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1. 2-km resolution oversampled NH3 data

Author(s):
Wang, Rui; Guo, Xuehui; Pan, Da; Kelly, James; Bash, Jesse; Sun, Kang; Paulot, Fabien; Clarisse, Lieven; Van Damme, Martin; Whitburn, Simon; Coheur, Pierre-François; Clerbaux, Cathy; Zondlo, Mark
Abstract:
Monthly, high resolution (~2 km) ammonia (NH3) column maps from the Infrared Atmospheric Sounding Interferometer (IASI) were developed across the contiguous United States and adjacent areas. Ammonia hotspots (95th percentile of the column distribution) were highly localized with a characteristic length scale of 12 km and median area of 152 km2. Five seasonality classes were identified with k-means++ clustering. The Midwest and eastern United States had a broad, spring maximum of NH3 (67% of hotspots in this cluster). The western United States, in contrast, showed a narrower mid-summer peak (32% of hotspots). IASI spatiotemporal clustering was consistent with those from the Ammonia Monitoring Network. CMAQ and GFDL-AM3 modeled NH3 columns have some success replicating the seasonal patterns but did not capture the regional differences. The high spatial-resolution monthly NH3 maps serve as a constraint for model simulations and as a guide for the placement of future, ground-based network sites.
Type:
Dataset
Issue Date:
December 2020

3. 60 degree Inclined Pulsar

Abstract:
Current sheet and open field lines with footpoints near the edge of the polar cap. The magnetic axis is inclined relative to the rotation axis by 60 degrees. Red field lines originate on the north polar cap and green field lines in the right panel originate on the south polar cap. Purple and grey colors indicate positive and negative net local charge density in the current sheet, which is shown between 1.2-2 light cylinder radii.
Type:
moving image
Issue Date:
21 November 2013

4. 90 degree Inclined Pulsar

Abstract:
Current sheet and open field lines with footpoints near the edge of the polar cap. The magnetic axis is inclined relative to the rotation axis by 90 degrees. Red field lines originate on the north polar cap and green field lines in the right panel originate on the south polar cap. Purple and grey colors indicate positive and negative net local charge density in the current sheet, which is shown between 1.2-2 light cylinder radii.
Type:
moving image
Issue Date:
21 November 2013

5. A Reduced Resistive Wall Mode Kinetic Stability Model for Disruption Forecasting

Author(s):
Berkery, J.W.; Sabbagh, S.A.; Bell, R.E.; Gerhardt, S.P.; LeBlanc, B.P.
Abstract:
Kinetic modification of ideal stability theory from stabilizing resonances of mode-particle interaction has had success in explaining resistive wall mode (RWM) stability limits in tokamaks. With the goal of real-time stability forecasting, a reduced kinetic stability model has been implemented in the new Disruption Event Characterization and Forecasting (DECAF) code, which has been written to analyze disruptions in tokamaks. The reduced model incorporates parameterized models for ideal limits on beta, a ratio of plasma pressure to magnetic pressure, which are shown to be in good agreement with DCON code calculations. Increased beta between these ideal limits causes a shift in the unstable region of delta W_K space, where delta W_K is the change in potential energy due to kinetic effects that is solved for by the reduced model, such that it is possible for plasmas to be unstable at intermediate beta but stable at higher beta. Gaussian functions for delta W_K are defined as functions of E cross B frequency and collisionality, with parameters reflecting the experience of the National Spherical Torus Experiment (NSTX). The reduced model was tested on a database of discharges from NSTX and experimentally stable and unstable discharges were separated noticeably on a stability map in E cross B frequency, collisionality space. The reduced model only failed to predict an unstable RWM in 15.6% of cases with an experimentally unstable RWM and performed well on predicting stability for experimentally stable discharges as well.
Type:
Dataset
Issue Date:
May 2017

