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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 1,297 records · Page 72
All sourcesNASA NTRSDOE OSTI
DOE OSTI2016

The use of advanced mass spectrometry to dissect the life-cycle of photosystem II

Photosystem II (PSII) is a photosynthetic membrane-protein complex that undergoes an intricate, tightly regulated cycle of assembly, damage, and repair. The available crystal structures of cyanobacterial PSII are an essential foundation for understanding PSII function, but nonetheless provide a snapshot only of the active complex. To study aspects of the entire PSII life-cycle, mass spectrometry (MS) has emerged as a powerful tool that can be used in conjunction with biochemical techniques. In this article, we present the MS-based approaches that are used to study PSII composition, dynamics, and structure, and review the information about the PSII life-cycle that has been gained by these methods. This information includes the composition of PSII subcomplexes, discovery of accessory PSII proteins, identification of post-translational modifications and quantification of their changes under various conditions, determination of the binding site of proteins not observed in PSII crystal structures, conformational changes that underlie PSII functions, and identification of water and oxygen channels within PSII. Lastly, we conclude with an outlook for the opportunity of future MS contributions to PSII research.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2026

Advancing Porous Carbons: Understanding the Importance of Surface Chemistry for the Energy–Environment Nexus

This review intends, in a critical way, the comprehensive view of the importance of porous carbons surface chemistry for their applications in an energy− environment nexus. Surface chemistry is presented as a combination of functional heteroatom-containing groups, dopants, and structural defects. First, we briefly address carbon surface chemical environment and the methods of its modification and characterization, indicating their practical limitations. Then, the effects of surface chemistry on separation, catalysis, energy storage, sensing and microwave absorption are introduced. Besides a critical analysis of published findings on these topics, we also include our views on the advancement in the processes which rely on porous carbons surface chemistry, and identify strategic areas and directions that should deserve further attention. We focus on new findings and important original contributions to the field. Since the community of carbon researchers grows following the strategic application of these materials, the role of functional groups, dopants and structural defects in various cutting-edge applications is emphasized, showing the progress in the field and the evolution of findings. A clear determination of the effects of carbon surface is often a challenge since carbons porosity and the locations of specific bonds/sites/ defects in the carbon texture provide nanoconfinement effects.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2019

Insights into Structural Evolution of Lithium Peroxides with Reduced Charge Overpotential in Li–O 2 System

Reducing charge-discharge overpotential is of great significance to enhance efficiency and cyclability of Li–O 2 batteries. Here we successfully achieve dramatically reduced charge overpotential (0.4 V) via a rational design of cathode architecture, which features highly uniform Pt and Pt 3 Co nanocrystals embedding within nitrogen-doped cobalt@graphene heterostructures. Because of the improvement on the catalytic efficiency for optimizing the electrical and dynamic properties, the cathode design enables promising electrochemical performance. More importantly, the results reveal different overpotential prompted by different structural evolution of bulk Li 2 O 2 , which depends on the Pt modification approach (surface-coating and bulk-doping). This dependence is found to be attributed to the influence of Pt nanocomponents and their dispersion on the formation and decomposition mechanism of Li 2 O 2 . Density functional theory calculations provide mechanistic insights into the promotional effect of Pt and Pt 3 Co on the reduction of the charge overpotential. Lastly, an inner relationship between overpotential and electrochemical kinetics is proposed.

25 ENERGY STORAGE↗
DOE OSTI2013

Identification of ultramodified proteins using top-down spectra

Post-translational modifications (PTMs) play an important role in various biological processes through changing protein structure and function. Some ultramodified proteins (like histones) have multiple PTMs forming PTM patterns that define the functionality of a protein. While bottom-up mass spectrometry (MS) has been successful in identifying individual PTMs within short peptides, it is unable to identify PTM patterns spread along entire proteins in a coordinated fashion. In contrast, top-down MS analyzes intact proteins and reveals PTM patterns along the entire proteins. However, while recent advances in instrumentation have made top-down MS accessible to many laboratories, most computational tools for top-down MS focus on proteins with few PTMs and are unable to identify complex PTM patterns. We propose a new algorithm, MS-Align-E, that identifies both expected and unexpected PTMs in ultramodified proteins. We demonstrate that MS-Align-E identifies many protein forms of histone H4 and benchmark it against the currently accepted software tools.

