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All sources NASA NTRS DOE OSTI

DOE OSTI2025

Surface Trap Dynamics and Gamma‐Ray Detection Enhancement in Passivated FAPbBr 3 Perovskite Crystals

Perovskite‐based direct radiation detectors offer a compelling platform for room‐temperature gamma spectroscopy due to their high sensitivity, tunable optoelectronic properties, and compatibility with solution processing. While prior studies on formamidinium lead tribromide (FAPbBr 3 ) have shown that surface passivation mitigates deep trap state impact on the charge collection efficiency (CCE), the influence of surface‐based shallow traps on time‐resolved detector response remains largely unexplored. In this article, a digital signal processing (DSP) method is applied to analyze waveform rising edge dynamics in FAPbBr 3 single‐crystal detectors, identifying prompt and delayed charge collection components. Using the second derivative of the collected charge signal, the onset of shallow trap reemission is isolated, occurring 1.1 µs after carrier generation. Surface passivation suppressed deep trap states, shifting carrier occupancy toward shallower traps and extending the temporal window of delayed charge collection. This delayed contribution correlates with measurable changes in the temporal and amplitude distributions of detector events. By leveraging time‐domain filtering informed by these dynamics, a selective enhancement in signal quality and gamma peak‐to‐Compton ratio (PCR) is achieved, while preserving over 90% of photoelectric events. An improvement in the PCR to 1.80, from the original 1.09, is enabled by focusing on high collection efficiency events corresponding to reemitted carriers in the 1.1 to 3 µs range after the generation event. These results demonstrate a pathway for leveraging shallow trap dynamics to enhance spectral fidelity in time‐resolved perovskite detectors.

36 MATERIALS SCIENCE↗

DOE OSTI2025

Hydrogen-rich syngas production from the steam co-gasification of low-density polyethylene and coal refuse

Gasification provides a promising pathway for transforming waste materials into valuable products, such as fuels and chemicals. Here, this study investigates the steam co-gasification of low-density polyethylene (LDPE) and compressed thickener underflow, representative of coal refuse (CR), in a drop tube reactor. The effects of feed blend ratio (0–100 wt% LDPE) and temperature (800–1000 °C) on syngas composition, tar formation, and process efficiency are examined. The high volatility of LDPE makes it more reactive than CR but also promotes the formation of 2–7 ring aromatic tars. Increasing temperature improves carbon conversion efficiency (CCE), cold gas efficiency (CGE), and syngas yield, although the lower heating value (LHV) of syngas decreases. Hydrogen is the dominant gas product, reaching 59 vol% with the H 2 /CO molar ratio ranging from 2.27 to 4.74. Synergistic effects from alkali and alkali earth metals (AAEMs), particularly K and Ca, in CR ash enhance syngas yield by catalyzing char gasification and tar cracking. Hematite (Fe 2 O 3 ) and ash from sub-bituminous/bituminous coals are explored as tar reforming catalysts. Fe 2 O 3 achieves 100 % tar reforming efficiency, while coal ash, with a lower Fe 2 O 3 content (15 wt%), is less effective at cracking polycyclic aromatic hydrocarbons, particularly naphthalene. These findings demonstrate the flexibility of co-gasification, allowing precise tuning of syngas characteristics for specific downstream applications. Further optimization of waste-derived catalysts could enhance the economic viability of gasification in waste-to-energy processes.

01 COAL, LIGNITE, AND PEAT↗

DOE OSTI2024

Tuning Perovskites’ Hydration-Induced Chemical Expansion with Octahedral Tilt Angles

Hydration-induced strains in proton-conducting oxides compromise chemo-mechanical stability when these materials are applied in protonic ceramic electrochemical cells. Here, to develop design principles for zero-strain materials, we systematically studied the hydration coefficients of chemical expansion (CCEs) in perovskite (Sr, Ba)(Ce, Zr, Y)O 3–x solid solutions with in situ dilatometry and thermogravimetric analysis in the range of 430–630 °C. By including and decoupling a wide range of tolerance factors and lattice parameters, we were able to identify a minimum in hydration CCEs (0–0.02) at intermediate tolerance factor values (t ≈ 0.95). Conversely, despite expectations of lower CCEs in larger unit cells, no general trend in CCE versus lattice parameter was found, and opposite trends could be seen for Sr(Ce, Zr, Y)O 3–x versus Ba(Ce, Zr, Y)O 3–x separately. In situ neutron diffraction (ND) enabled atomistic insight. Upon decreasing t, chemical strain anisotropy increased, but this trend did not match the U-shaped dependence of macroscopic CCEs on t. Instead, perovskites with intermediate t, hosting intermediate octahedral tilt angles in the nominally dry state, underwent the largest change in the B–O–B angles during hydration. Accommodating hydration through decreasing B–O–B angles is beneficial because it does not result in large lattice parameter changes. We propose an intermediate tolerance factor as a simple structural descriptor to enable near-zero hydration strains in proton-conducting perovskites.

