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DOE OSTI2020

Materials Data on Pb(SN)2 by Materials Project

Pb(NS)2 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is zero-dimensional and consists of four lead molecules and four NS clusters. In each NS cluster, there are two inequivalent N1+ sites. In the first N1+ site, N1+ is bonded in a single-bond geometry to one S2- atom. The N–S bond length is 1.55 Å. In the second N1+ site, N1+ is bonded in a bent 120 degrees geometry to two S2- atoms. There is one shorter (1.57 Å) and one longer (1.68 Å) N–S bond length. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a bent 120 degrees geometry to two N1+ atoms. In the second S2- site, S2- is bonded in a distorted single-bond geometry to one N1+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Pb(NCl3)2 by Materials Project

N2PbCl6 is Fluorite structured and crystallizes in the cubic Fm-3m space group. The structure is zero-dimensional and consists of eight ammonia molecules and four PbCl6 clusters. In each PbCl6 cluster, Pb4+ is bonded in an octahedral geometry to six equivalent Cl1- atoms. All Pb–Cl bond lengths are 2.57 Å. Cl1- is bonded in a single-bond geometry to one Pb4+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Pb(CO)4 by Materials Project

(C)2PbC2O4 crystallizes in the tetragonal I4_1/amd space group. The structure is three-dimensional and consists of four ethyne molecules and one PbC2O4 framework. In the PbC2O4 framework, Pb2+ is bonded to eight equivalent O2- atoms to form distorted edge-sharing PbO8 hexagonal bipyramids. There are four shorter (2.62 Å) and four longer (2.74 Å) Pb–O bond lengths. C+1.50+ is bonded in a bent 120 degrees geometry to two equivalent O2- atoms. Both C–O bond lengths are 1.27 Å. O2- is bonded in a distorted single-bond geometry to two equivalent Pb2+ and one C+1.50+ atom.

36 MATERIALS SCIENCE↗

DOE OSTI2020

U-Pb zircon age constraints on the earliest eruptions of the Deccan Large Igneous Province, Malwa Plateau, India

Climate instability driven by emission of volatiles during emplacement of large igneous provinces (LIPs) is frequently invoked as a potential cause of mass extinctions. However, documenting this process in the geologic record requires a holistic understanding of eruption rates, the location of eruptive centers, and potential sources of climate-changing volatiles. We present new chemical abrasion–isotope dilution–thermal ionization mass spectrometry (CA-ID-TIMS) U-Pb zircon geochronology from Malwa Plateau basalts on the northern margin of the Deccan LIP, India. These basalts have been previously interpreted as either an extension of the province's main volcanic stratigraphy or as an independent eruptive center active up to millions of years prior to the main eruptive phase. Our data instead demonstrate that the lower Malwa Plateau basalts are temporally correlative with the first pulse of Deccan volcanism and provide new constraints on its initiation and duration. Paleomagnetic data further indicate that upper Malwa Plateau basalts may be age-equivalent to the second, third, and fourth pulses of Deccan volcanism. The relative thicknesses of age-equivalent packages of basalt are consistent with eruption of the Deccan LIP from a southward-migrating eruptive center. The first eruptive pulse is coeval with a ~200 kyr Late Maastrichtian warming event preserved globally in contemporaneous stratigraphic sections. We propose that the first pulse of Deccan magmatism was more voluminous in the north, where it erupted through organic-rich sedimentary rocks of the Narmada-Tapti rift basin. Thermal metamorphism of these sediments could have been a source of sufficient CO 2 to drive the Late Maastrichtian warming event, which if true would reconcile the apparent dampened warming signals associated with later Deccan eruptive pulses.

