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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 73 records · Page 4

Spallation neutron source GNEIS

A brief description of the spallation pulsed neutron source and neutron TOF spectrometer GNEIS based on the 1 GeV proton synchrocyclotron of PNPI in Gatchina is presented. The main parameters of the GNEIS are given in comparison with the analogous world-class facilities. The experimental capabilities of the GNEIS are demonstrated by the examples of some nuclear physics and applied research experiments carried out during four decades of its operation.

43 PARTICLE ACCELERATORS↗

Imaging analysis of LDEF craters

Two small craters in Al from the Long Duration Exposure Facility (LDEF) experiment tray A11E00F (no. 74, 119 micron diameter and no. 31, 158 micron diameter) were analyzed using Auger electron spectroscopy (AES), time-of-flight secondary ion mass spectroscopy (TOF-SIMS), low voltage scanning electron microscopy (LVSEM), and SEM energy dispersive spectroscopy (EDS). High resolution images and sensitive elemental and molecular analysis were obtained with this combined approach. The result of these analyses are presented.

Radicatidibrozolo, F.↗

First measurement in a magnetic confinement fusion experiment of the H 3 + H 3 → He 5 + n intermediate two-body resonant reaction

We report on the first experimental measurements made at a magnetic confinement fusion device of the tritium(T)-tritium(T) reaction T + T → He 4 + 2 n indicating the presence of the intermediate two-body resonant reaction T + T → He 5 + n . During the second deuterium-tritium campaign (DTE2) at the Joint European Torus, measurements of fusion plasmas with high tritium concentrations, n T / ( n T + n D ) ≈ 0.99 , heated with tritium neutral beam injection, were performed using the neutron time-of-flight (TOF) spectrometer TOFOR. We detect a peak in the neutron emission TOF spectrum consistent with the two-body resonant reaction. The TT neutron emission energy spectrum is modeled using an R -matrix framework where the distributions of the most likely model parameters given our experimental TOF data are determined utilizing a Markov chain Monte Carlo approach. We compare our best estimate of the T + T neutron emission energy spectrum with results obtained at inertial confinement fusion experiments at the OMEGA facility and find a spectral shape that is consistent with the energy dependency in the neutron spectrum observed at OMEGA. Published by the American Physical Society 2024

Physics↗

EPCAPE – Proton Transfer Reaction Mass Spectrometer Field Campaign Report

The Eastern Pacific Cloud Aerosol Precipitation Experiment – Proton Transfer Reaction Mass Spectrometer (EPCAPE-PTRMS) campaign was created in response to the urgent need expressed by EPCAPE co-investigators for measurements of volatile organic compounds (VOCs) during the EPCAPE intensive operational period. A proton transfer reaction time-of-flight mass spectrometer (PTR-ToF-MS, model 8000, Ionicon Analytik) was deployed to Mt. Soledad, San Diego, California, on 15 May 2023 for the measurement of VOCs. The instrument was installed in the same Atmospheric Radiation Measurement (ARM) user facility guest container that the Smith group used for the EPCAPE – Ultrafine Particle Properties (EPCAPE-UPP) campaign. The Smith group provided the sample inlet and operated and maintained the instrument. A complete VOC mass spectrum was recorded every 10 sec, continuously. Calibrations using a traceable VOC mixture were performed onsite at the end of the campaign.

54 ENVIRONMENTAL SCIENCES↗

Rapid 235 U/ 238 U determination by matrix assisted ionization–time-of-flight mass spectrometry

