Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Resonators”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 703 records · Page 39

Phonon Transport Controlled by Ferromagnetic Resonance

The resonant coupling of phonons and magnons is important for the interconversion of phononic and spin degrees of freedom. We study the phonon transmission in LiNbO 3 manipulated by the dynamic magnetization in a Ni thin film. It is observed that the phonons can be absorbed strongly through resonant magnon-phonon coupling, which is realized by our modifying the magnon-phonon coupling within the Ni itself as well as our optimizing the interfacial coupling between Ni and LiNbO 3 . The line shapes of phonon transmission are further investigated considering the magnon-phonon interconversion in the elastically driven ferromagnetic resonance process. The results promote unique routes for phonon manipulation and detection in the presence of magnetization dynamics.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

High-Cooperativity Coupling of Rare-Earth Spins to a Planar Superconducting Resonator

The interfacing of a superconducting microwave resonator with rare-earth-doped crystals presents a promising hybrid quantum system for applications including spin-assisted transducers and memories. The coupling strength between the spins of the rare-earth ions and the microwave photons is characterized by the cooperativity. Here, we report an ultrahigh cooperativity of C~650 between rare-earth spins and a planar superconducting microwave resonator that features a highly uniform magnetic field for harnessing the strong anisotropic coupling strength of erbium-doped yttrium orthosilicate. This cooperativity rivals that from a bulk dielectric resonator and may pave a path for efficient coupling of spins with microwave photons on an integrated platform.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Zero-field spin resonance in graphene with proximity-induced spin-orbit coupling

In this work we investigate collective spin excitations in graphene with proximity-induced spin-orbit coupling (SOC) of the Rashba and valley-Zeeman types, as it is the case, e.g., for graphene on transition-metal-dichalcogenide substrates. It is shown that, even in the absence of an external magnetic field, such a system supports collective spin modes, which correspond to coupled oscillations of the uniform and valley-staggered magnetizations. These modes can be detected via both zero-field electron spin resonance (ESR) and zero-field electric-dipole spin resonance (EDSR), with EDSR response arising solely due to Rashba SOC. We analyze the effect of electron-electron interaction within the Fermi-liquid kinetic equation and show that the interaction splits both the ESR and EDSR peaks into two. The magnitude of splitting and the relative weights of the resonances can be used to extract the spin-orbit coupling constants and many-body interaction parameters that may not be accessible by other methods.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Exclusive π 0 p electroproduction off protons in the resonance region at photon virtualities 0.4 GeV 2 ≤ Q 2 ≤ 1 GeV 2

The limited electroproduction process e p → e ' p ' π 0 was measured in the range of photon virtualities Q 2 = 0.4 – 1.0 GeV 2 and the invariant mass range of the p π 0 system of W = 1.1 – 1.8 GeV. These kinematics are covered in exclusive π 0 electroproduction off the proton with nearly complete angular coverage in the p π 0 center-of-mass system and with high statistical accuracy. Nearly 36 000 cross-section points were measured, and the structure functions σ T + ε σ L , σ L T , and σ T T , were extracted via fitting the φ π 0 dependence of the cross section. A Legendre polynomial expansion analysis demonstrates the sensitivity of our data to high-lying N * and Δ * resonances with M > 1.6 GeV. As part of a broad effort to determine the electrocouplings of the N * and Δ * resonances using both single- and double-pion electroproduction, this dataset is key for the reliable extraction of the high-lying resonance electrocouplings from the combined isospin analysis of the N π and π + π - p channels.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Reexamination of isoscalar giant resonances in 12 C and 93 Nb through 6 Li scattering

Inelastic Li 6 scattering at 100 MeV/u on C 12 and Nb 93 has been measured with the high-resolution magnetic spectrometer Grand Raiden. The magnetic-rigidity settings of the spectrometer covered excitation energies from 10 to 40 MeV and scattering angles in the range 0 ° < θ lab. < 2 ° . The isoscalar giant monopole resonance was selectively excited in the present data. Measurements free of instrumental background and the very favorable resonance-to-continuum ratio of Li 6 scattering allowed for precise determination of the E 0 strengths in C 12 and Nb 93 . Additionally, it was found that the monopole strength in C 12 exhausts 52 ± 3 (stat.) ± 8 (sys.) % of the energy-weighted sum rule (EWSR), which is considerably higher than results from previous α -scattering experiments. The monopole strength in Nb 93 exhausts 92 ± 4 (stat.) ± 10 (sys.) % of the EWSR, and it is consistent with measurements of nuclei with mass number of A ≈ 90 . Such comparison indicates that the isoscalar giant monopole resonance distributions in these nuclei are very similar, and no influence due to nuclear structure was observed.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Properties of giant dipole resonances within an extended pairing model with a focus on spectral statistics