36 MATERIALS SCIENCE↗

DOE OSTI2025

Packaging HEP Heterogeneous Mini-apps for Portable Benchmarking and Facility Evaluation on Modern HPCs

High Energy Physics (HEP) experiments are making increasing use of GPUs and GPU dominated High Performance Computer facilities. Both the software and hardware of these systems are rapidly evolving, creating challenges for experiments to make informed decisions as to where they wish to devote resources. In its first phase, the High Energy Physics Center for Computational Excellence (HEP-CCE) produced portable versions of a number of heterogeneous HEP mini-apps, such as p2r, FastCaloSim, Patatrack and the WireCell Toolkit, that exercise a broad range of GPU characteristics, enabling cross platform and facility benchmarking and evaluation. However, these miniapps still require a significant amount of manual intervention to deploy on a new facility. We present our work in developing turn-key deployments of these mini-apps, where by means of containerization and automated configuration and build techniques such as Spack, we are able to quickly test new hardware, software, environments and entire facilities with minimal user intervention, and then track performance metrics over time.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

DOE OSTI2025

Impact of proton irradiation on 4H-SiC Low Gain Avalanche Detectors (LGADs)

Silicon carbide (SiC) particle detectors have the potential to provide time resolutions and robust performance in extreme environments which exceed that of silicon detectors. In this work 4H-SiC low gain avalanche detectors (LGADs) and complementary PiN diodes were irradiated with 2.5 GeV protons at fluences up to 3.33 × 10 14 p/cm 2 . The electrostatic performance of both irradiated and non-irradiated devices was evaluated using I-V and C-V measurements. Moreover, charge collection measurements using α particles were also conducted. SiC LGADs displayed a loss in rectification, high ON-state resistances >10 10 Ω-cm 2 , and the complete removal of gain when exposed to the highest proton fluence. Additionally, the reductions in capacitance and OFF-state current pointed to compensation of the gain layer as a gain reducing mechanism. The introduction of radiation-induced defects also hinders carrier acceleration, which reduces impact ionization and further gain reduction. LGADs exposed to a fluence of 1 × 10 14 p/cm 2 experienced a partial recovery in gain (originally having a value of ∼ 2) with a value of ∼ 1.65 when applying a bias of 500 V. Charge trapping was also seen in the reduction of charge collection efficiency (CCE) to ∼ 65% for the PiN diode. However, despite the reduction in device performance, the demonstration of a measurable signal after irradiation points to the potential of SiC LGAD detectors for future high energy physics applications.

43 PARTICLE ACCELERATORS↗

DOE OSTI2024

Venado acceptance: results and tips [Slides]

Nvidia compiler support is not available through cray-mpich/compiler wrapper interface. Adjust CMAKE files to use the correct COMPILER_ID in conditionals and explicit variables to package flags. Use pinned host memory in cray-libsci_acc and cublasXt calls. Set a large blockDim for cublasXt calls. Try MPS and/or explicit numactl binding if performance is lackluster. Use CRAY_MALLOPT_OFF=1 if unexpected OOM errors appear using cce. Use MPICH_SMP_SINGLE_COPY_MODE=CMA for xpmem issues. Use MPICH_OPT_THREAD_SYNC=0 for MPI_THREAD issues. Poor CUDA-aware MPI performance remains an issue.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2024

An Advanced Pretreatment/Anaerobic Digestion (APAD) Technology for Increased Conversion of Sewage Sludge to Bio-natural Gas in Small-scale Wastewater Plants of less than Five tons Sewage Sludge a Day

The problem today of energy production from sewage sludge at small-scale is that conventional Anaerobic Digestion (AD) as used today at Wastewater Treatment Facilities (WWTF) produces too little energy for warrant use of the biogas. It further leaves 50% or more of the waste behind after the treatment. To overcome this problem, we proposed a novel concept based on Advanced Wet Oxidation & Steam Explosion (AWOEx) of the recalcitrant parts of sewage sludge left behind after AD. We further suggest upgrading biogas to renewable natural gas (RNG) using gaseous fermentation of biogas with hydrogen added by a new methanogen. Overall, the DOE funded Advanced Pretreatment & Anaerobic digestion (APAD) project showed significant improvements over current practice. The project demonstrated that AWOEx followed by AD significantly enhanced the carbon conversion efficiency from 37% to 62%, an increase of 68%. This is far higher than the metric for the specific FOA of an increase of 50%. Besides, the project showed high efficiency of our biological conversion of biogas into RNG when using a new isolate of Methanothermobacter wolfeii resulting in a 100% increased production of a refined biogas with maximum 5% CO2. With both AWOEx pretreatment and biogas upgrading, the project showed a CCE of ca. 83%, far higher than any previous work on sewage sludge. Besides over 200% higher amount of energy in the form of RNG, the APAD concept will reduce disposal cost due to significant reduction in the concentration of final sludge product after APAD. The APAD technology can operate as a bolt-on to a conventional AD plant for improving conversion of the residual organics after AD as done in this DOE project. It can further be implemented as a stand-alone process with AWOEx followed by AD for WWTF’s currently operating without AD.