6. A Riccati Solution for the Ideal MHD Plasma Response with Applications to Real-time Stability Control

Author(s):
Glasser, A.; Kolemen, E.; Glasser, A.H.
Abstract:
To effectuate near real-time feedback control of ideal MHD instabilities in a tokamak geometry, a rapid solution for stability analysis is a prerequisite. Toward this end, we reformulate the δW stability method with a Hamilton-Jacobi theory, elucidating analytical and numerical features of the generic tokamak ideal MHD stability problem. The plasma response matrix is demonstrated to be the solution of an ideal MHD matrix Riccati differential equation (MRDE). Since Riccati equations are prevalent in the control theory literature, such a shift in perspective brings to bear a range of numerical methods that are well-suited to the robust, fast solution of control problems. We discuss the usefulness of Riccati techniques in solving the stiff ODEs often encountered in ideal MHD stability analyses-—for example, in tokamak edge and stellarator physics. We then demonstrate the applicability of such methods to an existing 2D ideal MHD stability code—DCON—enabling its parallel operation in near real-time. Output is shown to match with high accuracy, and with wall-clock time ≪ 1s. Such speed may help enable active feedback ideal MHD stability control, especially in tokamak plasmas whose ideal MHD equilibria evolve with inductive timescale τ > 1s-—as in ITER.
Type:
Dataset
Issue Date:
March 2018

7. A dual-mechanism antibiotic kills Gram-negative bacteria and avoids drug resistance

Author(s):
Martin, James K; Sheehan, Joseph P; Bratton, Benjamin P; Moore, Gabriel M; Mateus, André; Li, Sophia Hsin-Jung; Kim, Hahn; Rabinowitz, Joshua D; Typas, Athanasios; Savitski, Mikhail M; Wilson, Maxwell Z; Gitai, Zemer
Abstract:
The rise of antibiotic resistance and declining discovery of new antibiotics have created a global health crisis. Of particular concern, no new antibiotic classes have been approved for treating Gram-negative pathogens in decades. Here, we characterize a compound, SCH-79797, that kills both Gram-negative and Gram-positive bacteria through a unique dual-targeting mechanism of action (MoA) with undetectably-low resistance frequencies. To characterize its MoA, we combined quantitative imaging, proteomic, genetic, metabolomic, and cell-based assays. This pipeline demonstrates that SCH-79797 has two independent cellular targets, folate metabolism and bacterial membrane integrity, and outperforms combination treatments in killing MRSA persisters. Building on the molecular core of SCH-79797, we developed a derivative, Irresistin-16, with increased potency and showed its efficacy against Neisseria gonorrheae in a mouse vaginal infection model. This promising antibiotic lead suggests that combining multiple MoAs onto a single chemical scaffold may be an underappreciated approach to targeting challenging bacterial pathogens.
Type:
Dataset
Issue Date:
20 May 2020

11. A reduced-turbulence regime in the Large Helical Device upon injection of low-Z materials powders

Author(s):
Nespoli, Federico; Tanaka, Kenji; Masuzaki, Suguru; Ashikawa, Naoko; Shoji, Mamoru; Gilson, Erik; Lunsford, Robert; Oishi, Tetsutarou; Ida, Katsumi; Yoshinuma, Mikirou; Takemura, Yuki; Kinoshita, Toshiki; Motojima, Gen; Osakabe, Masaki; Kenmochi, Naoki; Kawamura, Gakushi; Suzuki, Chihiro; Nagy, Alex; Bortolon, Alessandro; Pablant, Novimir; Mollén, Albert; Tamura, Naoki; Gates, David; Morisaki, Tomohiro
Type:
Dataset
Issue Date:
2023