In this paper, we report on a study of the spectral features associated with dipole resonances in medium mass nuclei (E ≤ 12 MeV), as revealed in the framework of the spd-interacting boson model. The effect of pairing correlations on the theory follows from solutions obtained through an application of the Bethe Ansatz Equation. In general, calculated spectra around the critical point of the vibrational to γ-soft transitions appears to approach that of a Gaussian Orthogonal Ensemble, while near the rotational and vibrational limits of the theory the spectra show more regular behavior. Specifically, the results reveal that the statistical features of the spectra are sensitive to the vector boson pairing strength, c p , in the transition region; that is, when c p is zero, or when the system approaches one of its dynamical symmetries limits the spectrum display regular features, while for stronger c p values, or when near to the critical phase transition region, the spectral feature show more chaotic behavior. Overall, our results indicate that the statistical features are governed by the interplay between dipole resonant energies, pairing correlations, and interactions between and among the single and vector bosons modes of the theory. As part of this work we also found out that chaoticity occurs when results were fit to a Berry-Robnik distribution. Throughout our analyses, we used experimentally known information about both positive and negative parity states. Our findings suggest that dipole resonances appear to be best-described by Poisson statistics for A ≈ 32-138 nuclei.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Hadronic resonance production and interaction in p-Pb collisions at LHC energies in EPOS3

Using the EPOS3 model with the Ultrarelativistic Quantum Molecular Dynamics (UrQMD) model to describe the hadronic phase, we study the production of short-lived hadronic resonances and the modification of their yields and p T spectra in p-Pb collisions at √sNN= 5.02 TeV. High-multiplicity p-Pb collisions exhibit similar behavior to midperipheral Pb-Pb collisions at LHC energies, and we find indications of a short-lived hadronic phase in p-Pb collisions that can modify resonance yields and p T spectra through scattering processes. The evolution of resonance production is investigated as a function of the system size, which is related to the lifetime of the hadronic phase in order to study the onset and evolution of scattering effects in p-Pb collisions. We also study hadron production separately in the core and corona parts of these collisions and explore how this division affects the total particle yields as the system size increases.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Resonance-Enhanced Multiphoton Ionization in the X-Ray Regime

In this work, we report on the nonlinear ionization of argon atoms in the short wavelength regime using ultraintense x rays from the European XFEL. After sequential multiphoton ionization, high charge states are obtained. For photon energies that are insufficient to directly ionize a 1s electron, a different mechanism is required to obtain ionization to Ar 17+ . We propose this occurs through a two-color process where the second harmonic of the FEL pulse resonantly excites the system via a 1s→2p transition followed by ionization by the fundamental FEL pulse, which is a type of x-ray resonance-enhanced multiphoton ionization (REMPI). This resonant phenomenon occurs not only for Ar 16+ , but also through lower charge states, where multiple ionization competes with decay lifetimes, making x-ray REMPI distinctive from conventional REMPI. With the aid of state-of-the-art theoretical calculations, we explain the effects of x-ray REMPI on the relevant ion yields and spectral profile.

74 ATOMIC AND MOLECULAR PHYSICS↗

Search for a narrow resonance with a mass between 10 and 70 GeV decaying to a pair of photons in proton-proton collisions at $\sqrt{𝑠}$ = 13 TeV

The existence of a new spin-zero particle with a mass below the electroweak scale is predicted by several theoretical models. Searches for resonant production of photon pairs at the LHC are able to probe these models. We present a search for a narrow resonance produced through gluon fusion that decays into a pair of photons with an invariant mass between 10 and 70 GeV, using a proton-proton collision dataset from the CMS experiment. This dataset, corresponding to an integrated luminosity of 54.4 fb −1 , was recorded in 2018 at a center-of-mass energy of 13 TeV using a newly introduced diphoton trigger that enabled exploration of the low-mass diphoton spectrum. No significant excess above the expected background is observed. Upper limits are set on the product of the gluon fusion production cross section and the branching fraction of the diphoton decay of a narrow resonance. An interpretation of these limits within an effective field theory framework for axionlike particles is also provided.

axion-like particles↗

Strain-tunable microwave-resonance technique for quantum materials

By integrating a dielectric microwave resonator with a piezoelectric-based strain device, we develop an in situ strain-tunable microwave spectroscopy technique that enables contactless measurements of material properties under strain. To demonstrate the capability of this device, we measure the strain-dependent microwave surface impedance of the representative iron-based superconductor Ba⁢Fe 2 (As 1−𝑥 ⁢P 𝑥 ) 2 at the slightly overdoped composition. We successfully control and observe the suppression of superconductivity under both compressive and tensile anisotropic lattice distortions along the tetragonal [110] T direction, as manifested by changes in the quality factor and resonance frequency shifts of microwave resonance. Furthermore, strain-induced changes in microwave surface resistivity, an extension of conventional DC-limit transport elastoresistivity to the microwave regime, provide information on electronic anisotropy equivalent to that of DC elastoresistivity, while offering a contactless alternative. Furthermore, our strain-tunable cavity therefore serves as a powerful, contactless probe of fundamental material properties under strain and may also potentially facilitate the design of hybrid quantum systems with strain-engineered quantum degrees of freedom.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Tailoring ferromagnetic resonance in bicomponent artificial spin ices