Matrix-assisted ionization (MAI) of inorganic analytes is a nascent research domain that holds promise for rapid, potentially facility-deployable analytical applications. Here, we present results of MAI uranium isotopic analysis ( 235 U/ 238 U) obtained on the timescale of minutes utilizing simple sample preparation and an ambient ionization time-of-flight mass spectrometer (ToF MS). Experimental MAI-ToF MS characterization of uranium Certified Reference Materials (CRMs) was used to establish method calibration and validate quantitative 235 U/ 238 U determination spanning depleted, natural, and low-enriched uranium isotopic compositions. Secondary standard analyses with total uranium mass loadings of 5–500 ng per analysis yield accurate calibrated 235 U/ 238 U results and relative uncertainties of 4.7–17.2% (approx. ±95% confidence level), with weighted-mean uncertainties approaching 1.5%. This method permits accurate determination of uranium isotopic composition in a sample with uranium content as low as 200 pg for equal atom 235 U: 238 U. Instrument detection limits constrain the minimum uranium mass required to identify the presence of highly enriched uranium (HEU ≥20% 235 U) as only 500 pg using the method presented here. MAI-ToF MS quantitation of relatively extreme isotope ratios ( 235 U/ 238 U ≤ 0.01) is limited by detection of minor 235 U (LoD 100 pg 235 U/analysis ≈ 10 ng total U/analysis), and subsequent method optimization is anticipated to further reduce these limits. These findings underscore the potential of MAI-ToF MS for isotopic characterization of uranium and other inorganic species for both basic and applied science.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗

Final Scientific EFNUDAT Workshop

Part 7 of The Final Scientific EFNUDAT Workshop - organized by the CERN/EN-STI group on behalf of n_TOF Collaboration - will be held at CERN, Geneva (Switzerland) from 30 August to 2 September 2010 inclusive.EFNUDAT website: http://www.efnudat.euTopics of interest include: Data evaluation; Cross section measurements; Experimental techniques; Uncertainties and covariances; Fission properties; Current and future facilities;International Advisory Committee: C. Barreau (CENBG, France) T. Belgya (IKI KFKI, Hungary) E. Gonzalez (CIEMAT, Spain) F. Gunsing (CEA, France) F.-J. Hambsch (IRMM, Belgium) A. Junghans (FZD, Germany) R. Nolte (PTB, Germany) S. Pomp (TSL UU, Sweden) Workshop Organizing Committee: Enrico Chiaveri (Chairman) Marco Calviani Samuel Andriamonje Eric Berthoumieux Carlos Guerrero Roberto Losito Vasilis Vlachoudis Workshop Assistant: Geraldine Jean.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Tandem Nitrogen Functionalization of Porous Carbon: Toward Immobilizing Highly Active Palladium Nanoclusters for Dehydrogenation of Formic Acid

Highly dispersed palladium nanoclusters (Pd NCs) immobilized by a nitrogen (N)-functionalized porous carbon support (N-MSC-30) are synthesized by a wet chemical reduction method, wherein the N-MSC-30 prepared by a tandem low temperature heat-treatment approach proved to be a distinct support for stabilizing the Pd NCs. The prepared Pd/N-MSC-30 shows extremely high catalytic activity and recyclability for the dehydrogenation of formic acid (FA), affording the highest turnover frequency (TOF = 8414 h -1 ) at 333 K, which is much higher than that of the Pd catalyst supported on the N-MSC-30 prepared via a one-step process. This tandem heat treatment strategy provides a facile and effective synthetic methodology to immobilize ultrafine metal NPs on N-functionalized carbon materials, which have tremendous application prospects in various catalytic fields.

dehydrogenation↗

Final Scientific EFNUDAT Workshop

The Final Scientific EFNUDAT Workshop - organized by the CERN/EN-STI group on behalf of n_TOF Collaboration - will be held at CERN, Geneva (Switzerland) from 30 August to 2 September 2010 inclusive. EFNUDAT website: http://www.efnudat.euTopics of interest include: Data evaluation; Cross section measurements; Experimental techniques; Uncertainties and covariances; Fission properties; Current and future facilities. International Advisory Committee: C. Barreau (CENBG, France) T. Belgya (IKI KFKI, Hungary) E. Gonzalez (CIEMAT, Spain) F. Gunsing (CEA, France) F.-J. Hambsch (IRMM, Belgium) A. Junghans (FZD, Germany) R. Nolte (PTB, Germany)S. Pomp (TSL UU, Sweden) Workshop Organizing Committee: Enrico Chiaveri (Chairman) Marco Calviani Samuel Andriamonje Eric Berthoumieux Carlos Guerrero Roberto Losito Vasilis Vlachoudis. Workshop Assistant: Geraldine Jean