12. A scalable real-time framework for Thomson scattering analysis: Application to NSTX-U

Author(s):
F. M. Laggner, A. Diallo, B. P. LeBlanc, R. Rozenblat, G. Tchilinguirian, E.Kolemen, the NSTX-U team
Abstract:
A detailed description of a prototype setup for real-time (rt) Thomson scattering (TS) analysis is presented and implemented in the multi-point Thomson scattering (MPTS) diagnostic system at the National Spherical Torus Experiment Upgrade(NSTX-U). The data acquisition hardware was upgraded with rt capable electronics (rt-analog digital converters (ADCs) and a rt server) that allow for fast digitization of the laser pulse signal of eight radial MPTS channels. In addition, a new TS spectrum analysis software for a rapid calculation of electron temperature (Te) and electron density (ne) was developed. Testing of the rt hardware and data analysis soft-ware was successfully completed and benchmarked against the standard, post-shot evaluation. Timing tests were performed showing that the end-to-end processing time was reproducibly below 17 ms for the duration of at least 5 s, meeting a 60 Hz deadline by the laser pulse repetition rate over the length of a NSTX-U discharge. The presented rt framework is designed to be scalable in system size, i.e. incorporation of additional radial channels by solely adding additional rt capable hardware. Furthermore, it is scalable in its operation duration and was continuously run for up to 30 min, making it an attractive solution for machines with long discharge duration such as advanced, non-inductive tokamaks or stellarators.
Type:
Dataset
Issue Date:
March 2019

13. A software package for plasma facing component analysis and design: the Heat flux Engineering Analysis Toolkit (HEAT)

Author(s):
Looby, Tom; Reinke, Matthew; Wingen, Andreas; Menard, Jonathan; Gerhardt, Stefan; Gray, Travis; Donovan, David; Unterberg, Ezekial; Klabacha, Jonathan; Messineo, Mike
Abstract:
The engineering limits of plasma facing components (PFCs) constrain the allowable operational space of tokamaks. Poorly managed heat fluxes that push the PFCs beyond their limits not only degrade core plasma performance via elevated impurities, but can also result in PFC failure due to thermal stresses or melting. Simple axisymmetric assumptions fail to capture the complex interaction between 3D PFC geometry and 2D or 3D plasmas. This results in fusion systems that must either operate with increased risk or reduce PFC loads, potentially through lower core plasma performance, to maintain a nominal safety factor. High precision 3D heat flux predictions are necessary to accurately ascertain the state of a PFC given the evolution of the magnetic equilibrium. A new code, the Heat flux Engineering Analysis Toolkit (HEAT), has been developed to provide high precision 3D predictions and analysis for PFCs. HEAT couples many otherwise disparate computational tools together into a single open source python package. Magnetic equilibrium, engineering CAD, finite volume solvers, scrape off layer plasma physics, visualization, high performace computing, and more, are connected in a single web-based user interface. Linux users may use HEAT without any software prerequisites via an appImage. This manuscript introduces HEAT, discusses the software architecture, presents first HEAT results, and outlines physics modules in development.
Type:
Dataset
Issue Date:
March 2021

14. A thermodynamic phase transition in magnetic reconnection

Author(s):
Jara-Almonte, Jonathan; Hantao, Ji
Abstract:
Data supporting the manuscript "A thermodynamic phase transition in magnetic reconnection" published in Physical Review Letters.
Type:
Dataset
Issue Date:
7 July 2021

15. Accessing Real-Life Episodic Information from Minutes versus Hours Earlier Modulates Hippocampal and High-Order Cortical Dynamics

Author(s):
Chen, Janice; Honey, Christopher; Simony, Erez; Arcaro, Michael; Norman, Kenneth; Hasson, Uri
Abstract:
It is well known that formation of new episodic memories depends on hippocampus, but in real-life settings (e.g., conversation), hippocampal amnesics can utilize information from several minutes earlier. What neural systems outside hippocampus might support this minutes-long retention? In this study, subjects viewed an audiovisual movie continuously for 25 min; another group viewed the movie in 2 parts separated by a 1-day delay. Understanding Part 2 depended on retrieving information from Part 1, and thus hippocampus was required in the day-delay condition. But is hippocampus equally recruited to access the same information from minutes earlier? We show that accessing memories from a few minutes prior elicited less interaction between hippocampus and default mode network (DMN) cortical regions than accessing day-old memories of identical events, suggesting that recent information was available with less reliance on hippocampal retrieval. Moreover, the 2 groups evinced reliable but distinct DMN activity timecourses, reflecting differences in information carried in these regions when Part 1 was recent versus distant. The timecourses converged after 4 min, suggesting a time frame over which the continuous-viewing group may have relied less on hippocampal retrieval. We propose that cortical default mode regions can intrinsically retain real-life episodic information for several minutes.
Type:
Dataset
Issue Date:
3 August 2015

