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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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Coupling of electroelastic dynamics and direct contact ultrasonic drying formulation for annular piezoelectric bimorph transducers

A newly developed technique for drying clothes without thermal energy has been developed through the utilization of ultrasonic vibrations from piezoelectric transducers. The novel technique incorporates the actuation of a thin stainless steel disk in contact with wet fabric via annular piezoelectric rings, where water in the liquid form is atomized, transported through microchannels in the disk, and ejected as a mist. In such a system, resonance matching between the actuation portion of the transducer and the portion contacting fabric must be realized, with theoretical results from the developed electromechanical model showing a reduction in energy consumption by 50% when resonance matching is achieved. The electrically coupled distributed parameter model for an annular bimorph piezoelectric transducer is developed for optimization of ultrasonic drying technology. The thickness mode vibrations are shown to dominate the behavior of the system, where the analytically developed model can be optimized to increase the output acceleration of the transducer, thus increasing drying performance. Here, the electromechanical equation developed will be connected to the drying rates of fabrics in contact with said vibrations, where the novelty of the coupled equations and its description of the physics of ultrasonic drying will be discussed.

36 MATERIALS SCIENCE↗
DOE OSTI2022

Spin resonance canceling lattice cell design principles

We show how to construct an accelerator lattice cell which minimizes all intrinsic spin resonance. We then apply this approach to various toy electron and proton accelerators, considering, AGS-like and CEPC/FCC-ee and FCC-hh like rings.

43 PARTICLE ACCELERATORS↗
DOE OSTI2020

Flowthrough Pretreatment of Softwood under Water-only and Alkali Conditions

Flowthrough pretreatment provides valuable insight in the fundamentals of deconstruction of plant biomass. In this study, the potential softwood degradation pathways under water-only and alkali conditions were determined by elucidating the deconstructed biomass-derived products at 0-270 °C for 2-10 min at a flow rate of 25 mL/min with water-only or alkaline at initial pH of 8, 9, 11, and 12, respectively. Results indicated that the initial pH value was a convenient indicator along with the severity parameter to control biomass degradation through the non-oxidative (pH<9) and oxidative (pH=9) pathways. Up to 100 % of hemi-sugars, 90 % of cellulose, and 70 % of lignin were derived from softwood under non-oxidative conditions at severity parameter LogR0 around 5.5, respectively. On the contrary, at pH 12, the oxidative degradation resulted in pretreated hydrolysate rich in monomeric and oligomeric phenolic products as well as glycolic acid, acetic acid, and formic acid from carbohydrates. The two dimensional 1H-13C heteronuclear single quantum coherence (HSQC) nuclear magnetic resonance (NMR) analysis revealed that non-oxidative degradation at initial pH values lower than 9 mainly cleaved ß-O-4, all of the ß-ß, and ß-5/a-O-4 linkages, whereas substantial aromatic ring structures with limited ß-O-4 structures remaining at pH 12 through oxidative degradation.

Zhang, Libing↗
DOE OSTI2024

Flattening the field during injection in the Fermilab booster using dipole corrector magnets

The FNAL Booster is a fast cycling 15 Hz resonant circuit synchrotron accelerating proton beam from 400 MeV to 8 GeV. The linac pulse injected into the Booster is ~32 μsec long and fills the ring by multi-turn charge-exchange injection. As part of the PIP-II project, the Booster injection energy and repetition rate will be increased to 800 MeV and 20 Hz respectively. Due to much reduced average current in the new superconducting PIP-II linac, the injection time will increase to 550 μs. A shorter machine cycle coupled to a longer injection time make flattening the injection porch B-field during injection important requirement for successful PIP-II operation. We aim to achieve: (1) flattening of the net bending during injection using dipole correctors, and (2) using a new system based on an Altera FPGA board, reduction of the cycle-to-cycle bending field variation caused by current jitter in the Gradient Magnet Power Supply (GMPS). While the flat injection scheme is essential to future PIP-II operations, it should also noticeably improve efficiency for present HEP operations.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

Harmonic Slip-Stacking

Particle accelerators employ slip-stacking configurations to store two particle beams with disparate momenta within a single ring. Additionally, A novel slip-stacking configuration employing a harmonic RF cavity was proposed and studied. Anticipated benefits of the harmonic cavity include mitigating parametric resonances, minimizing emittance growth, and significantly expanding the stable longitudinal phase-space area. By surpassing the requirements of PIP-II operation, the harmonic RF cavity will support extending slip-stacking operation for subsequent beam power upgrades of Main Injector, including a proposed cycle rate improvement. Our ongoing research will verify the simulation of harmonic slip-stacking (HSS) operation under RF phase-errors, such as those causes by beam-loading effects.