Environmental Molecular Sciences Laboratory↗
DOE OSTI2016

Percutaneous Management of Accidentally Retained Foreign Bodies During Image-Guided Non-vascular Procedures: Novel Technique Using a Large-Bore Biopsy System

ObjectiveTo describe a novel percutaneous image-guided technique using a large-bore biopsy system to retrieve foreign bodies (FBs) accidentally retained during non-vascular interventional procedures.Materials and MethodsBetween May 2013 and October 2015, five patients underwent percutaneous retrieval of five iatrogenic FBs, including a biopsy needle tip in the femoral head following osteoblastoma biopsy and radiofrequency ablation (RFA); a co-axial needle shaft within a giant desmoid tumour following cryoablation; and three post-vertebroplasty cement tails within paraspinal muscles. All FBs were retrieved immediately following original procedures under local or general anaesthesia, using combined computed tomography (CT) and fluoroscopic guidance. The basic technique involved positioning a 6G trocar sleeve around the FB long axis and co-axially advancing an 8G biopsy needle to retrieve the FB within the biopsy core. Retrospective chart review facilitated analysis of procedures, FBs, technical success, and complications.ResultsMean FB size was 23 mm (range 8–74 mm). Four FBs were located within 10 mm of non-vascular significant anatomic structures. The basic technique was successful in 3 cases; 2 cases required technical modifications including using a stiff guide-wire to facilitate retrieval in the case of the post-cryoablation FB; and using the central mandrin of the 6G trocar to push a cement tract back into an augmented vertebra when initial retrieval failed. Overall technical success (FB retrieval or removal to non-hazardous location) was 100 %, with no complications.ConclusionPercutaneous image-guided retrieval of iatrogenic FBs using a large-bore biopsy system is a feasible, safe, effective, and versatile technique, with potential advantages over existing methods.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2026

Disentangling interlayer confinement and pore surface adsorption in functionalized smectites for tunable ethylene gas capture

Smectite-based adsorbents are increasingly being studied as sustainable packaging materials for scavenging ethylene, a plant hormone that accelerates fruit ripening. However, the mechanisms governing their uptake and retention remain poorly understood. Here, to tackle this question we systematically investigate ethylene gas-solid interactions in pristine, acid-activated, and choline-functionalized montmorillonites using a complementary combination of structural, gravimetric, and spectroscopic techniques, including inelastic neutron scattering. We experimentally distinguish ethylene populations associated with interlayer confinement, mesopore, and external surface adsorption. We show that chemical functionalization distinctly controls adsorption pathways: acid activation enhances total uptake by generating mesoporous adsorption sites and promoting partial interlayer intercalation, yielding capacities comparable to those of leading smectite-based adsorbents, while choline functionalization promotes preferential confinement and stabilization of guest molecules within the interlayer galleries. Advanced spectroscopic analysis provides molecular-level insight into confinement environments and interaction strengths. We also establish clear structure-property relationships by correlating uptake values derived from independent techniques, linking chemical modification, accessible adsorption domains, and retention behavior. These findings provide general design principles for tuning gas-solid interactions in functionalized layered silicates and highlight their potential as adaptable platforms for sustainable ethylene gas capture and selective adsorption technologies.

Ethylene adsorption mechanism↗
DOE OSTI2018

Differential inhibition of mucin-type O-glycosylation (MTOG) induced by peracetyl N-thioglycolyl-d-galactosamine (Ac5GalNTGc) in myeloid cells

Highlights: • Each cell type expresses specific set of glycosyl transferases that result in unique pattern of mucin-type O-glycosylation. • MTOG of CD antigens is regulated depending on the specific cell type, developmental stage, and resting or activated state. • Metabolic incorporation of N-thioglycolyl-d-galactosamine results in cell-type dependent differential inhibition of MTOG. • Myeloid cells metabolize Ac{sub 5}GalNTGc with varying efficiency resulting in differential inhibition of MTOG on CD43. Investigations on the structure and functional roles of glycosylation – an intricate, complex, and dynamic post translational modification on proteins – in biological processes has been a challenging task. Glycan modifications vary depending on the specific cell type, its developmental stage, and resting or activated state. In the present study, we aim to understand the differences between the mucin-type O-glycosylation (MTOG) of two functionally divergent human cell lines, K562 (chronic myeloid leukemia) and U937 (histiocytic lymphoma), having myeloid origins. MTOG is initiated by the addition of N-acetyl-α-d-galactosamine (GalNAc) to Ser/Thr of glycoproteins. We exploited the metabolic glycan engineering (MGE) strategy using the peracetyl N-thioglycolyl-d-galactosamine (Ac{sub 5}GalNTGc), a synthetic GalNAc analogue, to engineer the glycoconjugates. Ac{sub 5}GalNTGc was metabolized and incorporated as N-thioglycolyl-d-galactosamine (GalNTGc) in cell surface glycoproteins in both the cell lines with varying degrees of efficiency. Notably, metabolic incorporation of GalNTGc resulted in differential inhibition of MTOG. It was observed that endogenous glycosylation machinery of K562 is relatively more stringent for selecting GalNTGc whereas U937 is flexible towards this selection. Additionally, we studied how the glycan modifications vary on a given CD antigen in these cell lines. Particularly, MTOG on CD43 was differentially inhibited in K562 and U937 as revealed by glycan-dependent and glycan-independent antibodies. It was observed that the effect of MGE on CD43 was similar to global effects on both cell lines. Consequences of MGE using GalNAc analogues depend on the expression and activity of various glycosyl transferases which determine global glycosylation on cell surface as well as on specific glycoproteins.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2020

