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DOE OSTI2021

Unitarity violation and the geometry of Higgs EFTs

We derive the scale of unitarity violation from the geometry of Effective Field Theory (EFT) extensions of the Standard Model Higgs sector. The high-energy behavior of amplitudes with more than four scalar legs depends on derivatives of geometric invariants with respect to the physical Higgs field h, such that higher-point amplitudes begin to reconstruct the scalar manifold away from our vacuum. In theories whose low-energy limit can be described by the Higgs EFT (HEFT) but not the Standard Model EFT (SMEFT), non-analyticities in the vicinity of our vacuum limit the radius of convergence of geometric invariants, leading to unitarity violation at energies below 4πv. Our results unify approaches to the HEFT/SMEFT dichotomy based on unitarity, analyticity, and geometry, and more broadly illustrate the sense in which observables probe the geometry of an EFT. Along the way, we provide novel basis-independent results for Goldstone/Higgs boson scattering amplitudes expressed in terms of geometric covariant quantities.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2018

Multipath Curved Planar Reformations of Peripheral CT Angiography: Diagnostic Accuracy and Time Efficiency

ObjectivesTo compare diagnostic performance and time efficiency between 3D multipath curved planar reformations (mpCPRs) and axial images of CT angiography for the pre-interventional assessment of peripheral arterial disease (PAD), with digital subtraction angiography as the standard of reference.MethodsForty patients (10 females, mean age 72 years), referred to CTA prior to endovascular treatment of PAD, were prospectively included and underwent peripheral CT angiography. A semiautomated toolbox was used to render mpCPRs. Twenty-one arterial segments were defined in each leg; for each segment, the presence of stenosis > 70% was assessed on mpCPRs and axial images by two readers, independently, with digital subtraction angiography as gold standard.ResultsBoth readers reached lower sensitivity (Reader 1: 91 vs. 94%, p = 0.08; Reader 2: 89 vs. 93%, p = 0.03) but significantly higher specificity (Reader 1: 94 vs. 89%, p < 0.01; Reader 2: 96 vs. 95%, p = 0.01) with mpCPRs than with axial images. Reader 1 achieved significantly higher accuracy with mpCPRs (93 vs. 91%, p = 0.02), and Reader 2 had similar overall accuracy in both evaluations (94 vs. 94%, p = 0.96). Both readers read mpCPRs significantly faster than axial images (Reader 1: 5′45″ based on mpCPRs vs. 7′40″ based on axial images; Reader 2: 4′41″ based on mpCPRs vs. 6′57″ based on axial images; p < 0.01).ConclusionsmpCPRs are a promising 3D reformation technique that facilitates a fast assessment of PAD with high diagnostic accuracy.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2019

Focal Stenting of Complex Femoropopliteal Lesions with the Multi-LOC Multiple Stent Delivery System: 12-Month Results of the Multicenter LOCOMOTIVE Study

Introduction: The purpose of this observational study is to report the 12-month clinical outcomes with the novel Multiple Stent Delivery System (MSDS) to treat complex femoropopliteal lesions. Previously, we reported the 6-month clinical outcomes of the all-comers LOCOMOTIVE study, which demonstrated the safety and efficacy of the MSDS with a favorable target lesion revascularization (TLR) rate of 5.3% and a 90.7% patency rate at 6 months in claudicants and critical limb ischemia patients. The 12-month outcomes of LOCOMOTIVE registry are presented in this report. ClinicalTrials.gov Identifier: NCT02531230. Methods: The LOCOMOTIVE study (Multi-LOC for flOw liMiting Outcomes after POBA and/or DCB Treatment in the infrainguinal position with the objecIVE to implant multiple stent segments) investigates the efficacy and safety of the MSDS approach in an all-comers population. Clinical follow-ups at 6 and 12 months are scheduled to assess TLR, ABI, and vessel patency based on sonographic imaging. Results: At 12 months, the primary unassisted patency was 85.7% and all-cause TLR rate was 9.3% in the overall cohort. Between baseline and 12 months, the target leg ABI increased from 0.62 ± 0.24 to 0.91 ± 0.38 (p < 0.001) and the mean Rutherford class improved from 3.5 to 1.9 (p < 0.001). Conclusions: Over a 12-month post-procedural period, MSDS for focal provisional stenting of complex femoropopliteal lesions demonstrated a promising primary patency and freedom from TLR after 12 months. In addition, significant improvements were observed in symptom classification and hemodynamics.