99 GENERAL AND MISCELLANEOUS↗

Final Scientific EFNUDAT Workshop

Part 5 of The Final Scientific EFNUDAT Workshop - organized by the CERN/EN-STI group on behalf of n_TOF Collaboration - will be held at CERN, Geneva (Switzerland) from 30 August to 2 September 2010 inclusive. EFNUDAT website: http://www.efnudat.euTopics of interest include: Data evaluation Cross section measurements Experimental techniques Uncertainties and covariances Fission properties Current and future facilities International Advisory Committee: C. Barreau (CENBG, France) T. Belgya (IKI KFKI, Hungary)E. Gonzalez (CIEMAT, Spain) F. Gunsing (CEA, France)F.-J. Hambsch (IRMM, Belgium) A. Junghans (FZD, Germany) R. Nolte (PTB, Germany) S. Pomp (TSL UU, Sweden) Workshop Organizing Committee: Enrico Chiaveri (Chairman)Marco Calviani Samuel Andriamonje Eric Berthoumieux Carlos Guerrero Roberto Losito Vasilis Vlachoudis Workshop Assistant: Geraldine Jean

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

Final Scientific EFNUDAT Workshop

F. Kappeler speaks about EFNUDAT synergies in astrophysics in this second session of the Final Scientific EFNUDAT Workshop. The workshop was organized by the CERN/EN-STI group on behalf of n_TOF Collaboration - will be held at CERN, Geneva (Switzerland) from 30 August to 2 September 2010 inclusive. EFNUDAT website: http://www.efnudat.euTopics of interest include: Data evaluation Cross section measurements Experimental techniques Uncertainties and covariances Fission properties Current and future facilities; International Advisory Committee: C. Barreau (CENBG, France) T. Belgya (IKI KFKI, Hungary) E. Gonzalez (CIEMAT, Spain)F. Gunsing (CEA, France)F.-J. Hambsch (IRMM, Belgium)A. Junghans (FZD, Germany) R. Nolte (PTB, Germany)S. Pomp (TSL UU, Sweden);Workshop Organizing Committee: Enrico Chiaveri (Chairman) Marco Calviani Samuel Andriamonje Eric Berthoumieux Carlos Guerrero Roberto Losito Vasilis Vlachoudis Workshop Assistant: Geraldine Jean.

22NI↗

Final Scientific EFNUDAT Workshop

The Final Scientific EFNUDAT Workshop - organized by the CERN/EN-STI group on behalf of n_TOF Collaboration - will be held at CERN, Geneva (Switzerland) from 30 August to 2 September 2010 inclusive. EFNUDAT website: http://www.efnudat.euTopics of interest include: Data evaluation Cross section measurements Experimental techniques Uncertainties and covariances Fission properties Current and future facilities ; International Advisory Committee: C. Barreau (CENBG, France)T. Belgya (IKI KFKI, Hungary)E. Gonzalez (CIEMAT, Spain)F. Gunsing (CEA, France)F.-J. Hambsch (IRMM, Belgium)A. Junghans (FZD, Germany)R. Nolte (PTB, Germany)S. Pomp (TSL UU, Sweden) ;Workshop Organizing Committee: Enrico Chiaveri (Chairman)Marco Calviani Samuel Andriamonje Eric Berthoumieux Carlos Guerrero Roberto Losito Vasilis Vlachoudis;Workshop Assistant: Geraldine Jean

NEUTRONS↗

Final Scientific EFNUDAT Workshop

The Final Scientific EFNUDAT Workshop - organized by the CERN/EN-STI group on behalf of n_TOF Collaboration - will be held at CERN, Geneva (Switzerland) from 30 August to 2 September 2010 inclusive. EFNUDAT website: http://www.efnudat.eu. Topics of interest include: Data evaluation; Cross section measurements; Experimental techniques; Uncertainties and covariances; Fission properties; Current and future facilities. International Advisory Committee: C. Barreau (CENBG, France)T. Belgya (IKI KFKI, Hungary)E. Gonzalez (CIEMAT, Spain)F. Gunsing (CEA, France)F.-J. Hambsch (IRMM, Belgium)A. Junghans (FZD, Germany)R. Nolte (PTB, Germany)S. Pomp (TSL UU, Sweden). Workshop Organizing Committee: Enrico Chiaveri (Chairman); Marco Calviani; Samuel Andriamonje; Eric Berthoumieux; Carlos Guerrero; Roberto Losito; Vasilis Vlachoudis; Workshop Assistant: Geraldine Jean