09 BIOMASS FUELS↗

DOE OSTI2025

Corral Summit Pumped Storage Hydropower Hybrid: Site Suitability Assessment

In 2024, Idaho National Laboratory (INL) and Pacific Northwest National Laboratory (PNNL) initiated a technical-assistance project to support Cat Creek Energy, LLC, (CCE) in evaluating site suitability for the proposed Corral Summit Pumped Storage Hydropower (PSH) project in south-central Idaho near Mackay Reservoir. The Corral Summit facility incorporates battery storage and photovoltaic (PV) solar arrays in a Trybrid configuration to deliver large-volume long-duration (LVLD) storage solutions for rural electric cooperatives in eastern Idaho. The evaluation process focused on determining the most-suitable location for the upper reservoir of the PSH system, guided by a comprehensive assessment framework spanning multiple categories, including physical characteristics, environmental constraints, building infrastructure, regulatory constraints, cultural resources and sensitivity, social factors, and power market and grid integration. Each site was analyzed based on a ranking scale (0–1), which scores ranging from “severely disfavored” to “highly favored,” allowing detailed comparisons of site-specific conditions. Categories such as hydraulic head, utilities corridor, land ownership, and transmission-grid limitations emerged as key contributors to the overall assessment. Site 2 (Idaho Trust) demonstrated a slight advantage over Site 1 (Bureau of Land Management) primarily due to favorable outcomes in regulatory constraints, building infrastructure, and power-market integration. However, Site 1 outperformed Site 2 in factors related to physical characteristics and social factors. The report emphasizes the need for further evaluation of both sites before clear determination of which site is preferred, due to the limited information available on either site at the time of this report. Key areas of evaluation to clearly define the preferred site are ecological impacts, cultural-resource surveys, and economic-feasibility assessments. For successful project execution, recommended follow-up actions include seismic and geotechnical surveys, groundwater and habitat monitoring, regulatory reviews of water rights and right-of-way agreements, cultural engagement with local tribal governments, and enhanced stakeholder strategies. These efforts will ensure the Corral Summit Trybrid facility meets local energy needs while balancing environmental, social, and regulatory responsibilities.

13 - HYDRO ENERGY↗

DOE OSTI2025

Corral Summit Pumped Storage Hydropower Hybrid Site Suitability Assessment (Rev.1)

13 - HYDRO ENERGY↗

DOE OSTI2025

Packaging HEP Heterogeneous Mini-apps for Portable Benchmarking and Facility Evaluation on Modern HPCs

High Energy Physics (HEP) experiments are making increasing use of GPUs and GPU dominated High Performance Computer facilities. Both the software and hardware of these systems are rapidly evolving, creating challenges for experiments to make informed decisions as to where they wish to devote resources. In its first phase, the High Energy Physics Center for Computational Excellence (HEP-CCE) produced portable versions of a number of heterogeneous HEP mini-apps, such as \ptor, FastCaloSim, Patatrack and the WireCell Toolkit, that exercise a broad range of GPU characteristics, enabling cross platform and facility benchmarking and evaluation. However, these mini-apps still require a significant amount of manual intervention to deploy on a new facility. We present our work in developing turn-key deployments of these mini-apps, where by means of containerization and automated configuration and build techniques such as Spack, we are able to quickly test new hardware, software, environments and entire facilities with minimal user intervention, and then track performance metrics over time.

Atif, Mohammad [Brookhaven] (ORCID:000000026889770↗

NASA NTRS1980

Design of a modular digital computer system

A Central Control Element (CCE) module which controls the Automatically Reconfigurable Modular System (ARMS) and allows both redundant processing and multi-computing in the same computer with real time mode switching, is discussed. The same hardware is used for either reliability enhancement, speed enhancement, or for a combination of both.