58 GEOSCIENCES↗

DOE OSTI2022

Strain‐Driven Mixed‐Phase Domain Architectures and Topological Transitions in Pb 1− x Sr x TiO 3 Thin Films

Abstract The potential for creating hierarchical domain structures, or mixtures of energetically degenerate phases with distinct patterns that can be modified continually, in ferroelectric thin films offers a pathway to control their mesoscale structure beyond lattice‐mismatch strain with a substrate. Here, it is demonstrated that varying the strontium content provides deterministic strain‐driven control of hierarchical domain structures in Pb 1− x Sr x TiO 3 solid‐solution thin films wherein two types, c / a and a 1 / a 2 , of nanodomains can coexist. Combining phase‐field simulations, epitaxial thin‐film growth, detailed structural, domain, and physical‐property characterization, it is observed that the system undergoes a gradual transformation (with increasing strontium content) from droplet‐like a 1 / a 2 domains in a c / a domain matrix, to a connected‐labyrinth geometry of c / a domains, to a disconnected labyrinth structure of the same, and, finally, to droplet‐like c / a domains in an a 1 / a 2 domain matrix. A relationship between the different mixed‐phase modulation patterns and its topological nature is established. Annealing the connected‐labyrinth structure leads to domain coarsening forming distinctive regions of parallel c / a and a 1 / a 2 domain stripes, offering additional design flexibility. Finally, it is found that the connected‐labyrinth domain patterns exhibit the highest dielectric permittivity.

Kavle, Pravin↗

DOE OSTI2024

Architecture and performance of Perlmutter's 35 PB ClusterStor E1000 all-flash file system

NERSC's newest system, Perlmutter, features a 35 PB all-flash Lustre file system built on HPE Cray ClusterStor E1000. Here, we present its architecture, early performance figures, and performance considerations unique to this architecture. We demonstrate the performance of E1000 OSSes through low-level Lustre tests that achieve over 90% of the theoretical bandwidth of the SSDs at the OST and LNet levels. We also show end-to-end performance for both traditional dimensions of I/O performance (peak bulk-synchronous bandwidth) and nonoptimal workloads endemic to production computing (small, incoherent I/Os at random offsets) and compare them to NERSC's previous system, Cori, to illustrate that Perlmutter achieves the performance of a burst buffer and the resilience of a scratch file system. Finally, we discuss performance considerations unique to all-flash Lustre and present ways in which users and HPC facilities can adjust their I/O patterns and operations to make optimal use of such architectures.

97 MATHEMATICS AND COMPUTING↗

DOE OSTI2022

The pH and Potential Dependence of Pb–Catalyzed Electrochemical CO 2 Reduction to Methyl Formate in a Dual Methanol/Water Electrolyte

The conversion of waste CO 2 to value-added chemicals through electrochemical reduction is a promising technology for mitigating climate change while simultaneously providing economic opportunities. The use of non-aqueous solvents like methanol allows for higher CO 2 availability and novel products. In this work, the electrochemistry of CO 2 reduction in acidic methanol catholyte at a Pb working electrode was investigated while using a separate aqueous anolyte to promote a sustainable water oxidation half-reaction. The selectivity among methyl formate (a product unique to reduction of CO 2 in methanol), formic acid, and formate was critically dependent on the catholyte pH, with higher pH conditions leading to formate and low pH favoring methyl formate. Furthermore, the potential dependence of the product distribution in acidic catholyte was also investigated, with a faradaic efficiency for methyl formate as high as 75% measured at -2.0 V vs Ag/AgCl.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

DOE OSTI2024

Multiplicity and event-scale dependent flow and jet fragmentation in pp collisions at $\sqrt{s}$ = 13 TeV and in p–Pb collisions at $\sqrt{s_{\textrm{NN}}}$ = 5.02 TeV

Long- and short-range correlations for pairs of charged particles are studied via two-particle angular correlations in pp collisions at $\sqrt{s}$ = 13 TeV and p–Pb collisions at $\sqrt{s_{\textrm{NN}}}$ = 5.02 TeV. The correlation functions are measured as a function of relative azimuthal angle Δφ and pseudorapidity separation Δη for pairs of primary charged particles within the pseudorapidity interval |η| < 0.9 and the transverse-momentum interval 1 < p T < 4 GeV/c. Flow coefficients are extracted for the long-range correlations (1.6 < |Δη| < 1.8) in various high-multiplicity event classes using the low-multiplicity template ft method. The method is used to subtract the enhanced yield of away-side jet fragments in high-multiplicity events. These results show decreasing flow signals toward lower multiplicity events. Furthermore, the flow coefficients for events with hard probes, such as jets or leading particles, do not exhibit any significant changes compared to those obtained from high-multiplicity events without any specific event selection criteria. The results are compared with hydrodynamic-model calculations, and it is found that a better understanding of the initial conditions is necessary to describe the results, particularly for low-multiplicity events.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2023