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

Final Scientific EFNUDAT Workshop

The Final Scientific EFNUDAT Workshop - organized by the CERN/EN-STI group on behalf of n_TOF Collaboration - will be held at CERN, Geneva (Switzerland) from 30 August to 2 September 2010 inclusive. EFNUDAT website: http://www.efnudat.eu Topics of interest include: Data evaluation Cross section measurements, Experimental techniques, Uncertainties and covariances, Fission properties, Current and future facilities International, Advisory Committee: C. Barreau (CENBG, France)T. Belgya (IKI KFKI, Hungary) E. Gonzalez (CIEMAT, Spain) F. Gunsing (CEA, France) F.-J. Hambsch (IRMM, Belgium)A. Junghans (FZD, Germany) R. Nolte (PTB, Germany) S. Pomp (TSL UU, Sweden) Workshop Organizing Committee: Enrico Chiaveri (Chairman) Marco Calviani Samuel Andriamonje Eric Berthoumieux Carlos Guerrero Roberto Losito Vasilis Vlachoudis Workshop Assistant: Geraldine Jean

ESS↗

Final Scientific EFNUDAT Workshop

The Final Scientific EFNUDAT Workshop - organized by the CERN/EN-STI group on behalf of n_TOF Collaboration - will be held at CERN, Geneva (Switzerland) from 30 August to 2 September 2010 inclusive. EFNUDAT website: http://www.efnudat.eu. Topics of interest include: Data evaluation, Cross section measurements, Experimental techniques, Uncertainties and covariances, Fission properties, and Current and future facilities. International Advisory Committee: C. Barreau (CENBG, France), T. Belgya (IKI KFKI, Hungary), E. Gonzalez (CIEMAT, Spain), F. Gunsing (CEA, France), F.-J. Hambsch (IRMM, Belgium), A. Junghans (FZD, Germany), R. Nolte (PTB, Germany)S. Pomp (TSL UU, Sweden) Workshop Organizing Committee: Enrico Chiaveri (Chairman), Marco Calviani, Samuel Andriamonje, Eric Berthoumieux, Carlos Guerrero, Roberto Losito, Vasilis Vlachoudis. Workshop Assistant: Geraldine Jean

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗

In situ liquid SIMS analysis of uranium oxide

Trace analysis of nuclear materials in solid particles collected in the environment or particles in liquid slurry generated in nuclear material manufacturing processes can pinpoint elemental, organic, and isotopic signatures of nuclear fuel cycle activities and processes. Such information can support nuclear safeguards programs by increasing our ability to detect undeclared nuclear materials, routine activities for safeguarding at declared facilities, and illicit activities. However, trace radioactive material analysis in liquids and slurries is challenging using bulk approaches. For example, one drawback of sensitive analysis such as inductively coupled plasma mass spectrometry (ICP-MS) is that sample is consumed or destroyed as a result of the technical approach. We developed a vacuum compatible microfluidic interface to enable surface analysis of liquids and liquid-solid interactions using time-of-flight secondary ion mass spectrometry (ToF-SIMS). In this work, we illustrate initial results of liquid standards containing uranium using in situ liquid SIMS. Specifically a series of diluted uranium standards used for ICPMS analysis were studied and the limit of detection was estimated. Since the liquid SIMS analysis is almost nondestructive, the same sample can be analyzed by other more destructive approaches afterwards or saved for future references. Consequently, multimodal analysis is possible. Our results demonstrate that in situ liquid SIMS can be used as a new approach to analyze radioactive materials in liquid and slurry forms of relevance to the IAEA safeguards missions.