Magnonic crystals are artificial media in which magnetic properties such as saturation magnetization or relative permeability are periodically modulated in space, allowing for effective control of the magnonic bandstructure by geometrical structuring. From this end, artificial spin ice - arrays of interacting nanomagnets - can be viewed as reprogrammable twodimensional magnonic crystal. Here, we introduce a new kind of bicomponent artificial spin ice that is made of two dissimilar ferromagnetic metals arranged on complementary lattice sites. It is shown that the resonant dynamics can effectively be controlled based on the distinct magnetic properties of the two materials. We use broadband ferromagnetic resonance to measure the spin-wave eigenmodes of the different sublattices. Here, we compare the ferromagnetic resonance spectra of the single component arrays with the spectrum of a bicomponent system that can be interpreted using a superposition principle. Furthermore, we show that the switching behavior of the sublattices affects one another.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Measurements of DC SQUID Damping Effects on Superconducting Resonant Circuits

Here, we present experimental measurements of SQUID-induced damping effects on strongly coupled, lumped-element resonators in the 500kHz–1 MHz frequency range. While dc SQUIDs are commonly used for sensitive readout of electromagnetic signals such as in lumped-element axion dark matter searches, coupling a dc SQUID to a resonant circuit modifies the circuit's resonance frequency, quality factor, noise, and impedance. These parameters have a direct impact on the science reach of axion dark matter detectors, making it important to understand SQUID damping contributions. We describe a helium dip probe and two-stage SQUID readout scheme used to probe SQUID damping effects. Measurements from this setup inform the design and operation of both future test platforms as well as next-generation dark-matter experiments.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

RUScal : Software for the analysis of resonant ultrasound spectroscopy measurements

Resonant ultrasound spectroscopy is used to nondestructively measure the elastic resonances of small solids to elucidate the material's elastic properties or other qualities like size, shape, or composition. In this work, we introduce the software RUScal for the purpose of determining elastic properties by analyzing the eigenfrequencies of solid specimens with common shapes, such as rectangular parallelepipeds, cylinders (solid and hollow tube), ellipsoids, and octahedrons, as well as irregularly shaped ellipsoids that can be described analytically. All symmetry classes are supported, from isotropic to triclinic, along with the option to add or remove up to three orthogonal mirror planes as well as the ability to reorient the crystal axes with respect the sample edges via Euler angles. Additional features include tools to help find initial sets of elastic constants, including grid exploration and Monte Carlo methods, a tool to analyze frequencies as a function of sample length or crystal orientation, an error analysis tool to assess fit quality, and formatting of the input and output files for batch fitting, e.g., as a function of temperature. This software was validated with published resonant ultrasound spectroscopy data for various materials, shapes, and symmetries with noted improvements in calculation time compared to finite element methods.

47 OTHER INSTRUMENTATION↗

Exploring baryon resonances with transition generalized parton distributions: status and perspectives

QCD gives rise to a rich spectrum of excited baryon states. Understanding their internal structure is important for many areas of nuclear physics, such as nuclear forces, dense matter, and neutrino-nucleus interactions. Generalized parton distributions (GPDs) are an established tool for characterizing the QCD structure of the ground-state nucleon. They are used to create 3D tomographic images of the quark/gluon structure and quantify the mechanical properties such as the distribution of mass, angular momentum, and forces in the system. Transition GPDs extend these concepts to N → N* transitions and can be used to characterize the 3D structure and mechanical properties of baryon resonances. They can be probed in high-momentum-transfer exclusive electroproduction processes with resonance transitions e + N → e' + M + N*, such as deeply-virtual Compton scattering (M = γ) or meson production (M = π, K, etc.), and in related photon/hadron-induced processes. This White Paper describes a research program aiming to explore baryon resonance structure with transition GPDs. This includes the properties and interpretation of the transition GPDs, theoretical methods for structures and processes, first experimental results from JLab 12 GeV, future measurements with existing and planned facilities (JLab detector and energy upgrades, COMPASS/AMBER, EIC, EicC, J-PARC, LHC ultraperipheral collisions), and the theoretical and experimental developments needed to realize this program.