62 RADIOLOGY AND NUCLEAR MEDICINE↗

DOE OSTI2018

Comparison of neutron organ and effective dose coefficients for PIMAL stylized phantom in bent postures in standard irradiation geometries

Neutron dose coefficients for standard irradiation geometries have been reported in International Commission on Radiological Protection (ICRP) Publication 116 for the ICRP Publication 110 adult reference phantoms. In the present paper, organ and effective dose coefficients have been calculated for a receptor in both upright and articulated (bent) postures representing more realistic working postures exposed to a mono-energetic neutron radiation field. This work builds upon prior work by Dewji and co-workers comparing upright and bent postures for exposure to mono-energetic photon fields. Simulations were conducted using the Oak Ridge National Laboratory’s articulated stylized adult phantom, “Phantom wIth Moving Arms and Legs” (PIMAL) software package, and the Monte Carlo N-Particle (MCNP) version 6.1.1 radiation transport code. Organ doses were compared for the upright and bent (45° and 90°) phantom postures for neutron energies ranging from 1 × 10 -9 to 20 MeV for the ICRP Publication 116 external exposure geometries—antero-posterior (AP), postero-anterior (PA), and left and right lateral (LLAT, RLAT). Using both male and female phantoms, effective dose coefficients were computed using ICRP Publication 103 methodology. The resulting coefficients for articulated phantoms were compared to those of the upright phantom. Computed organ and effective dose coefficients are discussed as a function of neutron energy, phantom posture, and source irradiation geometry. For example, it is shown here that for the AP and PA irradiation geometries, the differences in the organ coefficients between the upright and bent posture become more pronounced with increasing bending angle. In the AP geometry, the brain dose coefficients are expectedly higher in the bent postures than in the upright posture, while all other organs have lower dose coefficients, with the thyroid showing the greatest difference. Finally and overall, the effective dose estimated for the upright phantom is more conservative than that for the articulated phantom, which may have ramifications in the estimation or reconstruction of radiation doses.

61 RADIATION PROTECTION AND DOSIMETRY↗

DOE OSTI2017

A Method to Alleviate the Long History Problem Encountered in Monte Carlo Simulations via Weight Window Variance Reduction

When the weight window is implemented in large and complex models, streaming path and deep penetration could lead to a long history problem that takes a disproportionate amount of time for the accomplishment of Monte Carlo simulations and exerts a detrimental effect on the efficiency of parallel computing. An approach set the limitation of weight window splitting was proposed for the alleviation of long history problem. Tests were conducted on a streaming dog-leg geometry model and a 3D model of the Chinese Fusion Engineering Testing Reactor. The results show that a suitable parameter in the alleviation method could optimize both the performance of variance reduction and the efficiency of parallel calculation, which makes long history problem tractable.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗

DOE OSTI2018

Developments of Highly Multiplexed, Multi-chroic Pixels for Balloon-Borne Platforms

We present our work to develop and characterize low thermal conductance bolometers that are part of sinuous antenna multi-chroic pixels (SAMP). We use longer, thinner and meandered bolometer legs to achieve 9 pW/K thermal conductance bolometers. We also discuss the development of inductor–capacitor chips operated at 4 K to extend the multiplexing factor of the frequency domain multiplexing to 105, an increase of 60% compared to the factor currently demonstrated for this readout system. This technology development is motivated by EBEX-IDS, a balloon-borne polarimeter designed to characterize the polarization of foregrounds and to detect the primordial gravity waves through their B-mode signature on the polarization of the cosmic microwave background. EBEX-IDS will operate 20,562 transition edge sensor bolometers spread over 7 frequency bands between 150 and 360 GHz. Balloon and satellite platforms enable observations at frequencies inaccessible from the ground and with higher instantaneous sensitivity. This development improves the readiness of the SAMP and frequency domain readout technologies for future satellite applications.