Consequences of long-term water exposure for bulk crystal structure and surface composition/chemistry of nickel-rich layered oxide materials for Li-ion batteries

Water exposure of layered nickel-rich transition metal oxide electrodes, widely used in high-energy lithium-ion batteries, has detrimental effects on the electrochemical performance, which complicates electrode handling and prevents implementation of environmentally benign aqueous processing procedures. Elucidating the degradation mechanisms in play may help rationally mitigate/circumvent key challenges. Here, the bulk structural consequences of long-term (>2.5 years) deuterated water (D2O) exposure of intercalation materials with compositions Li x Ni 0.5 Co 0.2 Mn 0.3 O 2 (NCM523) and Li x Ni 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) are studied by neutron powder diffraction (NPD). Detailed inspection of the NPD data reveals gradual formation of a secondary crystalline phase in all exposed samples, not previously reported for this system. This unknown phase forms faster in liquid- compared to vapor-exposed compounds. Structural modelling of the NPD data shows a stable level of Li/Ni anti-site defects and does not indicate any significant changes in lattice parameters or hydrogen-lithium (D + /Li + ) exchange in the structure. Consequently, the secondary phase formation must take place via transformation rather than modification of the parent material. X-ray photoelectron spectroscopy data indicate formation of LiHCO 3 /Li 2 CO 3 at the surface and a Li-deficient oxide in the sub-surface region of the pristine compounds, and the presence of adsorbed water and transition metal hydroxides at the exposed sample surfaces.

25 ENERGY STORAGE↗
DOE OSTI2016

The many phases of CaC{sub 2}

Polymorphic CaC{sub 2} was prepared by reacting mixtures of CaH{sub 2} and graphite with molar ratios between 1:1.8 and 1:2.2 at temperatures between 700 and 1400 °C under dynamic vacuum. These conditions provided a well controlled, homogeneous, chemical environment and afforded products with high purity. The products, which were characterized by powder X-ray diffraction, solid state NMR and Raman spectroscopy, represented mixtures of the three known polymorphs, tetragonal CaC{sub 2}-I and monoclinic CaC{sub 2}-II and -III. Their proportion is dependent on the nominal C/CaH{sub 2} ratio of the reaction mixture and temperature. Reactions with excess carbon produced a mixture virtually free from CaC{sub 2}-I, whereas high temperatures (above 1100 °C) and C-deficiency favored the formation of CaC{sub 2}-I. From first principles calculations it is shown that CaC{sub 2}-I is dynamically unstable within the harmonic approximation. This indicates that existing CaC{sub 2}-I is structurally/dynamically disordered and may possibly even occur as slightly carbon-deficient phase CaC{sub 2-δ}. It is proposed that monoclinic II is the ground state of CaC{sub 2} and polymorph III is stable at temperatures above 200 °C. Tetragonal I represents a metastable, heterogeneous, phase of CaC{sub 2}. It is argued that a complete understanding of the occurrence of three room temperature modifications of CaC{sub 2} will require a detailed characterization of compositional and structural heterogeneities within the high temperature form CaC{sub 2}-IV, which is stable above 450 °C. The effect of high pressure on the stability of the monoclinic forms of CaC{sub 2} was studied in a diamond anvil cell using Raman spectroscopy. CaC{sub 2}-II and -III transform into tetragonal CaC{sub 2}-I at about 4 and 1GPa, respectively. - Graphical abstract: The famous tetragonal form of CaC{sub 2}, CaC{sub 2}-I, is dynamically unstable. Why does it exist? Display Omitted - Highlights: • Critical review of complex polymorphism of the commodity chemical CaC{sub 2}. • Tetragonal CaC{sub 2}-I is identified as dynamical instable and its existence attributed to disorder. • With pressure monoclinic CaC{sub 2}-II and –III transform into tetragonal CaC{sub 2}-I. • The high temperature form CaC{sub 2}-IV is assigned a key role for understanding the polymorphism of CaC{sub 2}.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Tunable Photoluminescent Core/Shell Cu(+)-Doped ZnSe/ZnS Quantum Dots Codoped with Al(3+), Ga(3+), or In(3+).