Habibeh, Mohammad↗
DOE OSTI2024

Flattening the Field during Injection in the Fermilab Booster using Dipole Corrector Magnets

The FNAL Booster is a fast cycling 15 Hz resonant circuit synchrotron accelerating proton beam from 400 MeV to 8 GeV. The linac pulse injected into the Booster is ˜32 usec long and fills the ring by multi-turn charge-exchange injection. As part of the PIP-II project, the Booster injection energy and repetition rate will be increased to 800 MeV and 20 Hz respectively. Due to much reduced average current in the new superconducting PIP-II linac, the injection time will increase to 550us. A shorter machine cycle coupled to a longer injection time make flattening the injection porch B-field during injection important requirement for successful PIP-II operation. We aim to achieve: (1) flattening of the net bending during injection using dipole correctors, and (2) using a new system based on an Altera FPGA board, reduction of the cycle-to-cycle bending field variation caused by current jitter in the Gradient Magnet Power Supply (GMPS). While the flat injection scheme is essential to future PIP-II operations, it should also noticeably improve efficiency for present HEP operations.

43 PARTICLE ACCELERATORS↗
DOE OSTI2023

High efficiency radio frequency antennas for amplifier free quantum sensing applications

Radio frequency (RF) signals are frequently used in emerging quantum applications due to their spin state manipulation capability. Efficient coupling of RF signals into a particular quantum system requires the utilization of carefully designed and fabricated antennas. Nitrogen vacancy (NV) defects in diamond are commonly utilized platforms in quantum sensing experiments with the optically detected magnetic resonance (ODMR) method, where an RF antenna is an essential element. We report on the design and fabrication of high efficiency coplanar RF antennas for quantum sensing applications. Single and double ring coplanar RF antennas were designed with -37 dB experimental return loss at 2.87 GHz, the zero-field splitting frequency of the negatively charged NV defect in diamond. The efficiency of both antennas was demonstrated in magnetic field sensing experiments with NV color centers in diamond. In conclusion, an RF amplifier was not needed, and the 0 dB output of a standard RF signal generator was adequate to run the ODMR experiments due to the high efficiency of the RF antennas.

47 OTHER INSTRUMENTATION↗
DOE OSTI2022

Molecular weight growth by the phenyl + cyclopentadienyl reaction: Well-skipping, ring-opening, and dissociation

Radical-radical reactions contribute to molecular weight growth of polycyclic aromatic hydrocarbons (PAHs), but their role is not well understood. The phenyl (Ph, C 6 H 5 ) + cyclopentadienyl (C 5 H 5 ) reaction has not been studied but can serve as a surrogate reaction for many reactions of larger aryl-σ radicals with resonance-stabilized π-radicals. The adducts of these reactions easily lose an H atom to produce a new π-radical. Here, through a combination of dilute flash pyrolysis experiments, theory, and simulation, we find that for the title reaction, substantial Ph—C 5 H 4 + H is formed, dominantly by a well-skipping pathway, at conditions around 30 Torr and 1400 K. This radical is thermally stable at moderate temperatures but decomposes at higher temperatures following ring opening of the 5-member ring. Products corresponding to the loss of H, C 2 H 2 , and C 3 H 3 are observed experimentally. Calculation of the C 11 H 9 potential energy surface affirms that these are expected decomposition products and reveals multiple possible pathways.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Tuning the reactivity of carbon surfaces with oxygen-containing functional groups

Oxygen-containing carbons are promising supports and metal-free catalysts for many reactions. However, distinguishing the role of various oxygen functional groups and quantifying and tuning each functionality is still difficult. Here we investigate the role of Brønsted acidic oxygen-containing functional groups by synthesizing a diverse library of materials. By combining acid-catalyzed elimination probe chemistry, comprehensive surface characterizations, 15N isotopically labeled acetonitrile adsorption coupled with magic-angle spinning nuclear magnetic resonance, machine learning, and density-functional theory calculations, we demonstrate that phenolic is the main acid site in gas-phase chemistries and unexpectedly carboxylic groups are much less acidic than phenolic groups in the graphitized mesoporous carbon due to electron density delocalization induced by the aromatic rings of graphitic carbon. The methodology can identify acidic sites in oxygenated carbon materials in solid acid catalyst-driven chemistry.