42 ENGINEERING↗

DOE OSTI2018

Magnetic Sensitivity of AlMn TESes and Shielding Considerations for Next-Generation CMB Surveys

In the next decade, new ground-based cosmic microwave background (CMB) experiments such as Simons Observatory, CCAT-prime, and CMB-S4 will increase the number of detectors observing the CMB by an order of magnitude or more, dramatically improving our understanding of cosmology and astrophysics. These projects will deploy receivers with as many as hundreds of thousands of transition edge sensor (TES) bolometers coupled to superconducting quantum interference device (SQUID)-based readout systems. It is well known that superconducting devices such as TESes and SQUIDs are sensitive to magnetic fields. However, the effects of magnetic fields on TESes are not easily predicted due to the complex behavior of the superconducting transition, which motivates direct measurements of the magnetic sensitivity of these devices. We present comparative four-lead measurements of the critical temperature versus applied magnetic field of AlMn TESes varying in geometry, doping, and leg length, including Advanced ACT and POLARBEAR-2/Simons Array bolometers. MoCu ACTPol TESes are also tested and are found to be more sensitive to magnetic fields than the AlMn devices. We present an observation of weak-link-like behavior in AlMn TESes at low critical currents. We also compare measurements of magnetic sensitivity for time division multiplexing SQUIDs and frequency division multiplexing microwave (mMUX) rf-SQUIDs. We discuss the implications of our measurements on the magnetic shielding required for future experiments that aim to map the CMB to near-fundamental limits.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2018

Twin-Slot Antenna-Coupled Superconducting Ti Transition-Edge Sensor at 350 GHz

We have developed four-leg-supported superconducting Ti transition-edge sensors (TES) formed by KOH wet etching. Energy relaxation mechanism is changed from electron–phonon coupling to diffusive phonon after wet etching. The current–voltage curves of the same TES device were measured before and after wet etching. After wet etching, its thermal conductance (G) is reduced to 500 pW/K from 8950 pW/K. The measured effective response time (τ{sub eff}) is 143 μs, about 30 times larger. In addition, we have studied the optical noise equivalent power (NEP) with a cryogenic blackbody in combination with metal-mesh filters to define the radiation bandwidth. The obtained optical NEP is 5 × 10{sup −16} W/√Hz, which is suitable for ground-based astronomical applications.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2019

Developing AlMn Films for Argonne TES Fabrication

The reference design for the next-generation cosmic microwave background (CMB) experiment, CMB-S4, relies on large arrays of transition-edge sensor (TES) bolometers coupled to Superconducting Quantum Interference Device (SQUID)-based readout systems. Mapping the CMB to near cosmic variance limits will enable the search for signatures of inflation and constrain dark energy and neutrino physics. AlMn TESes provide simple film manufacturing and highly uniform arrays over large areas to meet the requirements of the CMB-S 4 experiment. TES parameters such as critical temperature and normal resistance must be tuned to experiment specifications and can be varied based on geometry and steps in the fabrication process such as deposition layering, geometry, and baking time and temperature. Using four-terminal sensing, we measured T C and R N of AlMn 2000 ppm films and devices of varying thicknesses fabricated at Argonne National Laboratory to motivate device geometries and fabrication processes to tune T C to 150–200 mK and R N to ~10 mΩ. Furthermore, measurements of IV curves and time constants for the resulting devices of varying leg length were made using time-division SQUID multiplexing and determined TC, G, k, f 3db , and RN. We present the results of these tests along with the geometries and fabrication steps used to tune the device parameters to the desired limits.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

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 OSTI2018

Finite Size Effects in Anisotropic u = ∞ Hubbard Ladder Rings

We apply perturbation theory and cyclic spin permutation formalism to study the lowest energy states of the infinite-repulsion Hubbard model on finite fragments of n-leg ladder rings and show jump-wise behavior of the ground state spin S{sub 0} as a function of fragment parameters.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2020

Iron-Based Chalcogenide Spin Ladder BaFe2 X 3 (X = Se,S)