In situ liquid ToF-SIMS, uranium, limit of detecti↗

Mapping the frontiers of the nuclear mass surface

Nuclear masses play a central role in nuclear astrophysics, significantly impacting the origin of the elements and observables used to constrain ultradense matter. A variety of techniques are available to meet this need, varying in their emphasis on precision and reach from stability. Here I briefly summarize the status of and near-future for the time-of-flight magnetic-rigidity (TOF-Bρ) mass measurement technique, emphasizing the complementary and interconnectedness with higher-precision mass measurement methods. This includes of recent examples from TOF-Bρ mass measurements that map the evolution of nuclear structure across the nuclear landscape and significantly impact the results and interpretation of astrophysical model calculations. I also forecast expected expansion in the known nuclear mass surface from future measurement at the Facility for Rare Isotope Beams.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗

Ionizing photon interactions modulate the optical properties of crystals with femtosecond scale temporal resolution

In this work, we continue our study of a new method for the detection of ionizing radiation with the potential for a dramatic improvement in coincidence time resolution (CTR) for time-of-flight positron emission tomography (ToF-PET) using the modulation of a material's optical properties instead of the scintillation mechanism. Our previous work has shown that for non-scintillation materials such as bismuth silicon oxide (BSO) and cadmium telluride (CdTe), their refractive index can be modulated by annihilation photon interactions. Additionally, the ultrafast nature of this process however remains unexplored. The ionizing radiation-induced charge carriers alter the local band structure in these materials, thus changing the complex refractive index. This mechanism is routinely used at the linac coherent light source (LCLS) facility of the SLAC National Accelerator Laboratory to measure x-ray pulse arrival times with femtosecond scale resolution for photon energies between 0.5 and 10 keV. The method described here follows that example by using a frequency chirped visible continuum pulse to provide a monotonic wavelength-to-time mapping by which one can measure the time-dependent refractive index modulation. In addition, we describe an interference-based measurement setup that allows for significantly improved sensitivity while preserving a timing precision of approximately 10 fs (σ) when measuring the arrival time of below 10 keV x-ray pulses with yttrium aluminum garnet (YAG) crystal. The method is presented in the context of ToF-PET application with further discussions on the potential CTR achievable if a similar detection concept is adopted for detecting 511 keV photons. Semi-empirical analysis indicates that the predicted CTR achievable is on the order of 1 ps (FWHM).

59 BASIC BIOLOGICAL SCIENCES↗

Global polarization of hyperons and spin alignment of vector mesons in quark matters

Relativistic heavy ion collider (RHIC) as a dedicated nuclear facility has made a few major discoveries in physics. This year marks the 30th year STAR Collaboration formation and the 23th year of STAR detector operation and data collection at RHIC. In the last two decades, STAR has collected many datasets, exhibiting scientific versatility and flexibility of the RHIC facility. The total dataset in the first year is less than 1 million good events, and currently there are about 1 billion events per dataset. The Global Hyperon Polarization was proposed in 2004. This immediately prompted the STAR Collaboration to search for this phenomenon from the early datasets. The null results were presented at Quark Matter Conference in Shanghai in 2006 and subsequently published. Although there were peripheral and continuous efforts in the following decade, no positive result has been observed experimentally. This situation changed in the following decade with the upgrade of high data rate and time-of-flight (TOF) detector and the progress of the Beam Energy Scan Phase I (BES-I). The experimental discoveries of the global polarization of hyperons in 2017 and the spin alignment of vector mesons in 2023 at RHIC-STAR confirm the theory which was established nearly twenty years ago. The theory and these measurements open the way to studying the properties of the hot and dense nuclear matter created in high-energy heavy ion collisions from a new degree of freedom, spin. We briefly review these discoveries from the proposals of theory to the experimental measurements, and summarize the related measurements at the existing facilities and the theoretical explanations to the original proposal. The basic understanding and the original proposal are still valid and fundamental, that is, the angular momentum of system can transform into a spin effect observable in experiment. However, it appears that in each case a new model is needed to explain the new experimental observation. We need a more basic theory to help us unify all these spin related phenomena. Over the past five years, STAR has successfully installed 3 new detectors and we have begun to see the physical analysis results from datasets with those new functions. What makes the STAR detector viable after 20 years of operation is its continuous evolution through successful upgrades, with new scientific programs added year by year. The next big thing is to forward upgrade a tracking system (3 layers of silicon strips and 4 layers of sTGC chambers) and a calorimetry system (electromagnetic and hadronic calorimeters). In addition to studying the spin structure of protons by using the polarized proton beams at RHIC, the upgrades also provide a unique ability to investigate the origin of Λ Global Polarization as a function of rapidity and rapidity (de-)correlations in Au+Au collisions.

Physics↗