16. Achromonodin-1 NMR spectra

Author(s):
Link, A. James; Carson, Drew V.; So, Larry; Cheung-Lee, Wai Ling
Abstract:
This entry encompasses the raw NMR spectra used to determine the structure of the lasso peptide achromonodin-1. Within one file are included the five following spectra: COSY, TOCSY, NOESY (150 ms mixing time), NOESY (700 ms mixing time), and C,H HSQC. The file requires Mestrenova software to read. These spectra were used to develop the 3D structure models of achromonodin-1 that are deposited at the protein data bank (PDB) as entry 8SVB.
Type:
Dataset
Issue Date:
June 2023

17. Advances in boronization on NSTX-Upgrade

Author(s):
Skinner, C.H.; Bedoya, F.; Scotti, F.; Allain, J.P.; Blanchard, W.; Cai, D.; Jaworski, M.; Koel, B.E.
Abstract:
Boronization has been effective in reducing plasma impurities and enabling access to higher density, higher confinement plasmas in many magnetic fusion devices. The National Spherical Torus eXperiment, NSTX, has recently undergone a major upgrade to NSTX-U in order to develop the physics basis for a ST-based Fusion Nuclear Science Facility (FNSF) with capability for double the toroidal field, plasma current, and NBI heating power and increased pulse duration from 1–1.5 s to 5–8 s. A new deuterated tri-methyl boron conditioning system was implemented together with a novel surface analysis diagnostic. We report on the spatial distribution of the boron deposition versus discharge pressure, gas injection and electrode location. The oxygen concentration of the plasma facing surface was measured by in-vacuo XPS and increased both with plasma exposure and with exposure to trace residual gases. This increase correlated with the rise of oxygen emission from the plasma.
Type:
Dataset
Issue Date:
January 2017

18. Aligned Nonspinning Dipoles

Abstract:
Magnetic field lines and current sheets for an orbiting neutron star binary with the magnetic moments of both stars aligned with the rotation axis. The stars are not spinning, i.e., R_{LC,∗} = ∞. Fields are by and large confined to the half of the magnetosphere closer to their source star. This movie shows the corotating field pattern as the orbit progresses.
Type:
moving image
Issue Date:
21 November 2013

19. Aligned Rapidly Spinning Dipoles

Abstract:
Magnetic field lines and current sheets for an orbiting neutron star binary with the magnetic moments of both stars aligned with the rotation axis. The stars are spinning rapidly at ∼ ms periods, with R_{LC,∗}/R_∗ = 2.7. Stellar spin winds fields backwards toroidally, and they can propagate to the far side of the magnetosphere closer to the opposing star. This movie shows the corotating field pattern as the orbit progresses.
Type:
moving image
Issue Date:
21 November 2013

20. Alternative energy vehicle deployment coupled with decarbonizing electricity generation amplifies climate, air quality and health co-benefits in China

Author(s):
Peng, Liqun; Liu, Feiqi; Zhou, Mi; Li, Mingwei; Zhang, Qiang; Mauzerall, Denise L.
Abstract:
China is the world's largest carbon emitter and suffers from severe air pollution. About one million deaths in China were attributable to air pollution in 2017. Alternative energy vehicles (AEVs), e.g. electric, hydrogen fuel cell, and natural gas vehicles, can help achieve both carbon emission mitigation and air quality improvement. However, climate, air quality and health co-benefit of AEVs powered by deeply decarbonized electricity generation remain poorly quantified. Here, we conduct a quantitative integrated assessment of the air quality, health, carbon emission mitigation and economic benefits of AEV deployment as the electricity grid decarbonizes in China. We find population-weighted annual PM2.5 and summer O3 concentration can decrease as large as 5.7μgm−3 and 4.9ppb. Annual avoided premature mortalities and years of life lost resulting from improved ambient air pollution can be as large as ~329,000 persons and ~1,611,000 years. We thus show that maximizing climate, air quality and health benefits of AEV deployment in China requires rapid decarbonization of the power system.
Type:
Dataset
Issue Date:
17 June 2021