The relevance of magnetic, structural, orbital, and charge degrees of freedom in the iron-based superconductors (FeSCs) and related materials occupies a central focus in condensed matter physics. While the majority of iron-based materials exhibit the same two-dimensional iron square lattice structural motif, a family of AFe2X3 (X = Se,S) compounds introduces a quasi-one-dimensional (1D) ladder motif, which resembles the two-legged spin ladder copper oxide materials. Furthermore, unlike most parent compounds of FeSCs, the members of this spin ladder family are insulators. Recently, a superconducting transition has been observed under pressure with Tc up to 24 K, similar to the pressure-induced superconductivity in the copper oxide ladder Sr14-xCaxCu24O41 material, stimulating much interest. Here, we review the magnetic, structural, and electronic properties in this family, particularly in the BaFe2X3 series tuned by pressure and by chemical substitution. The established pressure-temperature (P-T) and carrier concentration-temperature (x-T) phase diagrams in related materials provide useful information to extend the variety of high-temperature superconductors and compare with other FeSCs. We also review some essential information about analogous square lattice FeSCs.

Wu, S↗

DOE OSTI2019

Influence of Obstruction at Gas-Injection Nozzles (Number and Position) in RH Degasser Process

One of the main problems that affects Ruhrstahl-Heraeus (RH) degasser circulation rate is the obstruction of the gas-injection nozzles. This study aims to elucidate the effects of obstructions in quantity and location using a physical model that depicts 16 injection nozzles on the up-leg distributed symmetrically in 2 rings (8 nozzles/ring). We simulated six, symmetric and nonsymmetric, obstruction conditions to gas flow. The gas-flow rate was varied from 30 to 130 NL/min. The results for symmetric obstructions when the gas-flow rate is kept constant, indicates that the circulation rate in the equipment does not significantly change. However, when these obstructions are non-symmetric, the circulation rate varies drastically, even when the gas-flow rate is kept constant. The analysis of the experimental data generated from this study allowed to determine an equation for the circulation rate that takes into consideration the number and distribution of blocked nozzles.

42 ENGINEERING↗

DOE OSTI2019

Numerical Simulation of Gas and Liquid Two-Phase Flow in the RH Process

A mathematical model has been established to simulate the gas–liquid two-phase flow in the RH process. The effects of interphase forces and the bubble-induced turbulence on the fluid flow and motion of gas bubbles were investigated. The interphase forces include the drag force, the virtual mass force, the lift force, and the pressure gradient force, respectively. The prediction results of the liquid velocity and the recirculation rate were compared with the experimental data measured with a Particle Image Velocimetry technique. The results indicated that the drag force and the virtual mass force dominated the gas plume shape in the up-leg snorkel, and significantly influenced the liquid velocity and the distribution of the gas phase. The lift force mainly affected the spreading of gas bubbles in the radial direction of the snorkel. However, the pressure gradient force could be neglected because it had no effect on the liquid velocity and the gas volume fraction. The increase of the bubble-induced turbulence decreased the liquid velocity, and by adjusting the lift force, it widened the shape of the individual gas plumes. To accurately simulate the gas–liquid flow behavior in the RH degasser, these appropriate parameters, such as the drag coefficient, the virtual mass coefficient, the lift coefficient, and the bubble-induced turbulence coefficient, were determined by comparing the predicted results and the measured data.

42 ENGINEERING↗

DOE OSTI2024

Single-atom materials boosting wearable orthogonal uric acid detection

Abstract Uric acid (UA) is a vital biomarker for the diagnosis and management of various health conditions, including cardiovascular diseases, gout, kidney disorders, metabolic syndrome, and wound healing. Despite significant advances in wearable sensor technology, challenges persist in developing wearable sensors that are capable of maintaining high sensitivity, selectivity, and stability. In this study, we present an epidermal sensing platform enhanced with single-atom materials (SAMs) designed for flexible and orthogonal electrochemical detection of UA. We designed and synthesized an SAM with Fe-N 5 active sites to boost the electrochemical sensing signals, integrating it with laser-engraved graphene (LEG) to fabricate a wearable SAM-based UA patch sensor. This design provides superior UA detection performance compared to sensors based on conventional nanomaterials. In addition, we enhanced the detection accuracy and range by using an orthogonal approach that combines direct oxidation through differential pulse voltammetry (DPV) along with parallel biocatalytic amperometric detection. The resulting SAM-based UA orthogonal sensor patch demonstrated exceptional performance in wearable applications through tests measuring sweat UA levels in subjects before and after consuming a purine-rich diet. Graphical Abstract

