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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 55 records · Page 3
All sourcesNASA NTRSDOE OSTI
DOE OSTI2025

Metal Complex Inks for Low-Cost Photovoltaic Material Metallization

The aim of the project titled “Metal Complex Inks for Low-Cost Photovoltaic Material Metallization” was to develop new metal complex conductive inks and pastes for PV, invented and commercialized by Electroninks, Inc. (EI, Austin, TX USA, https://electroninks.com), the only global supplier and scaled-manufacturing company of these metal complex inks. These materials were developed in this work for photovoltaic applications to significantly lower the cost of metallization, improve the manufacturability, and greatly reduce metal usage, while maintaining or improving device efficiencies when compared to traditional nanoparticle-based inks. The new pastes will do so by: 1) lowering the finger resistivity and precious metals usage by printing much denser (and therefore thinner/less material) metal films than possible with traditional particle-based screen-printed pastes; 2) decreasing the firing temperature to help preserve passivation; and 3) enabling a path to move the TW-scale PV industry from Ag to other materials including Ni, Cu, and Ni/Cu alloy pastes while continuing to leverage capital investment and expertise in screen printing metallization.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2025

Summer Bat Monitoring Report for Calendar Year 2024

Bats are mammals belonging to the order Chiroptera, which means “hand-wing.” They use a thin membrane of skin stretched between their fingers to fly. All bat species known in the state of Washington are insectivorous, and each bat can consume 600 to 1,000 insects per hour while feeding. Bats typically give birth once per year to a single pup, making bat populations vulnerable to impacts and slow to recover.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2024

Summer Bat Monitoring Report for Calendar Year 2023

Bats are mammals belonging to the order Chiroptera, which means “hand-wing.” They use a thin membrane of skin stretched between their fingers to fly. All bat species known in the state of Washington are insectivorous and each bat can consume 600-1,000 insects per hour while feeding. Bats typically give birth once per year to a single pup, making bat populations vulnerable to impacts and slow to recover. Several species of bats have been documented on the Hanford Site, with nine species identified during The Nature Conservancy surveys in 1997 and 1998, and an additional seven species listed as potentially present as documented in Biodiversity Inventory and Analysis of the Hanford Site. Final Report 1994-1999 (Soll et al., 1999). Ongoing U.S. Department of Energy (DOE), Richland Operations Office (RL) acoustic surveys, including HNF-53759, Summer Bat Monitoring Report for Calendar Year 2012, have also confirmed the presence of the same nine species documented by Soll et al. (1999). An additional species, the spotted bat (Euderma maculatum), was observed roosting on the exterior of a facility by Hanford Site personnel in 2021; the species was confirmed by Hanford Site biologists via photograph (Table 1-1).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2026

Development of Advanced, Radiation Resistant, Optical-based Detector Technology for Future Experiments.

