexure stage and a horizontal linear nanopositioning flexure stage. The vertical linear nanopositioning flexure stage includes a stage base, a symmetrically configured flexure linear guiding mechanism with precision motion enhancement structure, and a stage carriage. The horizontal linear nanopositioning flexure stage is mounted on the stage carriage of the vertical linear nanopositioning flexure stage, and includes a middle-bar relative position control mechanism to enhance the stiffness of a flexure linear guiding mechanism.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2020

A High Precision Measurement of the Proton Charge Radius at JLab

The elastic electron-proton (e-p) scattering and the spectroscopy of hydrogen atoms are the two traditional methods to determine the proton charge radius (r p ). In 2010, a new method using muonic hydrogen (µH) 1 spectroscopy reported a r p result that was nearly ten times more precise but significantly smaller than the values from the compilation of all previous r p measurements. This discrepancy is often referred to as the "proton charge radius puzzle". In order to investigate the puzzle, the PRad experiment (E12-11-106) was first proposed in 2011 and performed in 2016 in Hall B at the Thomas Jefferson National Accelerator Facility, with both 1.1 and 2.2 GeV electron beams. The experiment measured the e-p elastic scattering cross sections in an unprecedented low values of momentum transfer squared region (Q 2 = 2.1× 10 -4 -0.06 (GeV/c) 2 ), with a sub-percent precision. The PRad experiment utilized a calorimetric method that was magnetic-spectrometer-free. Its detector setup included a large acceptance and high resolution calorimeter (HyCal), and two large-area, high spatial-resolution Gas Electron Multiplier (GEM) detectors. To have a better control over the systematic uncertainties, the absolute e-p elastic scattering cross section was normalized to that of the well-known Møller scattering process, which was measured simultaneously during the experiment. For each beam energy, all data with different Q 2 were collected simultaneously with the same detector setup, therefore sharing the same integrated luminosity. The windowless H 2 gas-flow target utilized in the experiment largely removed a typical background source, the target cell windows. The proton charge radius was determined as r p = 0.831±0.007 stat. ±0.012 p fm, which is smaller than the average r p from previous e-p elastic scattering experiments, but in agreement with the µH spectroscopic results within the experimental uncertainties.

Source record↗
DOE OSTI2021

Methods for Precision Studies of Neutrino Interactions

Accelerator neutrino oscillation experiments provide a sensitive way to investigatea number of major open questions in neutrino physics. To achieve precision neutrinooscillation measurements, we need a good understanding of key aspects of the experiments,such as the detection technologies used and neutrino interactions at few-GeV energies.The MicroBooNE experiment has advanced the development of technologies for LArTPCs.An ultra-violet laser system was introduced to MicroBooNE in order to measure theelectric field in situ, which plays a central role in the formation of charge and lightsignals in LArTPCs. This thesis describes the setup and operation of the laser system. Ideveloped a general methodology to measure the electric field and the consequent spatialdistortion in LArTPCs, which supports precision measurements in accelerator neutrinooscillation experiments. In MicroBooNE, the measured electric field distortions are upto 15 ± 3 % with respect to the nominal value, and the measured spatial distortions areup to 15 ± 3 cm. The result of the electric field measurement is applied to the detectorsimulation and the event reconstruction, which leads to a better detector characterizationfor neutrino analyses. A significant concern for measurements of neutrino interactions ismodel dependence, as the currently available models are not sufficient for describing thepicture of neutrino interacting at few-GeV energies. In this thesis, I developed a detailedstrategy for a model-independent cross-section measurement at low energy transfers,where the available model predictions do not agree with the inclusive measurementsfrom multiple experiments. A likelihood fit technique for cross-section extraction isrealized in an accelerator neutrino experiment using a LArTPC for the first time. Thetreatment of systematic uncertainties developed in this thesis is generally applicable foranalyses using similar fitting techniques. This neutrino interaction study at low energytransfers provides a probe to the poorly understood region of neutrino cross sections. Themeasurement scheme developed here aims to guide future model-independent cross-sectionmeasurements, particularly for neutrino experiments using LArTPCs.

Chen, Yifan↗
DOE OSTI2021

Precision cooking system

The present invention comprises a precision cooking oven that utilizes laser sheets to cook food, thus creating homogeneously heated and uniformly seared food bodies and surfaces. Laser sheets move back and forth evenly injecting heat into items being cooked. All food cold or hot areas can be eliminated since intersecting laser lines can be completely projected on and accommodate an item's exterior surfaces. Items with non-uniform cross-sections and properties can be cooked uniformly by controlling the exact amount of energy projected into differing sections of the food. The oven is also capable of cooking autonomously. Since laser sheets can be precisely controlled, cooking results can be very predictable once the boundary conditions for a thermal analysis are determined. The oven can detect the properties of the items to be cooked and thereafter compute the needed time and power to achieve the desired results stipulated by an oven operator.