Ding, Shichao↗

DOE OSTI2017

A simulation of I 2 S-LWR selected transients

The Integral Inherently Safe (I 2 S-LWR) reactor was designed to improve the safety performance of PWR types reactors, and several design basis accidents were eliminated using innovative approaches to the I 2 S-LWR plant layout. However, some accidents such as station blackout (SBO), main steam line break (MSLB) type accident – the secondary hot leg break (SHLB) – were deemed statistically relevant, and the work performed here was to simulate these events using the system thermal–hydraulics code RELAP5 coupled to the 3D spatial kinetics code PARCS. The safety response of the reactor to a station blackout is predicted to be acceptable at both beginning of cycle (BOC) and end of cycle EOC core conditions with either the UO 2 or U 3 Si 2 fuel options considered here. In the analysis of the SHLB performed here, an unprotected (no SCRAM) condition was assumed to highlight the I 2 S-LWR capabilities. Results indicate that with the UO 2 core, the fuel temperatures rise notably, but no fuel melting was predicted and departure from nucleate boiling ratio (DNBR) limits were not exceeded. Similarly, the U 3 Si 2 fuel performed well, but with lower fuel temperatures and decreased DNBR. Following the break of the steam line in the I 2 S-LWR, shutdown is achieved after about two minutes via negative reactivity from loss of primary flow. In all cases considered, the I 2 S-LWR appears to accomplish the goals of increased safety performance. Further design improvements and other fuel options may marginally improve on the observed safety performance. Additionally, higher fidelity analysis with the next generation subchannel, Computational Fluid Dynamics (CFD), or full core transport may be useful in refining the prediction of the peak fuel and cladding temperatures, as well limiting DNBR during the accidents.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2018

Band-gap structure and chiral discrete solitons in optical lattices with artificial gauge fields

We study three-leg-ladder optical lattices loaded with repulsive atomic Bose–Einstein condensates and subjected to artificial gauge fields. By employing the plane-wave analysis and variational approach, we analyze the band-gap structure of the energy spectrum and reveal the exotic swallow-tail loop structures in the energy-level anti-crossing regions due to an interplay between the atom–atom interaction and artificial gauge field. In further, we discover stable discrete solitons residing in the forbidden zone above the maxima of the highest band, and we find that these discrete solitons are associated with chiral edge currents.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

DOE OSTI2018

Micro-environmental control for efficient local heating: CFD simulation and manikin test verification

Micro-environment control system has been proved to be able to provide local thermal comfort control. It also has the potential to save building energy by relaxing the control on the unoccupied space. This work aims at designing an efficient heating delivering device (HDD) to locally warm the person to restore thermal comfort when the unoccupied space temperature is reduced from 70.0 °F to 66.0 °F to save the energy. A three-stage approach was developed for designing the HDD including the initial stage of developing by CFD simulation, the second stage of manikin test verification and final stage of human subject test confirmation. The results of the first two stages were presented and discussed in this work. It was shown that convective heating was not efficient enough unless a confinement box was used to hold the hot air around the legs and feet. A more ergonomically friendly design of using a foot warmer was finally proved to be a better solution for individually heating by both simulation and experiments since it can heat the occupant sufficiently. The ability of using CFD to predict heat loss from the clothed human body and its limitation was also investigated. It was found that with proper clothing insulation, the CFD can give a reasonable prediction, although simulating the clothing as a layer of certain thermal resistance might be problematic regarding the structure and permeability of the clothing material. In conclusion, a more appropriate method for simulating the clothing was needed for better prediction in the future.

42 ENGINEERING↗