Experimental Nuclear Physics↗

Plasmonic surface lattice resonances in nanoparticle arrays

This work reviews the literature and provides a detailed computational analysis of the optical properties of one- and two-dimensional arrays of silver and gold nanoparticles, with emphasis on surface lattice resonances (SLRs) that arise when localized plasmon resonances (LSPRs) in the nanoparticles couple to diffraction resonances that are determined by the interparticle spacing to give polariton modes in which the two types of excitations are coherently coupled. The computations are based on the coupled dipole approximation, which provides a nearly quantitative description of the extinction spectra for arrays of this type where the particles are well separated and not too large. The computations are used to determine many characteristics of SLRs associated with the lower polariton mode that is mostly photonic in nature, and we also study the upper polariton that is dominated by the LSPR response, as well as Rayleigh anomalies (RAs) that correspond to purely diffractive excitation. The calculations explore the sensitivity of these excitations to the directions of the incident wave and polarization vectors relative to the array axis, the effect of array spacing and number of particles in the array, and the effect of nanoparticle radius and background refractive indices. Details of the physical mechanisms involved in determining blue- and/or redshifts as structural parameters are varied is provided, with SLR’s being sensitive to far-field coupling, while LSPR’s can also be sensitive to near- and intermediatefield interactions that in some cases are similar to effects found in dye molecule aggregates.

77 NANOSCIENCE AND NANOTECHNOLOGY↗

Automating neutron resonances classification with Machine Learning [Slides]

Team reported the following accomplishments: the development of a Machine-Learning method to properly assign spins to neutron resonances (automated, general, reproducible); full integration with evaluated resonances in the Atlas (automation of new editions); training and optimization in synthetic data; validation and deployment to real experimental resonances. Future perspectives include exploration of other classifiers and hyper-parameter combinations, further validation with well-known nucleus (e.g. 235 U), and publication pipeline.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Lumbar spine disc height and curvature responses to an axial load generated by a compression device compatible with magnetic resonance imaging

STUDY DESIGN: Axial load-dependent changes in the lumbar spine of supine healthy volunteers were examined using a compression device compatible with magnetic resonance imaging. OBJECTIVE: To test two hypotheses: Axial loading of 50% body weight from shoulder to feet in supine posture 1) simulates the upright lumbar spine alignment and 2) decreases disc height significantly. SUMMARY OF BACKGROUND DATA: Axial compression on the lumbar spine has significantly narrowed the lumbar dural sac in patients with sciatica, neurogenic claudication or both. METHODS: Using a device compatible with magnetic resonance imaging, the lumbar spine of eight young volunteers, ages 22 to 36 years, was axially compressed with a force equivalent to 50% of body weight, approximating the normal load on the lumbar spine in upright posture. Sagittal lumbar magnetic resonance imaging was performed to measure intervertebral angle and disc height before and during compression. RESULTS: Each intervertebral angle before and during compression was as follows: T12-L1 (-0.8 degrees +/- 2.5 degrees and -1.5 degrees +/- 2.6 degrees ), L1-L2 (0.7 degrees +/- 1.4 degrees and 3.3 degrees +/- 2.9 degrees ), L2-L3 (4.7 degrees +/- 3.5 degrees and 7.3 degrees +/- 6 degrees ), L3-L4 (7.9 degrees +/- 2.4 degrees and 11.1 degrees +/- 4.6 degrees ), L4-L5 (14.3 degrees +/- 3.3 degrees and 14.9 degrees +/- 1.7 degrees ), L5-S1 (25.8 degrees +/- 5.2 degrees and 20.8 degrees +/- 6 degrees ), and L1-S1 (53.4 degrees +/- 11.9 degrees and 57.3 degrees +/- 16.7 degrees ). Negative values reflect kyphosis, and positive values reflect lordosis. A significant difference between values before and during compression was obtained at L3-L4 and L5-S1. There was a significant decrease in disc height only at L4-L5 during compression. CONCLUSIONS: The axial force of 50% body weight in supine posture simulates the upright lumbar spine morphologically. No change in intervertebral angle occurred at L4-L5. However, disc height at L4-L5 decreased significantly during compression.

Non-NASA Center↗

Optimization of Coherent Lidar Performance Using Graded- Reflectance Transmitter Resonator Optics in the Low Equivalent Fresnel Number Region

Using a diffractive eigenmode treatment to model the laser output, we show that graded-reflectance resonator optics offer significant efficiency benefits over conventional hard-edge coupled unstable resonators in the context of coherent detection lidar applications. Extending previous work pertinent to the high equivalent Fresnel number regime, we have modelled the optimum performance of a notional super-Gaussian coupled cavity as a function of the key resonator parameters in the low equivalent Fresnel number regime.

lidar graded-reflectance transmitter resonator↗