Semiconductor quantum dots (QDs) with stable, oxidation resistant, and tunable photoluminescence (PL) are highly desired for various applications including solid-state lighting and biological labeling. However, many current systems for visible light emission involve the use of toxic Cd. Here, we report the synthesis and characterization of a series of codoped core/shell ZnSe/ZnS QDs with tunable PL maxima spanning 430-570 nm (average full width at half-maximum of 80 nm) and broad emission extending to 700 nm, through the use of Cu(+) as the primary dopant and trivalent cations (Al(3+), Ga(3+), and In(3+)) as codopants. Furthermore, we developed a unique thiol-based bidentate ligand that significantly improved PL intensity, long-term stability, and resilience to postsynthetic processing. Through comprehensive experimental and computational studies based on steady-state and time-resolved spectroscopy, electron microscopy, and density functional theory (DFT), we show that the tunable PL of this system is the result of energy level modification to donor and/or acceptor recombination pathways. By incorporating these findings with local structure information obtained from extended X-ray absorption fine structure (EXAFS) studies, we generate a complete energetic model accounting for the photophysical processes in these unique QDs. With the understanding of optical, structural, and electronic properties we gain in this study, this successful codoping strategy may be applied to other QD or related systems to tune the optical properties of semiconductors while maintaining low toxicity.

Cooper, Jason K↗
DOE OSTI2013

Electronic Transport Properties of Chemically Modified Double-Walled Carbon Nanotubes

We present a study on the quantum transport properties of chemically functionalized metallic double-walled carbon nanotubes (DWNTs) with lengths reaching the micrometer scale. First-principles calculations evidence that, for coaxial tubes separated by the typical graphitic van der Waals bond distance, the chemical modification of the outer wall with sp3-type defects affects the electronic structure of both the outer and the inner tube, which reduces significantly the charge transport capability of the DWNTs. For larger spacing between sidewalls, the conductivity of the outer wall decreases with increasing functional group coverage density, while charge transport in the inner tube is equivalent to that of a pristine nanotube. Additionally, [2 + 1] cycloaddition of CCl2 onto the outer DWNT sidewall barely affects the hyperconjugated π-network of the double wall, and charge transport remains in the quasi-ballistic regime. These results indicate an efficient route for tailoring electronic transport in DWNTs provided inner shell geometry and grafted functional groups are properly chosen.

Chemistry↗
DOE OSTI2013

Identification of Ultramodified Proteins Using Top-Down Mass Spectra

Post-translational modifications (PTMs) play an important role in various biological processes through changing protein structure and function. Some ultramodified proteins (like histones) have multiple PTMs forming PTM patterns that define the functionality of a protein. While bottom-up mass spectrometry (MS) has been successful in identifying individual PTMs within short peptides, it is unable to identify PTM patterns spread along entire proteins in a coordinated fashion. In contrast, top-down MS analyzes intact proteins and reveals PTM patterns along the entire proteins. However, while recent advances in instrumentation have made top-down MS accessible to many laboratories, most computational tools for top-down MS focus on proteins with few PTMs and are unable to identify complex PTM patterns. We propose a new algorithm, MS-Align-E, that identifies both expected and unexpected PTMs in ultramodified proteins. We demonstrate that MS-Align-E identifies many protein forms of histone H4 and benchmark it against the currently accepted software tools.