The primary objective of this project has been to advance the design of high-performance electromagnetic (EM) calorimeters for future particle physics experiments, to identify and measure the timing, position and energy of electrons, positrons and gamma rays, particularly in high-luminosity environments with intense radiation and pileup conditions. To meet such challenges, the proposed research has focused on the development of ultra-compact, radiation-hard calorimeter modules, to provide excellent timing, spatial, and energy resolution. The work aligns with the DOE’s Basic Research Needs (BRN) for High Energy Physics (HEP) Instrumentation and the research team contributes actively to the Coordinating Panel on Advanced Detectors (CPAD) RDC9 calorimetry collaboration in the USA and the European Committee on Future Accelerators (ECFA) DRD-CALO calorimetry collaboration at CERN, the European Laboratory for Particle Physics located in Geneva, Switzerland. The research builds on the RADiCAL (radiation-hard, ultra-compact) modular sampling calorimeter approach, developed by the research team, which employs dense and very bright optical materials such as LYSO:Ce scintillator plates that are interleaved with very dense tungsten plates to minimize detector size while optimizing performance. The modules are comparable in size to a human index finger, dimensionally 14 mm x 14 mm in cross section and 135 mm in length. And despite the small size, the structure is capable of providing excellent timing and energy resolution. This is facilitated through the use of specialized quartz capillaries filled with wavelength-shifting filaments, positioned at various depths along the length of a module, to collect and guide light signals to silicon photomultipliers (SiPMs) which detect and convert the optical signals to electronic signals for analysis. The primary goals of this project have been: (1) Achieve a timing resolution to σ t ≤ 30 ps for high-energy electrons and photons, important for their association with specific events produced in colliding-beam experiments and for the detection of decays-in-flight of long-lived particles. The project has achieved this goal in beam tests of a single RADiCAL module at CERN, during which a timing resolution of σ t = 27 ps was measured for electrons of energy E = 150 GeV. Based upon a mathematical fit to the data measured over a broad energy range from low energy to high energy, a resolution of σ t ≤ 18 ps has been estimated for electrons of very high (TeV) energy. From these measurements and with further expected technical improvements, the timing resolution should reach σ t ≤ 10 ps, important for searches for discovery physics in upcoming and future experiments. (2) Achieve an energy resolution of σ E / E ≤ 10% / $\sqrt{E}$. The project has yet to achieve this goal, but is close to it, having measured a value of σ E / E ≤ 15.9% / $\sqrt{E}$ using a modular array. Ultimately, the resolution goal is expected to be reached by adjustments to material thicknesses within the modules, which will improve the sampling fraction to measure more precisely the shower energy for lower energy particles. The versatility of the modular RADiCAL approach enables the testing of advanced materials, photosensors and electronics, developed in collaboration with CPAD RDC and ECFA DRD-CALO groups. The structure can distinguish electrons, positrons and gamma rays from hadrons and muons and beam-induced backgrounds, making it a valuable tool in a variety of detector environments, including future circular colliders (FCC-ee, FCC-hh) proposed for the European Laboratory for Particle Physics (CERN), the muon-collider proposed for Fermi National Accelerator Laboratory (Fermilab), and searches for new physics in beam-dump, fixed target and forward-physics experiments. And, while designed with particle physics applications in mind, the technologies developed in this project have the potential for application more broadly in particle and nuclear physics, materials science, and medical physics, underscoring the far-reaching potential of this line of instrumentation research and development.

47 OTHER INSTRUMENTATION↗
DOE OSTI2026

Nickel Interlayer for Improved Silver Complex Inks Metallization in GaAs Photovoltaic Devices

Large areas of III-V photovoltaic panels are essential to supplying operational energy for a growing demand of satellites of strategic importance to the United States military, covering a range of applications. High fabrication costs and low manufacturing throughput are key barriers to meeting the necessary supply, which can in turn jeopardize mission success. At the device level, metallization based on printing of complex metal inks has attracted significant research interest due to its potential to substantially reduce processing costs and increase throughput while achieving electrical performance comparable to those of conventional metallization schemes. For GaAs photovoltaic devices, however, reliable electrical contacting remains challenging due to the formation of an interfacial oxide layer at the metal-semiconductor interface. This oxide barrier severely limits current extraction from the PV absorber, resulting in unacceptably high contact resistance. In this study, we report the introduction of a reactive nickel (Ni) interfacial layer between the silver metal fingers and the GaAs substrate to suppress oxide formation while maintaining a low-resistance electrical interface, and show performance data from fully fabricated GaAs devices incorporating the Ni interlayer. These results demonstrate the potential of reactive Ni ink as an effective interfacial layer for improved electrical contacting in low-cost PV metallization schemes.

14 SOLAR ENERGY↗
DOE OSTI2024

1.1 eV GaInAs Cell Development for Dual-Use Solar and 1075 nm Laser Power Converters

Dual-use power converter cells can receive solar and laser power simultaneously to generate current, an application relevant to space and terrestrial industries. This study investigates two concepts of solar cells optimized for dual- use 1070 nm laser and solar power conversion, a single-junction and triple-junction cell. Because it is bandgap-tuned for a 1070 nm laser, the 1.1 eV junction is incorporated into each of the two designs, making its development key to the success of both concepts. Efficiency data for a one junction GaInAs cell demonstrates a laser conversion efficiency of 38% at 1070nm wavelength without an anti-reflection coating. However, the single-junction device requires optimization to reduce short wavelength absorption of the broad solar spectrum. In both devices, the graded buffer layers in the GaInAs cell affects the cell's performance by reducing threading dislocations in the active junction. However, the buffer in the three-junction device also acts as a lateral transport layer and so affects the fill factor depending on its sheet resistance. By varying the buffer thickness, we demonstrate a direct relationship between buffer thickness and sheet resistance reduction, while considering implications to open-circuit voltages. We also performed resistance modeling to determine the optimal grid spacing and thickness of the grid fingers to minimize losses due to sheet resistance and grid shading.