Source record↗

NASA NTRS1982

Tracking and orbit determination strategies for the AMPTE mission set

The three-spacecraft AMPTE mission set to be Delta-launched in August 1984 will become the first highly-elliptical Earth orbiters to be supported by the Deep Space Network. Orbit accuracies for the transponder-equipped CCE and IRM spacecraft are defined using coherent doppler and range, non-coherent doppler, and angles. Required navigation accuracies for both spacecraft are met using coherent doppler, and while the use of range enhances the achievable accuracy, it is not a required radio metric data type. Use of non-coherent doppler and angles shows that the IRM navigation accuracy requirements can also be met using listen-only antennas, although this requires an accurate estimate of the doppler bias.

Frauenholz, R. B.↗

NASA NTRS1982

Power, thermal, and attitude control design interactions of the CCE/AMPTE spacecraft

The power, thermal and attitude control interactions of the CCE spacecraft and the design compromises resulting from these interactions are described. These compromises result from the conflict between the plane change maneuver requirements and the final on station requirements. The resolution of these conflicts to arrive at an acceptable final design, is given and the resulting power, thermal and attitude control systems are described in some detail.

Wingate, C. A., Jr.↗

NASA NTRS1985

Some design characteristics of the AMPTE turn and orbit change maneuvers

The maneuvers carried out by the Active Magnetospheric Particle Tracer Explorers (AMPTE) including the Charge Composition Explorer (CCE) and the Ion Release Module (IRM) spacecraft are analyzed. Analytic and graphical methods are developed in order to carry out sensitivity analyses that helped design the nominal maneuvers, by taking into account errors in burn initiating time, motor performance, and spin axis pointing. A tradeoff analysis between errors in timing and Delta V magnitude is shown for the IRM orbit transfer, and a technique that allows for the determination of the attitude of spinner spacecraft by way of the observed Doppler shift resulting from an unbalanced turn is investigated.

Kechichian, J. A.↗

NASA NTRS1985

The AMPTE Charge Composition Explorer science data system

The instrument complement on all three Active Magnetospheric Particle Tracer Explorer (AMPTE) spacecraft is devoted to the conduction of the unified measurements which are required to achieve the scientific aims. A single science data base for each spacecaft has, therefore, been established with the objective to facilitate unified analysis. The data are kept in Science Data Centers in the U.S., West Germany, and the United Kingdom. The Science Data Center dedicated to the Charge Composition Explorer (CCE) is located at the Applied Physics Laboratory of Johns Hopkins University where it was developed. The present paper is concerned with aspects of the computing center's design, development and operations.

Holland, B. B.↗

NASA NTRS1985

The AMPTE/CCE Hot-Plasma Composition Experiment (HPCE)

The Hot-Plasma Composition Experiment (HPCE) on the AMPTE-CCE spacecraft consists of an energetic ions-mass spectrometer and an electron background-environment monitor (EBEM). The mass spectrometer covers the entire mass per charge range from below 1 to greater than 150 amu/e and the energy per charge range from 0 eV/e (spacecraft potential) to 17 keV/e. The EBEM measures electrons between 50 eV and 25 keV in eight broad energy bands. The ion and electron data are processed into color spectrogram formats for the data pool.

Shelley, E. G.↗

NASA NTRS1985

AMPTE/CCE magnetic field studies of the September 4, 1984 storm

The AMPTE/CCE (active magnetospheric particle tracer explorer/charge composition explorer) magnetic-field observations acquired during the September 4, 1984 geomagnetic storm are described. The observations are used to determine magnetospheric regions and boundaries and are also used as the primary index of the development, evolution, and distribution of the ring current. The results of an analysis of the observations are presented. It is shown that a magnetic compression observed inside the magnetosphere by CCE and outside by ISEE-2 is interpreted as a sudden impulse. From an estimation of magnetopause normals at each crossing, it is concluded that the magnetic variations that occur are due to a contraction and expansion of the entire magnetosphere. Local magnetic-field depressions are observed during two inbound dusk passes, confirming that the ring current never developed in the dawn sector.

Potemra, T. A.↗

NASA NTRS1985

AMPTE/CCE energetic particle composition measurements during the September 4, 1984 magnetic storm

The results of measurements for the magnetic-storm period of September 4-7, 1984 from the medium-energy particle analyzer (MEPA) on the CCE spacecraft are presented. It is shown that within L-shells of about 2.5 to 5 in the dusk sector near the equatorial plane, the enhancement factor in the fluxes for the CNO group is greater than that of helium, which is greater than that of protons. The flux ratios of helium and CNO over all ions at the same total energy show considerable increases in the same L-shell ranges. For the particle population measured by MEPA, a local current-density enhancement of about 0.5 nA/sq m is found over the L range of 3.5 to 6 during the magnetic storm. It is found that the total current density is dominated by the pressure-gradient current of the protons.

Mcentire, R. W.↗