J/ψ production at midrapidity in p-Pb collisions at $ \sqrt{s_{\textrm{NN}}}$ = 8.16 TeV

The production of inclusive, prompt and non-prompt J/ψ was studied for the first time at midrapidity (–1.37 < y cms < 0.43) in p-Pb collisions at $\sqrt{s_{NN}}$ = 8.16 TeV with the ALICE detector at the LHC. The inclusive J/ψ mesons were reconstructed in the dielectron decay channel in the transverse momentum (p T ) interval 0 < p T < 14 GeV/c and the prompt and non-prompt contributions were separated on a statistical basis for p T > 2 GeV/c. The study of the J/ψ mesons in the dielectron channel used for the first time in ALICE online single-electron triggers from the Transition Radiation Detector, providing a data sample corresponding to an integrated luminosity of 689 ± 13 μb –1 . The proton-proton reference cross section for inclusive J/ψ was obtained based on interpolations of measured data at different centre-of-mass energies and a universal function describing the p T -differential J/ψ production cross sections. The p T -differential nuclear modification factors R pPb of inclusive, prompt, and non-prompt J/ψ are consistent with unity and described by theoretical models implementing only nuclear shadowing.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2020

J/ψ production as a function of charged-particle multiplicity in p-Pb collisions at $ \sqrt{s_{\mathrm{NN}}} $ = 8.16 TeV

Inclusive J /ψ yields and average transverse momenta in p-Pb collisions at a center-of-mass energy per nucleon pair $ \sqrt{s_{\mathrm{NN}}} $ = 8 . 16 TeV are measured as a function of the charged-particle pseudorapidity density with ALICE. The J /ψ mesons are reconstructed at forward (2 . 03 < y cms < 3 . 53) and backward ( - 4 . 46 < y cms < - 2 . 96) center-of-mass rapidity in their dimuon decay channel while the charged-particle pseudorapidity density is measured around midrapidity. The J /ψ yields at forward and backward rapidity normalized to their respective average values increase with the normalized charged-particle pseudorapidity density, the former showing a weaker increase than the latter. The normalized average transverse momenta at forward and backward rapidity manifest a steady increase from low to high charged-particle pseudorapidity density with a saturation beyond the average value.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2021

Jet fragmentation transverse momentum distributions in pp and p-Pb collisions at $ \sqrt{s}$, $\sqrt{s_{\mathrm{NN}}}$ = 5.02 TeV

Jet fragmentation transverse momentum ( j T ) distributions are measured in proton-proton (pp) and proton-lead (p-Pb) collisions at s NN = 5 . 02 TeV with the ALICE experiment at the LHC. Jets are reconstructed with the ALICE tracking detectors and electromagnetic calorimeter using the anti- k T algorithm with resolution parameter R = 0 . 4 in the pseudorapidity range |η| < 0 . 25. The j T values are calculated for charged particles inside a fixed cone with a radius R = 0 . 4 around the reconstructed jet axis. The measured j T distributions are compared with a variety of parton-shower models. Herwig and P ythia 8 based models describe the data well for the higher j T region, while they underestimate the lower j T region. The j T distributions are further characterised by fitting them with a function composed of an inverse gamma function for higher j T values (called the “wide component”), related to the perturbative component of the fragmentation process, and with a Gaussian for lower j T values (called the “narrow component”), predominantly connected to the hadronisation process. The width of the Gaussian has only a weak dependence on jet transverse momentum, while that of the inverse gamma function increases with increasing jet transverse momentum. For the narrow component, the measured trends are successfully described by all models except for Herwig. For the wide component, Herwig and PYTHIA 8 based models slightly underestimate the data for the higher jet transverse momentum region. These measurements set constraints on models of jet fragmentation and hadronisation.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2024