dual-use↗
DOE OSTI2024

Screen-Printed Complex Ag Inks for Si HJT Metallization

Metallization using reactive metal inks has recently attracted significant research interest due to its advantages in cost of materials and manufacturing, while still achieving performance comparable to traditional fire-through particle pastes. Here, we present for the first time the use of reactive silver (Ag) inks via industrial screen-printing and inkjet printing methods for the metallization of different Si surfaces used in tunneling oxide passivating contacts (TOPCon) and Silicon heterojunction (SHJ) solar cells. Printed Ag lines exhibit a conductivity of ~5 Mu O·cm, which is approximately 3 times that of bulk Ag (1.59 µO·cm). The printed metal has a thickness of ~0.5-1.5 Mu m, an order of magnitude smaller than the current fire-through metal finger thickness (~15 Mu m). Contact resistivity measurements of the screen-printed and inkjet-printed samples on a transparent conducting oxide (TCO) surface show a very low value of ~0.2-12 mO·cm 2. Photoluminescence images of the metallized samples demonstrate minimal surface passivation degradation compared to the non-metallized areas (?iVoc <3.5 mV). Scanning electron microscopy images (SEM) reveal the structure of the printed metals on the Si surfaces as porous but much denser than fire-through Ag by nanoparticle paste. In the final presentation, we will showcase our results of printing these reactive Ag inks on high-efficiency heterojunction and TOPCon solar cells with full-area M6 wafers. Additionally, the adhesion of these reactive Ag inks on different Si surfaces according to ASTM D3359-17, as well as the performance of solar cells after standard IEC 61215 freeze/thaw and damp heat tests, will be presented. These new metal inks show promising potential as an alternative to the currently dominant particle-based pastes, offering lower Ag consumption and lower processing temperatures without compromising performance.

heterojunction solar cells↗
DOE OSTI2024

3D printed features on nuclear fuel cladding for optimized heat transfer

A nuclear fuel cladding with improved thermomechanical properties is provided. The nuclear fuel cladding includes a double-walled construction having inner and outer hexagonal sidewalls. The inner sidewall and the outer sidewall are spaced apart from each other to form a cooling channel therebetween, and the inner sidewall surrounds a nuclear fuel and is spaced apart from the nuclear fuel by a small gap. Helical fins extend into the cooling channel to interconnect the inner sidewall and the outer sidewall. Resilient fingers extend toward the nuclear fuel through the small gap to comply with variations in the size of the nuclear fuel due to fabrication tolerances as well as thermal expansion and swelling of the nuclear fuel, for example UO 2 , when undergoing fission. The nuclear fuel cladding is formed according to an additive manufacturing process, for example laser powder bed fusion printing.

Petrie, Christian M.↗
DOE OSTI2024

Evaluation Of Elbow Exoskeleton in Glovebox Operations To Minimize Injuries – 25704

In nuclear facilities across the DOE, ergonomic injuries pose a significant occupational hazard for GB workers. Recent studies at Los Alamos National Laboratory (LANL) have revealed concerning trends in worker health, with approximately 50% of GB workers reporting musculoskeletal symptoms after 25 years of service [1]. The current GB design, largely unchanged since the 1960s, presents several ergonomic challenges including inappropriate finger lengths, nonexistent joint angles, and incorrect thumb placement. These design flaws directly contribute to conditions such as lateral epicondylitis (tennis elbow) and De Quervain's tenosynovitis which causes pain and inflammation in the tendons at the base of the thumb. These are examples of conditions caused by workers performing repetitive precision tasks [2].

Ramon, Rodrigo N. [Savannah River National Laborat↗
DOE OSTI2026

The 3D clustering of Lyman Alpha Emitters measured with DESI

We present a clustering analysis of Lyman-$α$ emitters (LAEs) using spectroscopic observations from the Dark Energy Spectroscopic Instrument (DESI) of candidates selected from the Blanco/DECam Intermediate-Band Imaging Survey (IBIS). We measure the two-point correlation function and the power spectrum, including cross-correlations with DESI quasars. Using both analytical and halo occupation distribution (HOD) simulation-based modeling, we find a linear bias of $b \sim 2.31$--$2.62$ for LAEs over the redshift range $2.26 < z < 3.41$. The analytical modeling also provides constraints on the strength of radiative transfer effects, while the HOD analysis characterizes the LAE-halo connection across multiple models. Finally, we quantify the magnitude of non-perturbative clustering effects such as Fingers of God in the LAE population, providing essential input for the accurate modeling of LAE-based cosmological analyses in forthcoming high-redshift surveys such as DESI-II.