Lee, Henry Yu-Heng↗
DOE OSTI2011

Qweak: A Precision Standard Model Test at Jefferson Lab

The Qweak collaboration is currently performing the first precision measurement of the proton's neutral weak charge at Jefferson Lab. The Standard Model gives a firm prediction for the weak charge; any deviation from that can be interpreted as new physics beyond the Standard Model. This precision, low energy measurement is sensitive to new physics signatures at energy scales up to 2 TeV. The experiment measures the parity-violating asymmetry in the scattering of longitudinally polarized electrons on the proton at low momentum transfer. An overview of the motivation and experimental approach will be presented, along with an update on the current status.

Pitt, Mark↗
DOE OSTI2023

Precise Measurement of the Neutron Skin Thicknesses of 208Pb and 48Ca

Despite great leaps of development in nuclear physics over the past century, we still do not have a comprehensive understanding of nuclear structure. This is mainly due to the lack of precise knowledge of the neutron distribution inside nucleus. Electromagnetic probes are ineffective in probing neutrons, unlike their charged partners, the protons. Therefore, it is of great importance to constrain the neutron distributions experimentally. Heavy nuclei have more neutrons than protons in order to balance the repulsion between protons. In such neutron-rich nuclei, the extra neutrons are pushed out to the surface by the nuclear symmetry energy, forming the so-called ?neutron skin?. The neutron skin can be probed with a well-established experimental technique ? parity-violating electron scattering (PVES). Using the scattering of longitudinally polarized electrons by an unpolarized target, PREX-II and CREX measure the small parity-violating asymmetry in cross sections. Employing electrons with opposite helicities the weak form factor, the neutron distribution and the neutron skin thickness of the target nucleus are extracted. With excellent beam qualities and dedicated instrumentation at Jefferson Lab, the asymmetry measurements are statistics-limited. We report the results of these two high-precision measurements and their implications on broad topics, from the nuclear structures to the neutron stars.

Zhang, Weibin↗
DOE OSTI2022

Report of the Topical Group on Higgs Physics for Snowmass 2021: The Case for Precision Higgs Physics

A future Higgs Factory will provide improved precision on measurements of Higgs couplings beyond those obtained by the LHC, and will enable a broad range of investigations across the fields of fundamental physics, including the mechanism of electroweak symmetry breaking, the origin of the masses and mixing of fundamental particles, the predominance of matter over antimatter, and the nature of dark matter. Future colliders will measure Higgs couplings to a few per cent, giving a window to beyond the Standard Model (BSM) physics in the 1-10 TeV range. In addition, they will make precise measurements of the Higgs width, and characterize the Higgs self-coupling. Here, this report details the work of the EF01 and EF02 working groups for the Snowmass 2021 study.

Dawson, Sally↗
DOE OSTI2015

Application of the FW-CADIS variance reduction method to calculate a precise N-flux distribution for the FRJ-2 research reactor - 15603

In order to avoid unnecessary radiation exposure and to minimize the radioactive waste and respectively cost by the decommissioning of nuclear facilities, the radiological characteristics and the activity atlases are required. Therefore, a significant step is the accurate determination of the neutron fluence distribution resulting from the operation of a reactor. For this purpose, computer codes based on the Monte-Carlo method are employed because of the flexibility in the modelling of the complex structures and physical processes. In the scope of the research project founded by the German Federal Ministry of Education and Research (BMBF), and implemented by the Institute of Nuclear Engineering and Technology Transfer (NET) -RWTH Aachen, sophisticated simulation tools are developed, which have the capability to cover the range of demands for activity and dose rate distribution using the example of the German research reactor FRJ-2. Due to the complex geometry of FRJ-2, which consists of different structures and configuration, the MCNP5 Monte Carlo Code is the optimal method for a precise neutron transport simulation. This work presents a method to achieve a precise N-Flux distribution for the FRJ-2 research reactor using hybrid deterministic Monte Carlo method. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2019