Environmental Molecular Sciences Laboratory↗
DOE OSTI2018

Nanoporous aramid nanofibre separators for nonaqueous redox flow batteries

Abstract Redox flow batteries are attractive for large-scale energy storage due to a combination of high theoretical efficiencies and decoupled power and energy storage capacities. Efforts to significantly increase energy densities by using nonaqueous electrolytes have been impeded by separators with low selectivities. Here, we report nanoporous separators based on aramid nanofibres, which are assembled using a scalable, low cost, spin-assisted layer-by-layer technique. The multilayer structure yields 5 ± 0.5 nm pores, enabling nanofiltration with high selectivity. Further, surface modifications using polyelectrolytes result in enhanced performance. In vanadium acetylacetonate/acetonitrile-based electrolytes, the coated separator exhibits permeabilities an order of magnitude lower and ionic conductivities five times higher than those of a commercial separator. In addition, the coated separators exhibit exceptional stability, showing minimal degradation after more than 100 h of cycling. The low permeability translates into high coulombic efficiency in flow cell charge/discharge experiments performed at cycle times relevant for large-scale applications (5 h).

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2020

Porous cage-derived nanomaterial inks for direct and internal three-dimensional printing

The convergence of 3D printing techniques and nanomaterials is generating a compelling opportunity space to create advanced materials with multiscale structural control and hierarchical functionalities. While most nanoparticles consist of a dense material, less attention has been payed to 3D printing of nanoparticles with intrinsic porosity. Here, we combine ultrasmall (about 10 nm) silica nanocages with digital light processing technique for the direct 3D printing of hierarchically porous parts with arbitrary shapes, as well as tunable internal structures and high surface area. Thanks to the versatile and orthogonal cage surface modifications, we show how this approach can be applied for the implementation and positioning of functionalities throughout 3D printed objects. Furthermore, taking advantage of the internal porosity of the printed parts, an internal printing approach is proposed for the localized deposition of a guest material within a host matrix, enabling complex 3D material designs.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Microphysical properties of atmospheric soot and organic particles: measurements, modeling, and impacts

Atmospheric soot and organic particles from fossil fuel combustion and biomass burning modify Earth’s climate through their interactions with solar radiation and through modifications of cloud properties by acting as cloud condensation nuclei and ice nucleating particles. Recent advancements in understanding their individual properties and microscopic composition have led to heightened interest in their microphysical properties. This review article provides an overview of current advanced microscopic measurements and offers insights into future avenues for studying microphysical properties of these particles. To quantify soot morphology and ageing, fractal dimension ( D f ) is a commonly employed quantitative metric which allows to characterize morphologies of soot aggregates and their modifications in relation to ageing factors like internal mixing state, core-shell structures, phase, and composition heterogeneity. Models have been developed to incorporate D f and mixing diversity metrics of aged soot particles, enabling quantitative assessment of their optical absorption and radiative forcing effects. The microphysical properties of soot and organic particles are complex and they are influenced by particle sources, ageing process, and meteorological conditions. Furthermore, soluble organic particles exhibit diverse forms and can engage in liquid–liquid phase separation with sulfate and nitrate components. Primary carbonaceous particles such as tar balls and soot warrant further attention due to their strong light absorbing properties, presence of toxic organic constituents, and small size, which can impact human health. Future research needs include both atmospheric measurements and modeling approaches, focusing on changes in the mixing structures of soot and organic particle ensembles, their effects on climate dynamics and human health.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2014

Structure of the near-surface layer of NiTi on the meso- and microscale levels after ion-beam surface treatment

Using the EBSD, SEM and TEM methods, the structure of surface layer of polycrystalline NiTi alloy samples was examined after the modification of material surface by the pulsed action of mean-energy silicon ion beam. It was found that the ion beam treatment would cause grain fragmentation of the near-surface layer to a depth 5÷50 μm; a higher extent of fragmentation was observed in grains whose close-packed planes were oriented approximately in the same direction as the ion beam was. The effect of high-intensity ion beam treatment on the anisotropic behavior of polycrystalline NiTi alloy and the mechanisms involved were also examined.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2015

Solving the excitation and chemical abundances in shocks: The case of HH 1

We present deep spectroscopic (3600–24700 Å ) X-shooter observations of the bright Herbig–Haro object HH 1, one of the best laboratories to study the chemical and physical modifications caused by protostellar shocks on the natal cloud. We observe atomic fine structure lines, H i and He i recombination lines and H{sub 2} ro-vibrational lines (more than 500 detections in total). Line emission was analyzed by means of Non-local Thermal Equilibiurm codes to derive the electron temperature and density, and for the first time we are able to accurately probe different physical regimes behind a dissociative shock. We find a temperature stratification in the range 4000 K ