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All sourcesNASA NTRSDOE OSTI
DOE OSTI2026

Data for "Plasmon-driven exciton formation in a non-equilibrium Fermi liquid"

This repository contains source data for key plots presented in the manuscript "Plasmon-driven exciton formation in a non-equilibrium Fermi liquid." Experimental data that was analyzed in Igor Pro 8 are presented as the .pxp files used to generate individual sub-plots. Electronic spectral function calculations are provided as .txt files, in which consecutive rows refer to the meshgrid x coordinate, y coordinate, spectral function (and, where relevant, axis-projected local angular momentum). We additionally include the Wannier model and DFT-obtained bulk band structure on which the Wannier model was based. Files are named as the number of the figure in the manuscript to which they correspond, with additional details included where necessary. Details of file names: 2a_DOS_Lxz_Ek_KGM_40layer_xnum_800kpt_tot.txt: Density of states, xz-axis projected local orbital angular momentum, for 800 points along the K-Gamma-M path, for a 40-layer model. 2c_composite_y.pxp: ARPES (angle-resolved photoemission spectroscopy) spectra along the ky axis, including both a scan near the Fermi level and a scan at high kinetic energies. 2d_LCP_RCP_diff_Sect_20K.pxp: difference between ARPES constant energy cuts at T=20 K at E0 + 0.23 eV taken with left- and right-circularly polarized photons. The polarization-integrated intensity at the constant energy cut is also included. 2e_DOS_L45_E11pt79_m0pt25to0pt25_xnum_800kpt_tot.txt: Density of states, xz-projected local orbital angular momentum, and corresponding k-points in two dimensions from ab-initio electronic structure calculations for a constant-energy cut. 3a_[x]_[y]ps: ARPES cut under excitation at a fluence of x uJ/cm2, measured y ps after photoexcitation. Measurements were performed at 9 K. 3b_[x]: Energy distribution curves under excitation at a fluence x uJ/cm2 at selected delay times after photoexcitation. 4a_ImSigma_vs_temperature.pxp: Imaginary self energy (extracted from ARPES linewidths) at different energies above E0 for selected lattice temperatures. 4b_EELS_lowE.pxp: Electron energy loss spectrum over a low energy range 5b_diff_55m15.pxp: Difference between momentum-integrated Tr-ARPES traces at 55 uJ/cm2 and 15 uJ/cm2 photoexcitation. Time-dependent intensity at each energy level has been normalized to a maximum of 1 for each individual fluence prior to subtraction. 5d_invtau_at_EX_vs_fluence.pxp: decay rate at a specified energy EX for different excitation fluences, from single exponential fits. NOTE: Analyses based on the Wannier model presented here should cite both the associated Article and this dataset. For all other files in the repository, citing the dataset alone is sufficient.

Acharya, Rishi [University of Illinois] (ORCID:000↗
DOE OSTI2014

3C 220.3: A radio galaxy lensing a submillimeter galaxy

Herschel Space Observatory photometry and extensive multiwavelength follow-up have revealed that the powerful radio galaxy (PRG) 3C 220.3 at z = 0.685 acts as a gravitational lens for a background submillimeter galaxy (SMG) at z = 2.221. At an observed wavelength of 1 mm, the SMG is lensed into three distinct images. In the observed near infrared, these images are connected by an arc of ∼1''.8 radius forming an Einstein half-ring centered near the radio galaxy. In visible light, only the arc is apparent. 3C 220.3 is the only known instance of strong galaxy-scale lensing by a PRG not located in a galaxy cluster and therefore it offers the potential to probe the dark matter content of the radio galaxy host. Lens modeling rejects a single lens, but two lenses centered on the radio galaxy host A and a companion B, separated by 1''.5, provide a fit consistent with all data and reveal faint candidates for the predicted fourth and fifth images. The model does not require an extended common dark matter halo, consistent with the absence of extended bright X-ray emission on our Chandra image. The projected dark matter fractions within the Einstein radii of A (1''.02) and B (0''.61) are about 0.4 ± 0.3 and 0.55 ± 0.3. The mass to i-band light ratios of A and B, M/L{sub i}∼8±4 M{sub ⊙} L{sub ⊙}{sup −1}, appear comparable to those of radio-quiet lensing galaxies at the same redshift in the CfA-Arizona Space Telescope LEns Survey, Lenses Structure and Dynamics, and Strong Lenses in the Legacy Survey samples. The lensed SMG is extremely bright with observed f(250 μm) = 440 mJy owing to a magnification factor μ ∼ 10. The SMG spectrum shows luminous, narrow C IV λ1549 Å emission, revealing that the SMG houses a hidden quasar in addition to a violent starburst. Multicolor image reconstruction of the SMG indicates a bipolar morphology of the emitted ultraviolet (UV) light suggestive of cones through which UV light escapes a dust-enshrouded nucleus.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2020

Characterization of Extreme Ultraviolet Coatings

This project, Characterization of Extreme Ultraviolet Coatings, focused on the development of novel high reflectance coatings for EUV mirrors. A variety of samples and material systems were created and analyzed. Tests at LBNL’s Center for X-Ray Optics (CXRO) demonstrated improved relative performance between the project’s material system and the CXRO reference sample.

36 MATERIALS SCIENCE↗
NASA NTRS1982

Simultaneous optical and X-ray bursts from 4U/MXB 1636-53

Methods of obtaining information about the geometry of X-ray burster systems from simultaneous optical and X-ray observations are discussed, and such simultaneous observations of 4U/MXB 1636-53 are reported. The physical idea of an optical burst being due to reprocessing of an X-ray burst in material in the vicinity of the compact object is discussed. The resulting modification of the X-ray burst signal is described in terms of an optical response function. Delay and smearing due to radiative processes are discussed along with those due to the geometry. For 4U/MXB 1636-53, the estimated delay is 2.5 seconds, the smearing is less than four seconds, and the maximum temperature of the reprocessing region is about 75,000 K. The projected area of the reprocessing region is about 6 x 10 to the 21st square cm. The neutron star is about 1.4 solar masses, the radius of the accretion disk is greater than 1.5 lt-sec, and the mass of the Roche lobe filling companion star is less than 2.0 solar masses, corresponding to a binary period between about one and ten hours.

Pedersen, H.↗
NASA NTRS1997

NASA X-34 Technology in Motion

The X-34 technology development program is a joint industry/government project to develop, test, and operate a small, fully-reusable hypersonic flight vehicle. The objective is to demonstrate key technologies and operating concepts applicable to future reusable launch vehicles. Integrated in the vehicle are various systems to assure successful completion of mission objectives, including the Main Propulsion System (MPS). NASA-Marshall Space Flight Center (MSFC) is responsible for developing the X-34's MPS including the design and complete build package for the propulsion system components. The X-34 will be powered by the Fastrac Engine, which is currently in design and development at NASA-MSFC. Fastrac is a single-stage main engine, which burns a mixture of liquid oxygen (LOX) and kerosene(RP-1). The interface between the MPS and Fastrac engine are critical for proper system operation and technologies applicable to future reusable launch vehicles. Deneb's IGRIP software package with the Dynamic analysis option provided a key tool for conducting studies critical to this interface as well as a mechanism to drive the design of the LOX and RP-1 feedlines. Kinematic models were created for the Fastrac Engine and the feedlines for various design concepts. Based on the kinematic simulation within Envision, design and joint limits were verified and system interference controlled. It was also critical to the program to evaluate the effect of dynamic loads visually, providing a verification tool for dynamic analysis and in some cases uncovering areas that had not been considered. Deneb's software put the X-34 technology in motion and has been a key factor in facilitating the strenuous design schedule.

Beech, Geoffrey↗
DOE OSTI2018

Towards in-situ high precision local material velocity measurements in lattice materials under dynamic compression

The study of dynamic compression of materials requires high precision spatial and temporal resolution to infer the material state at any given time. In ultra-fast imaging experiments such as those performed at the Dynamic Compression Sector at the Advanced Photon Source, the current CCD frame rate is less than the X-ray pulse rate necessitating that 4 CCDs be used to image a single scintillator screen to obtain the same projection of transmitted or diffracted beam at time intervals synchronized with the X-ray beam. The use of multiple-camera setups is often employed for a variety of reasons including enhancing the temporal resolution through interleaving frames or increasing the number of viewpoints, for example. Physical corrections are made to have each CCD approximately viewing the same field of view, however we present corrections that can be made after the data collection to further refine and be able to compare movements and changes in the sample between independent CCDs. These software corrections enable higher precision and higher fidelity comparison of position changes due to sample deformation. Furthermore, we present a method to correct images (or frames) as a demonstration toward high fidelity displacement measurements in these types of ultra-fast multi-camera setup experiments.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Reference Model 2 Full Scale Geometry (RM2: River Current Turbine)

Contains the Reference Model 2 (RM2) full scale geometry files of the River Current Turbine, developed by the Reference Model Project (RMP). These full scale geometry files are saved as SolidWorks assembly, IGS, X_T, and STEP files, and require a CAD program to view. This data was generated upon completion of the project on September 30, 2014. The Reference Model Project (RMP), sponsored by the U.S. Department of Energy (DOE), was a partnered effort to develop open-source MHK point designs as reference models (RMs) to benchmark MHK technology performance and costs, and an open-source methodology for design and analysis of MHK technologies, including models for estimating their capital costs, operational costs, and levelized costs of energy. The point designs also served as open-source test articles for university researchers and commercial technology developers. The RMP project team, led by Sandia National Laboratories (SNL), included a partnership between DOE, three national laboratories, including the National Renewable Energy Laboratory (NREL), Pacific Northwest National Laboratory (PNNL), and Oak Ridge National Laboratory (ORNL), the Applied Research Laboratory of Penn State University, and Re Vision Consulting. Reference Model 2 (RM2) is a variable speed dual-rotor cross-flow river turbine that is deployed at the waters surface. It was designed for deployment at a reference site modeled after a reach in the Mississippi River near Baton Rouge, Louisiana. The rotors are anchored to a two-pontoon vessel platform. Surface deployment of the turbine minimizes the handling requirements during deployment and recovery and reduces overall costs for all O&M activities, including allowing for easy access to the power conversion chain (PCC). The design (two rotors per platform) also reduces the environmental footprint and associated environmental compliance costs.

16 TIDAL AND WAVE POWER↗
DOE OSTI2014

Reference Model 4 Full Scale Geometry (RM4: Ocean Current Turbine)

Contains the Reference Model 4 (RM4) full scale geometry files of the Ocean Current Turbine, developed by the Reference Model Project (RMP). These full scale geometry files are saved as SolidWorks assembly, IGS, X_T, and STEP files, and require a CAD program to view. This data was generated upon completion of the project on September 30, 2014. The Reference Model Project (RMP), sponsored by the U.S. Department of Energy (DOE), was a partnered effort to develop open-source MHK point designs as reference models (RMs) to benchmark MHK technology performance and costs, and an open-source methodology for design and analysis of MHK technologies, including models for estimating their capital costs, operational costs, and levelized costs of energy. The point designs also served as open-source test articles for university researchers and commercial technology developers. The RMP project team, led by Sandia National Laboratories (SNL), included a partnership between DOE, three national laboratories, including the National Renewable Energy Laboratory (NREL), Pacific Northwest National Laboratory (PNNL), and Oak Ridge National Laboratory (ORNL), the Applied Research Laboratory of Penn State University, and Re Vision Consulting. Reference Model 4 (RM4) is a "flying-wing" ocean current turbine concept intended for deployment in the Gulf Stream off the southeast coast of Florida. The RM4 device has four rotors, with a rotorless center nacelle housing the power electronics, attached on a straight wing 120 m long. The device is designed to be submerged ~50 m below the surface and is moored to the seabed. The RM4 uses buoyancy within the wing and the five nacelles to maintain its position in the water column. Each rotor has a diameter of 33 m and has a 1-MW power rating, yielding a total device rated power of 4 MW. The rotors on the left and right side of the wing rotate in opposite directions in order to balance the torque applied to the device. The rotorless center nacelle housing the power electronics serves to condition the power generated by the rotors before it is delivered to the grid.

16 TIDAL AND WAVE POWER↗
NASA NTRS2004

Explanation Constraint Programming for Model-based Diagnosis of Engineered Systems

We can expect to see an increase in the deployment of unmanned air and land vehicles for autonomous exploration of space. In order to maintain autonomous control of such systems, it is essential to track the current state of the system. When the system includes safety-critical components, failures or faults in the system must be diagnosed as quickly as possible, and their effects compensated for so that control and safety are maintained under a variety of fault conditions. The Livingstone fault diagnosis and recovery kernel and its temporal extension L2 are examples of model-based reasoning engines for health management. Livingstone has been shown to be effective, it is in demand, and it is being further developed. It was part of the successful Remote Agent demonstration on Deep Space One in 1999. It has been and is being utilized by several projects involving groups from various NASA centers, including the In Situ Propellant Production (ISPP) simulation at Kennedy Space Center, the X-34 and X-37 experimental reusable launch vehicle missions, Techsat-21, and advanced life support projects. Model-based and consistency-based diagnostic systems like Livingstone work only with discrete and finite domain models. When quantitative and continuous behaviors are involved, these are abstracted to discrete form using some mapping. This mapping from the quantitative domain to the qualitative domain is sometimes very involved and requires the design of highly sophisticated and complex monitors. We propose a diagnostic methodology that deals directly with quantitative models and behaviors, thereby mitigating the need for these sophisticated mappings. Our work brings together ideas from model-based diagnosis systems like Livingstone and concurrent constraint programming concepts. The system uses explanations derived from the propagation of quantitative constraints to generate conflicts. Fast conflict generation algorithms are used to generate and maintain multiple candidates whose consistency can be tracked across multiple time steps.

Narasimhan, Sriram↗
DOE OSTI2014

TU-A-9A-09: Proton Beam X-Ray Fluorescence CT

Purpose: To evaluate x-ray fluorescence computed tomography induced with proton beams (pXFCT) for imaging of gold contrast agent. Methods: Proton-induced x-ray fluorescence was studied by means of Monte Carlo (MC) simulations using TOPAS, a MC code based on GEANT4. First, proton-induced K-shell and L-shell fluorescence was studied as a function of proton beam energy and 1) depth in water and 2) size of contrast object. Second, pXFCT images of a 2-cm diameter cylindrical phantom with four 5- mm diameter contrast vials and of a 20-cm diameter phantom with 1-cm diameter vials were simulated. Contrast vials were filled with water and water solutions with 1-5% gold per weight. Proton beam energies were varied from 70-250MeV. pXFCT sinograms were generated based on the net number of gold K-shell or L-shell x-rays determined by interpolations from the neighboring 0.5keV energy bins of spectra collected with an idealized 4π detector. pXFCT images were reconstructed with filtered-back projection, and no attenuation correction was applied. Results: Proton induced x-ray fluorescence spectra showed very low background compared to x-ray induced fluorescence. Proton induced L-shell fluorescence had a higher cross-section compared to K-shell fluorescence. Excitation of L-shell fluorescence was most efficient for low-energy protons, i.e. at the Bragg peak. K-shell fluorescence increased with increasing proton beam energy and object size. The 2% and 5% gold contrast vials were accurately reconstructed in K-shell pXFCT images of both the 2-cm and 20-cm diameter phantoms. Small phantom L-shell pXFCT image required attenuation correction and had a higher sensitivity for 70MeV protons compared to 250MeV protons. With attenuation correction, L-shell pXFCT might be a feasible option for imaging of small size (∼2cm) objects. Imaging doses for all simulations were 5-30cGy. Conclusion: Proton induced x-ray fluorescence CT promises to be an alternative quantitative imaging technique to the commonly considered XFCT imaging with x-ray beams.

60 APPLIED LIFE SCIENCES↗
NASA NTRS1983

A high energy resolution experiment in the hard X-ray range

The Low Energy Gamma-Ray Spectrometer (LEGS), a joint project among NASA/GSFC, CEN-SACLAY, and Rice University, is designed to perform fine energy resolution measurements of astrophysical sources. In its low energy configuration (20-800 keV energy range) the instrument uses three planar detectors (effective area of 53 sq cm) surrounded by a combination of passive Fe and active NaI for shielding and collimation (FOW of about 5 x 10 deg FWHM). In a typical one-day balloon flight, LEGS sensitivity limit (3 sigma) for narrow line features is not greater than about 0.0003 ph/sq cm s (at 100 kev).

Paciesas, W.↗
DOE OSTI2022

Sub-10 second fly-scan nano-tomography using machine learning

Abstract X-ray computed tomography is a versatile technique for 3D structure characterization. However, conventional reconstruction algorithms require that the sample not change throughout the scan, and the timescale of sample dynamics must be longer than the data acquisition time to fulfill the stable sample requirement. Meanwhile, concerns about X-ray-induced parasite reaction and sample damage have driven research efforts to reduce beam dosage. Here, we report a machine-learning-based image processing method that can significantly reduce data acquisition time and X-ray dose, outperforming conventional approaches like Filtered-Back Projection, maximum-likelihood, and model-based maximum-a-posteriori probability. Applying machine learning, we achieve ultrafast nano-tomography with sub-10 second data acquisition time and sub-50 nm pixel resolution in a transmission X-ray microscope. We apply our algorithm to study dynamic morphology changes in a lithium-ion battery cathode under a heating rate of 50 o C min −1 , revealing crack self-healing during thermal annealing. The proposed method can be applied to various tomography modalities.

36 MATERIALS SCIENCE↗
NASA NTRS1992

ROSAT implementation of a proposed multi-mission x ray data format

Until recently little effort has been made to ensure that data from X-ray telescopes are delivered in a format that reflects the common characteristics that most X-ray datasets share. Instrument-specific data-product design hampers the comparison of X-ray measurements made by different detectors and should be avoided whenever possible. The ROSAT project and the High Energy Astrophysics Science Archive Research Center (HEASARC) have defined a set of X-ray data products ('rationalized files') for ROSAT data that can be used for distribution and archiving of data from other X-ray missions. This set of 'rationalized files' has been defined to isolate instrument-independent and instrument-specific quantities using standards FITS constructs to ensure portability. We discuss the usage of the 'rationalized files' by ROSAT for data distribution and archiving, with particular emphasis on discrimination between instrument-independent and instrument-specific quantities, and discuss application of this format to data from other X-ray missions.

Corcoran, M.↗
DOE OSTI2023

Ultra low background Micromegas detectors for BabyIAXO solar axion search

Abstract The International AXion Observatory (IAXO) is a large scale axion helioscope that will look for axions and axion-like particles produced in the Sun with unprecedented sensitivity. BabyIAXO is an intermediate experimental stage that will be hosted at DESY (Germany) and that will test all IAXO subsystems serving as a prototype for IAXO but at the same time as a fully-fledged helioscope with potential for discovery.One of the crucial components of the project is the ultra-low background X-ray detectors that will image the X-ray photons produced by axion conversion in the experiment. The baseline detection technology for this purpose are Micromegas (Microbulk) detectors. We will show the quest and the strategy to attain the very challenging levels of background targeted for BabyIAXO that need a multi-approach strategy coming from ground measurements, screening campaigns of components of the detector, underground measurements, background models, in-situ background measurements as well as powerful rejection algorithms. First results from the commissioning of the BabyIAXO prototype will be shown.

Instruments & Instrumentation↗
DOE OSTI2022

The alignment between brightest cluster galaxies and host clusters

The alignment between the brightest cluster galaxies (BCGs) and host clusters can reveal the mystery of the formation and evolution of galaxy clusters. We measure cluster orientations in optical based on the projected distribution of member galaxies and in X-ray by fitting the morphology of intracluster medium (ICM). Cluster orientations determined in the two wavelengths are generally consistent. The orientation alignment between BCGs and host clusters is confirmed and more significant than in previous works. We find that BCGs are more aligned with cluster orientations measured in X-ray than those from optical data. Clusters with a brighter BCG generally show a stronger alignment. We argue that the detected redshift evolution of the alignment is probably caused by observational bias rather than intrinsic evolution. The alignment is not related to the ellipticity of BCGs, and the richness, ellipticity, and dynamical state of host clusters. As a result, the strong alignment between BCGs and the morphology of ICMs may be the consequence of the co-evolution between the central massive galaxy and host clusters.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2015

SU-E-I-08: Investigation of Deconvolution Methods for Blocker-Based CBCT Scatter Estimation

Purpose: To investigate whether deconvolution methods can improve the scatter estimation under different blurring and noise conditions for blocker-based scatter correction methods for cone-beam X-ray computed tomography (CBCT). Methods: An “ideal” projection image with scatter was first simulated for blocker-based CBCT data acquisition by assuming no blurring effect and no noise. The ideal image was then convolved with long-tail point spread functions (PSF) with different widths to mimic the blurring effect from the finite focal spot and detector response. Different levels of noise were also added. Three deconvolution Methods: 1) inverse filtering; 2) Wiener; and 3) Richardson-Lucy, were used to recover the scatter signal in the blocked region. The root mean square error (RMSE) of estimated scatter serves as a quantitative measure for the performance of different methods under different blurring and noise conditions. Results: Due to the blurring effect, the scatter signal in the blocked region is contaminated by the primary signal in the unblocked region. The direct use of the signal in the blocked region to estimate scatter (“direct method”) leads to large RMSE values, which increase with the increased width of PSF and increased noise. The inverse filtering is very sensitive to noise and practically useless. The Wiener and Richardson-Lucy deconvolution methods significantly improve scatter estimation compared to the direct method. For a typical medium PSF and medium noise condition, both methods (∼20 RMSE) can achieve 4-fold improvement over the direct method (∼80 RMSE). The Wiener method deals better with large noise and Richardson-Lucy works better on wide PSF. Conclusion: We investigated several deconvolution methods to recover the scatter signal in the blocked region for blocker-based scatter correction for CBCT. Our simulation results demonstrate that Wiener and Richardson-Lucy deconvolution can significantly improve the scatter estimation compared to the direct method.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Understanding and Controlling Conductivity Transitions in Correlated Solids: Spectroscopic Studies of Electronic Structure in Vanadates (Final Report)

This research project is focused on synchrotron radiation based x-ray spectroscopic studies of the metal to insulator transition in vanadium oxides. In doing so, we developed a fundamental understanding of the origins of conductivity transitions in correlated electron materials. Conductivity transitions can be driven by external and internal mechanisms, including electric and magnetic fields, chemical doping, defects, disorder, pressure, dimensionality, and temperature. Vanadium oxides, and vanadium dioxide in particular, display particularly complex electronic phenomena. Binary vanadium oxides, and ternary oxides with substituted metal cations, exhibit a broad range of complex conductivity transitions, as well as charge ordering transitions, structural phase transitions, frustrated spin structures, superconductivity, and unusual magnetic properties. As such, vanadates are a prototypical class of correlated material, where fundamentally important physical themes can be explored, both experimentally and theoretically. The experimental tools used were soft x-ray emission spectroscopy (XES), soft x-ray absorption spectroscopy (XAS), resonant inelastic soft x ray scattering (RIXS), x-ray photoemission spectroscopy (XPS), angle resolved photoemission spectroscopy (ARPES), and spectroscopic photoemission low energy electron microscopy (SPELEEM). This broad range of techniques delivered data that was used to understand the electronic structure in these oxides. Vanadium oxides as single crystals, thin films, polycrystalline powders, and nanoparticles were studied to determine the influence of the physical structure the materials properties. A rich and varied selection of experiments were performed, and by combining the information gathered by our x-ray spectroscopic techniques, we developed a comprehensive understanding of electronic structure in vanadium oxides. We measured band structures and Fermi surfaces, studied the coupling between collective excitations and quasi-particles, measured the local, site and element specific electronic structure, as well as the cation charge state, measured orbital hybridization, and measured element specific low energy valence excitations such as dd* and charge transfer excitations.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2025

IER 516: Zirconium Test Assembly CED Phase-1: Preliminary Experiment Design

IER-516, Zirconium Test Assembly (ZTA), is a campaign to design, execute, and document a series of high-fidelity critical benchmark experiments to validate current and future zirconium (Zr) and zirconium hydride (ZrH x ) nuclear data evaluations. ZTA is a collaborative project between Los Alamos National Laboratory and the French Autoritè de Sûretè Nuclèaire et de Radioprotection. The experiments will be fueled with highly enriched uranium (HEU), and utilize the Comet critical assembly machine at the National Criticality Experiments Research Center. A total of ten preliminary critical experiments were designed and optimized for Zr and ZrHx nuclear data sensitivities using the MCNP-Particle Swarm Optimization methodology in the thermal, epithermal, intermediate, and fast neutron energy regions.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