High Precision In-Pipe Robot Localization with Reciprocal Sensor Fusion - 19516

Manual measurement of U-235 deposits in uranium enrichment piping is a costly, time consuming, and labor-intensive process that is a well-known cost and schedule driver. Autonomous, robotic innovation enabled by this research is revolutionizing the measurement speed, quality and safety of this important operation. The huge advantage is the robot's ability to measure from inside the pipes. The upside is sensing the geometry, appearance and radiometry directly. The downside is the inability to know precise, absolute position of the measurements in very long pipe runs. This paper develops the unprecedented localization required for this purpose. This paper presents the precise localization method designed for in-pipe radiation measurement robots. Unlike other in-pipe localization methods, this approach achieves millimeter-level accuracy in hundred-foot runs and does everything on one robot without relying on tether cable or communicating devices out of pipe, which is an important feature for nuclear in-pipe robot. It overcomes challenges usually encountered by in-pipe localization such as long travelling distance and operation time, narrow view angle, and featureless environment. The robot is equipped with encoders embedded in tracks which can record travelled distance, but encoder odometry drifts unacceptably due to slip and non-linearity. The robot also incorporates a laser range finder measuring the absolute distance, but range finder in long pipes has many misleading false measurements that are difficult to filter. The innovation here is to use one to filter/calibrate the other so that data used from the two sensors improve each other iteratively and reciprocally. The survey measurements accuracy of this localization method is proven by experiments comparing to ground truth and 'Zippering error' experiments that compare measurements to fixed features in pipes. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2014

Validation of a Monte Carlo model for the MLC-Elekta Precise with MCNP6 - Paper 76

Cancer treatment using radiotherapy techniques needs an accurate prediction of the dose delivered to the patient at each position. Treatment planning systems (TPS) allow the optimization of the dose delivered to the tumor volume while minimizing the dose absorbed by the surrounding healthy tissue. Commercial treatment planning systems use empirical deterministic algorithms that do not correctly estimate the dose in the surroundings of heterogeneities. This lack of accuracy is taken into account as bigger security margins in the treatment, reducing the potential effect of the treatment. However, Monte Carlo (MC) simulation techniques have proved to predict the dose distribution more accurately and also representing experimental data better. Nevertheless, the clinical application of these techniques has been limited by the long calculation times they require. As high performance computers decrease in cost MC simulations become more feasible to be used in TPS. The present work improves a simplified model of the MLC-Elekta Precise linear accelerator (linac or unit from now on) previously developed and correctly validated by the group. A multileaf collimator (MLC) has been modelled according to the manufacturer specifications and added to the previous model to allow higher conformity in the studies. The full geometry has been entered to the MCNP6 Monte Carlo code to simulate the transport of particles through the linac. The geometry also includes a cubic water phantom for dosimetry studies and validation with experimental data. The experimental data employed for the dose distribution comparison has been measured at the linac from the linac Hospital Universitari Clinic de Valencia (Spain). Additionally, particles are stored in a phase space surface before their entrance in the water to be analyzed and for performance optimization. Given the results presented, we conclude that this first approach to validate a model of the Elekta Precise linac from the Hospital Cl nic Universitari de Valancia represents well the depth-dose distribution, but fails at representing the dose profiles. It has been shown that they predict too much penumbra, probably caused by the filtration between the leaves. In order to solve this problems, further work is needed to improve the simulated model. This work will mainly focus on the multileaf collimator. Also, the codes developed by the group to analyze phase space files produced by MCNP6 have proven highly useful. As work progress and the codes are debugged, they will be published so that the community can take advantage of them.

61 RADIATION PROTECTION AND DOSIMETRY↗
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↗
DOE OSTI2024

Perspectives for Measuring Neutrino Cross-Sections at Short Baseline Detectors (ICARUS and DUNE-PRISM-like Detector) and Their Implications for Precision Physics

Neutrino physics is rapidly advancing with current and future experiments promising high-statistics data, enabling unprecedented accuracy in measuring Standard Model (SM) parameters and providing crucial insights into neutrino-nucleus interactions. The ICARUS experiment, utilizing LAr TPC technology, is pivotal in this growth. As the far detector of the SBN program at Fermilab, ICARUS is set to investigate the neutrino anomalies observed in LSND and MiniBooNE and prepare for future long-baseline experiments like DUNE. Positioned along the BNB and 5.75°off-axis from the NuMI beamline, ICARUS benefits from numerous neutrino interactions, allowing for precise neutrino-argon nucleus cross-section measurements, which will benchmark future DUNE measurements. This work presents the prospects and progress in measuring the cross-section of the NuMI νµ CC inclusive channel in the ICARUS experiment. High-statistics data will also enable precise determinations of fundamental parameters like the weak mixing angle and the neutrino charge radius (NCR), crucial for testing the SM and exploring potential new physics. This work includes studies of future near detectors, such as DUNE-PRISM, which are sensitive to radiative corrections in neutrino-electron scattering. The DUNE-PRISM configuration allows for the analysis of different neutrino energy spectra, promising accurate NCR measurements with controlled systematic uncertainties.

Moreno-Granados, Guadalupe↗