Zhou, Jiahua↗
DOE OSTI2023

Nuclear quadrupole resonance spectroscopy with a femtotesla diamond magnetometer

Radio frequency (RF) magnetometers based on nitrogen vacancy centers in diamond are predicted to offer femtotesla sensitivity, but previous experiments were limited to the picotesla level. We demonstrate a femtotesla RF magnetometer using a diamond membrane inserted between ferrite flux concentrators. The device provides ~300-fold amplitude enhancement for RF magnetic fields from 70 kHz to 3.6 MHz, and the sensitivity reaches ~70 fT√s at 0.35 MHz. The sensor detected the 3.6-MHz nuclear quadrupole resonance (NQR) of room-temperature sodium nitrite powder. The sensor’s recovery time after an RF pulse is ~35 μs, limited by the excitation coil’s ring-down time. The sodium-nitrite NQR frequency shifts with temperature as -1.00±0.02 kHz/K, the magnetization dephasing time is T 2 *=887±51 μs, and multipulse sequences extend the signal lifetime to 332±23 ms, all consistent with coil-based studies. Our results expand the sensitivity frontier of diamond magnetometers to the femtotesla range, with potential applications in security, medical imaging, and materials science.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2022

Manufacturing the Harmonic Kicker Cavity Prototype for the Electron-Ion Collider

High-bunch-frequency beam-separation schemes, such as the injection scheme proposed for the Rapid Cycling Synchrotron at the Electron-Ion Collider, demand rise and fall times an order of magnitude below what can realistically be accomplished with a stripline kicker. Nanosecond-time-scale kick waveforms can instead be obtained by Fourier synthesis in a harmonically resonant quarter-wave radio-frequency cavity which is optimized for high shunt impedance. Originally developed for the Jefferson Lab Electron-Ion Collider (JLEIC) Circulator Cooler Ring, a hypothetical 11-pass ring driven by an energy-recovery linac at Jefferson Lab, our high-power prototype of such a harmonic kicker cavity, which operates at five modes at the same time, will demonstrate the viability of this concept with a beam test at Jefferson Lab. As the geometry of the cavity, tight mechanical tolerances, and number of ports complicate the design and manufacturing process, special care must be given to the order of the manufacturing steps. We present our experiences with the manufacturability of the present design, lessons learned, and first RF test results from the prototype.

Overstreet, S. A.↗
DOE OSTI2022

Manufacturing the Harmonic Kicker Cavity Prototype for the Electron-Ion Collider

High-bunch-frequency beam-separation schemes, such as the injection scheme proposed for the Rapid Cycling Synchrotron at the Electron-Ion Collider, demand rise and fall times an order of magnitude below what can realistically be accomplished with a stripline kicker. Nanosecond-time-scale kick waveforms can instead be obtained by Fourier synthesis in a harmonically resonant quarter-wave radio-frequency cavity which is optimized for high shunt impedance. Originally developed for the Jefferson Lab Electron-Ion Collider (JLEIC) Circulator Cooler Ring, a hypothetical 11-pass ring driven by an energy-recovery linac at Jefferson Lab, our high-power prototype of such a harmonic kicker cavity, which operates at five modes at the same time, will demonstrate the viability of this concept with a beam test at Jefferson Lab. As the geometry of the cavity, tight mechanical tolerances, and number of ports complicate the design and manufacturing process, special care must be given to the order of the manufacturing steps. We present our experiences with the manufacturability of the present design, lessons learned, and first RF test results from the prototype.

Overstreet, S. A.↗
DOE OSTI2024

Capturing the generation and structural transformations of molecular ions

Molecular ions are ubiquitous and play pivotal roles in many reactions, particularly in the context of atmospheric and interstellar chemistry. However, their structures and conformational transitions, particularly in the gas phase, are less explored than those of neutral molecules owing to experimental difficulties. A case in point is the halonium ions, whose highly reactive nature and ring strain make them short-lived intermediates that are readily attacked even by weak nucleophiles and thus challenging to isolate or capture before they undergo further reaction. Here we show that mega-electronvolt ultrafast electron diffraction (MeV-UED), used in conjunction with resonance-enhanced multiphoton ionization, can monitor the formation of 1,3-dibromopropane (DBP) cations and their subsequent structural dynamics forming a halonium ion. We find that the DBP + cation remains for a substantial duration of 3.6 ps in aptly named ‘dark states’ that are structurally indistinguishable from the DBP electronic ground state. The structural data, supported by surface-hopping simulations and ab initio calculations, reveal that the cation subsequently decays to iso-DBP + , an unusual intermediate with a four-membered ring containing a loosely bound bromine atom, and eventually loses the bromine atom and forms a bromonium ion with a three-membered-ring structure. We anticipate that the approach used here can also be applied to examine the structural dynamics of other molecular ions and thereby deepen our understanding of ion chemistry.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

High-precision mass measurement of 103 Sn restores smoothness of the mass surface