Ebina, H. [UC, Berkeley; LBL, Berkeley] (ORCID:000↗
DOE OSTI2026

CoLoRe-2LPT: Lyman-$α$ mock catalogues for the validation of DESI cosmological analyses

The Lyman-$α$ (Ly$α$) forest has become a crucial probe for studying the large-scale structure of the universe at high redshift ($z > 2$), providing powerful constraints on Baryon Acoustic Oscillations (BAO) and the full-shape (FS) clustering of matter. As a key ingredient for upcoming BAO and FS analyses, we present a new generation of fast cosmological Ly$α$ mocks based on second-order Lagrangian perturbation theory (2LPT). These new mocks significantly improve upon previous log-normal approaches, both at accurately capturing small scale clustering and at recovering the non-linear broadening of the BAO peak. They are able to reproduce Ly$α$ statistics within $10\%$ of the latest DESI measurement; including the Ly$α$ bias and the redshift-space distortion $β$ parameter, mean transmitted flux, and 1D power spectrum. The corresponding quasar (QSO) clustering is also improved with respect to previous approaches, calibrated against high-resolution Abacus simulations, recovering the observational QSO linear bias to less than $5\%$ and improving redshift-space distortions via 2LPT velocities and the addition of Fingers-of-God effects. Furthermore, these mocks incorporate high column density systems and metal lines, allowing us to explore the effects and systematics induced by these astrophysical contaminants. This new set of mocks has been key for enhancing the modeling and validation of the DESI DR2 Ly$α$ full shape cosmological analysis. This work provides a physically motivated and computationally efficient tool for simulating current and next-generation Ly$α$ surveys and validating FS and BAO analysis.

Bernal, M.F. Ruiz-Herrera [Madrid, CIEMAT] (ORCID:↗
DOE OSTI2025

The effect of radiation damage on the light yield and uniformity of candidate plastic scintillator tiles for the CMS hadron calorimeter upgrade

A study has been performed to understand the effects of radiation damage on various plastic scintillator tiles considered for a possible upgrade of the hadron calorimeter of the CMS detector. Measurements were made with unirradiated tiles and with tiles that had been irradiated in the CMS collision hall to a dose of 44 kGy. Results are presented for the tiles of different shapes in terms of the energy spectrum, efficiency as a function of the position at which each tile was hit, as well as light yield. All the tiles showed a light reduction of up to about 50%. The tiles with the shape currently used in the CMS detector did not see increased non-uniformity of light collection, while a significant disuniformity was observed for the tiles considered as alternatives.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2025

Low-mass vector-meson production at forward rapidity in 𝑝 + 𝑝 and Au + Au collisions at $\sqrt{𝑠_{𝑁⁢𝑁}}$ = 200 GeV

The PHENIX experiment at the Relativistic Heavy Ion Collider has measured low-mass vector-meson (𝜔+𝜌 and 𝜙) production through the dimuon decay channel at forward rapidity (1.2 < |y| < 2.2) in 𝑝 + 𝑝 and Au + Au collisions at $\sqrt{𝑠_{𝑁⁢𝑁}}$ = 200 GeV. The low-mass vector-meson yield and nuclear-modification factor were measured as a function of the average number of participating nucleons, ⟨𝑁 part ⟩, and the transverse momentum 𝑝 𝑇 . These results were compared with those obtained via the kaon decay channel in a similar 𝑝 𝑇 range at midrapidity. The nuclear-modification factors in both rapidity regions are consistent within the uncertainties. A comparison of the 𝜔 + 𝜌 and 𝐽/𝜓 mesons reveals that the light and heavy flavors are consistently suppressed across both 𝑝 𝑇 and ⟨𝑁 part ⟩. Finally, in contrast, the 𝜙 meson displays a nuclear-modification factor consistent with unity, suggesting strangeness enhancement in the medium formed.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2025

Design of the ECCE detector for the Electron Ion Collider

The EIC Comprehensive Chromodynamics Experiment (ECCE) detector has been designed to address the full scope of the proposed Electron Ion Collider (EIC) physics program as presented by the National Academy of Science and provide a deeper understanding of the quark-gluon structure of matter. To accomplish this, the ECCE detector offers nearly acceptance and energy coverage along with excellent tracking and particle identification. The ECCE detector was designed to be built within the budget envelope set out by the EIC project while simultaneously managing cost and schedule risks. Finally, this detector concept has been selected to be the basis for the EIC project detector.