Observation of $t\overline{t}$ production in the lepton+jets and dilepton channels in p+Pb collisions at $\sqrt{s_{\textrm{NN}}}$ = 8.16 TeV with the ATLAS detector

This paper reports the observation of top-quark pair production in proton-lead collisions in the ATLAS experiment at the Large Hadron Collider. The measurement is performed using 165 nb -1 of p+Pb data collected at $\sqrt{^sNN}$ = 8.16 TeV in 2016. Events are categorised in two analysis channels, consisting of either events with exactly one lepton (electron or muon) and at least four jets, or events with two opposite-charge leptons and at least two jets. In both channels at least one b-tagged jet is also required. Top-quark pair production is observed with a significance over five standard deviations in each channel. The top-quark pair production cross-section is measured to be σ $t\overline{t}$ =58.1 ± 2.0(stat.)$^{+4.8}_{-4.4}$(syst.) nb, with a total uncertainty of 9%. In addition, the nuclear modification factor is measured to be R pA = 1.090 ± 0.039(stat.)$^{+0.094}_{-0.087}$(syst.). The measurements are found to be in good agreement with theory predictions involving nuclear parton distribution functions.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

DOE OSTI2023

Behavior of selenium and arsenic in $\mathrm{HCl}$ and $\mathrm{HNO}$ 3 on $\mathrm{TRU, TEVA, DGA,}$ and $\mathrm{Pb}$ extraction chromatography resins

The uptake behavior of 73 As and 75 Se was studied in HCl and HNO 3 -H 2 O 2 solutions on commercial extraction chromatography resins (TEVA, TRU, DGA, and Pb resin). There was no uptake of 73 As or 75 Se from HNO 3 media. From HCl, there was 75 Se uptake at high concentrations on all the resins and no uptake of 73 As. Separations of 75 Se and 73 As on these resins have high yields and high radiopurity for 73 As, but limited recovery of 75 Se. TRU and TEVA resin may have potential for use in isotope generators as 75 Se can be retained for at least 26 days with repeated elutions.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

DOE OSTI2023

Synergistic extraction of rare earth elements, actinium, americium, and barium with TTA and Pb resin from acetate buffer solutions

The uptake behavior of 88 Y, 140 Ba, 140 La, 141 Ce, 152 Eu, 228 Ac, and 241 Am was studied with batch uptake, kinetics and column studies in a synergistic extraction system with Pb resin and 2-thenoyltrifuoroacetone in acetate-ethanol solutions. The k' values are very high (>10,000) at near neutral pH (~5 to 6) for all of the radioisotopes studied. The kinetics are reasonably fast for column separations, though the uptake rate is dependent on the concentration of 2-thenoyltrifuoroacetone. Column studies were performed to demonstrate the separation of the trivalent actinides and lanthanides from barium and common fssion products ( 99 Mo, 103 Ru).

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

DOE OSTI2024

Uptake of arsenic and selenium on iron-doped Pb resin

We report the uptake of the radioisotopes 73 As and 75 Se was characterized on Fe 3+ -doped Pb resin (Eichrom Technologies) from pH 1 to 12. There is good uptake of arsenic and selenium over a wide pH range (~ 1 to 10) with a decrease only at high pH (~ 12). Column experiments were performed to demonstrate the separations of these elements from solutions with near neutral pH values (~ 6 to 8) with high yields and high radiopurity. These separations may be relevant for a wide variety of applications especially isotope harvesting research.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗

DOE OSTI2020

Structural origin of size effect on piezoelectric performance of Pb(Zr,Ti)O 3

Grain size effect plays a vital role in piezoelectric performance from both scientific and technological view. However, the underlying structural mechanism related to grain size is still unclear. In the present study, the structural mechanism of grain size effect on piezoelectric performance has been revealed in the prototype Pb(Zr, Ti)O 3 system by using in-situ synchrotron X-ray diffraction. The miniaturization of grain size tends to favor the appearance of higher symmetric tetragonal phase, while a single monoclinic phase is determined in the coarse-grained ceramics. The direct structural evidence reveals that both tetragonal and monoclinic phases in the fine-grained ceramics are less sensitive to the electric field, corresponding to the inferior piezoelectric performance, while the single monoclinic phase in the coarse-grained ceramics is more active to be driven by the electric field, generating good piezoelectric behavior. Both domain switching ability and lattice strain are suppressed with decreasing grain size, which directly leads to the deterioration in piezoelectric performance. In conclusion, the current results will benefit the structural understanding of the size effect of piezoelectric and other related systems.

36 MATERIALS SCIENCE↗

DOE OSTI2021

Detrital U-Pb zircon and 40 Ar/ 39 Ar muscovite geochronology from Middle Pennsylvanian strata in the Anadarko Basin, Texas Panhandle, USA

The Late Mississippian-Permian Anadarko Basin formed in Texas and Oklahoma, USA as the result of inversion of Neoproterozic and Cambrian rift structures. Subsidence was driven by flexural loading of the Amarillo-Wichita Uplift, and this uplift may represent the easternmost element of the Ancestral Rocky Mountains system. The northwestern part of this basin has generally been interpreted to have been filled by sediment derived from the Ancestral Front Range Uplift, ~475 km to the northwest during the early stages of basin filling. We test this model using U-Pb detrital zircon and 40 Ar/ 39 Ar detrital muscovite results from three subsurface samples of the Morrow B sandstone in the northwestern part of the Anadarko Basin. We provide a new maximum depositional age of 310.9 ± 4.9 Ma that indicates the age of the Morrow B to be no older than late Atokan to early Desmoinesian Age (Moscovian), ~10 Myr younger than previously interpreted. In contrast to some previous interpretations, we propose that the most likely source for the sediment in the Morrow B is the Amarillo Uplift to the south. Detrital zircon and detrital muscovite data have age peaks at 900–1300 Ma, 1370 Ma and 1600–1800 Ma corresponding to derivation from Grenville, Granite-Rhyolite and Yavapai-Mazatzal basement provinces, respectively. A dominant detrital zircon peak at 1370 Ma suggests that Mesoproterozoic granites in the Amarillo Uplift were exposed by Middle Pennsylvanian time, and detritus eroded from the Amarillo Uplift dominated the lowstand sediment budget of the Texas Panhandle during this time; small volumes of sediment were likely sourced from the Ancestral Front Range. In conclusion, this study presents the first detrital geochronology data from the subsurface Anadarko Basin and the first detrital muscovite data from late Paleozoic southwestern Laurentia. The results presented here highlight the interpretive power of combined detrital zircon and muscovite datasets.

58 GEOSCIENCES↗

DOE OSTI2022

Nuclear modification factor of light neutral-meson spectra up to high transverse momentum in p–Pb collisions at s NN = 8.16 TeV

Neutral pion (π 0 ) and η meson production cross sections were measured up to unprecedentedly high transverse momenta (p T ) in p–Pb collisions at √ s NN = 8.16 TeV. The mesons were reconstructed via their two-photon decay channel in the rapidity interval –1.3 < y < 0.3 in the ranges of 0.4 < p T < 200 GeV/c and 1.0 < p T < 50 GeV/c, respectively. The respective nuclear modification factor (R pPb ) is presented for p T up to of 200 and 30 GeV/c, where the former was achieved by extending the π 0 measurement in pp collisions at √s = 8 TeV using the merged cluster technique. The values of R pPb are below unity for p T < 10 GeV/c, while they are consistent with unity for p T > 10 GeV/c, leaving essentially no room for final state energy loss. The new data provide strong constraints for nuclear parton distribution and fragmentation functions over a broad kinematic range and are compared to model predictions as well as previous results at √ s NN = 5.02 TeV.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