As a step towards the ultimate goal of a high-precision mass measurement of doubly magic 100 Sn, the mass of 103 Sn was measured at the Low Energy Beam and Ion Trap (LEBIT) located at the Facility for Rare Isotope Beams (FRIB). Utilizing the time-of-flight ion cyclotron resonance technique, a mass uncertainty of 3.7 keV was achieved, an improvement by more than an order of magnitude compared to a recent measurement performed in 2023 at the Cooler Storage Ring (CSRe) in Lanzhou. Although the LEBIT and CSRe mass measurements of 103 Sn are in agreement, they diverge from the experimental mass value reported in the 2016 version of the Atomic Mass Evaluation (AME2016), which was derived from the measured 𝑄 𝛽 + value and the mass of 103 In. In AME2020, this indirectly measured 103 Sn mass was classified as a “seriously irregular mass” and replaced with an extrapolated value, which aligns with the most recent measured values from CSRe and LEBIT. As such, the smoothness of the mass surface is confidently reestablished for 103 Sn. Here, LEBIT's mass measurement of 103 Sn enabled a significant reduction in the mass uncertainties of five parent isotopes which are now dominated by uncertainties in their respective 𝑄 values.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2025

A High-Current Pulsed Prototype Power Supply

The Accelerator Controls Operations Research Network (ACORN) project aims to modernize the accelerator control system and replace aging power supplies at Fermilab. As part of this effort, outdated RF ferrite bias power supplies will be redesigned. These power supplies are essential for tuning the resonant frequency of RF cavities by delivering programmable current outputs of up to 2500 A and voltages ranging from −10 V to +35 V. They operate at a repetition rate of 15 Hz in the Booster ring, and 1 Hz at the Main Injector ring. The power supplies utilize a bank of transistors in the linear region, connected in parallel with the load, to actively regulate the output current from a 12-pulse SCR bridge. To support this upgrade, a new bias power supply topology was developed as proof of concept. The design utilizes an IGBT Hbridge operating in Pulse Width Modulation (PWM) mode, controlled by a microcontroller. A prototype, constructed using spare components, successfully delivered an output current of 500 A at a repetition rate of 15 Hz during initial testing. The circuit's bandwidth was measured at 480 Hz, highlighting opportunities for further optimization in the controller design to achieve the target bandwidth of 2 kHz.

Bullman, Austin [ORNL]↗
DOE OSTI2020

Probing Active-Site Relocation in Cu/SSZ-13 SCR Catalysts during Hydrothermal Aging by in situ EPR Spectroscopy, Kinetic Studies, and DFT Calculations

Cu/SSZ-13 selective catalytic reduction catalysts display activity loss after mild hydrothermal aging without support degradation or loss of isolated Cu ion content. By applying electron paramagnetic resonance spectroscopy to compare hydrated, dehydrated and NH3-saturated catalysts before and after hydrothermal aging, as well as density functional theory calculations, it is found that hydrothermal aging induces Cu relocation, leading to stronger Cu-support interactions. This is particularly evidenced by ZCuOH conversion to Z2Cu, which leads to the generation of a unique structure with two Cu(II) ions positioned in a double 6-membered ring prism. The Cu(II) ions that do not undergo such dramatic changes also appear to stay closer to framework windows as evidenced by the overall increased anisotropy during EPR measurements. In situ EPR measurements under SCR conditions demonstrate that, in comparison to the fresh catalyst, higher percentages of Cu species stay as Cu(II) in the aged catalyst. This suggests that the reduction half-cycle of the SCR redox, i.e., Cu(II) ? Cu(I), becomes slower for the hydrothermally aged catalyst.

42 ENGINEERING↗
DOE OSTI2024

A high-volume resonator for L-band DNP-NMR

DNP-NMR and EPR experiments that operate at or greater than L-band (i.e., ν 0 (e – ) = 1–2 GHz) are typically limited to maximum sample volumes of several hundred µL. These experiments rely on well-known resonator designs for DNP/EPR irradiation such as the loop-gap resonator and Alderman-Grant coil, where their maximum volumes limit further application to imaging experiments and high-throughput screening beyond L-band. Herein, we demonstrate a birdcage (BC) resonator design that can accommodate several mL of sample while operating around 1.5 GHz. The sample volume is maximized by using two identical BC resonators in a stacked configuration. Simulations are used to optimize the BC design and the performance is validated experimentally with liquid-state Overhauser-DNP-NMR experiments. This BC design exploits just the parasitic capacitance of conductive rings and features no fixed tuning capacitors. An enhancement of –77 is achieved on a 10 mM 4-Amino-TEMPO in H 2 O sample for a 5 mL sample volume. Finally, the associated sample heating is minimal due to the low-E-fields generated and the large sample mass with +3.4 K when driving 100 W for several seconds.

47 OTHER INSTRUMENTATION↗