47 OTHER INSTRUMENTATION↗
DOE OSTI2026

Realizing the scientific program with polarized ion beams at the future BNL Electron Ion Collider

Polarized ion beams at the Electron Ion Collider (EIC) are essential to address some of the most important open questions at the twenty-first century frontiers of understanding of the fundamental structure of matter. Here, in this work, we summarize the science case and identify polarized 2 H, 3 He, 6 Li, and 7 Li ion beams as critical technology that will enable experiments which address the most important science. Furthermore, we discuss the required ion polarimetry and spin manipulation at the EIC. The current EIC accelerator design is presented. We identify a significant research and development effort across national and international laboratories and universities that is required over about a decade to realize the polarized ion beams and estimate (based on previous experience) that it will require about 20 full-time equivalent (FTE) over 10 years (or a total of about 200 FTE-years) of personnel, including graduate students, postdoctoral researchers, technicians, and engineers. Attracting, educating, and training a new generation of physicists in experimental spin techniques will be essential for the successful realization. Artificial intelligence and machine learning are seen as having significant potential for both acceleration of research and development and amplification of discovery in the optimal realization of this unique quantum technology on a cutting-edge collider. The research and development effort is synergistic with research in atomic physics and fusion energy science.

43 PARTICLE ACCELERATORS↗
DOE OSTI2025

Measurement of elliptic flow of 𝐽/𝜓 in $\sqrt{s_{NN}}$ = 200 GeV ⁢Au + Au collisions at forward rapidity

Here, we report the first measurement of the azimuthal anisotropy of 𝐽/𝜓 at forward rapidity (1.2 < |𝜂| < 2.2) in Au + Au collisions at $\sqrt{s_{NN}}$ = 200 GeV at the BNL Relativistic Heavy Ion Collider. The data were collected by the PHENIX experiment in 2014 and 2016 with integrated luminosity of 14.5 nb −1 . The second Fourier coefficient (𝑣 2 ) of the azimuthal distribution of 𝐽/𝜓 is determined as a function of the transverse momentum (𝑝𝑇) using the event-plane method. The measurements were performed for several selections of collision centrality: 0%–50%, 10%–60%, and 10%–40%. We find that in all cases the values of 𝑣 2 ⁡(𝑝 𝑇 ), which quantify the elliptic flow of 𝐽/𝜓, are consistent with zero. Within uncertainties, the results are consistent with measurements at midrapidity, indicating no significant elliptic flow of the 𝐽/𝜓 within the quark-gluon-plasma medium at collision energies of $\sqrt{s_{NN}}$ = 200 GeV.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2026

Transverse single-spin asymmetry of forward 𝜂 mesons in 𝑝 ↑ +𝑝 collisions at √𝑠 =200 GeV

Utilizing the 2012 transversely polarized proton data from the Relativistic Heavy Ion Collider at Brookhaven National Laboratory, the forward 𝜂-meson transverse single-spin asymmetry (𝐴 𝑁 ) was measured for 𝑝 ↑ +𝑝 collisions at √𝑠 =200 GeV as a function of Feynman-x (𝑥 𝐹 ) for 0.2 <|𝑥 𝐹 | <0.8 and transverse momentum (𝑝 𝑇 ) for 1.0 <𝑝 𝑇 <5.0 GeV/𝑐. Large asymmetries at positive 𝑥 𝐹 are observed (⟨𝐴 𝑁 ⟩=0.086±0.019), agreeing well with previous measurements of 𝜋 0 and 𝜂𝐴 𝑁 , but with reach to higher 𝑥 𝐹 and 𝑝 𝑇 . The contribution of initial-state spin-momentum correlations to the asymmetry, as calculated in the collinear twist-3 framework, appears insufficient to describe the data.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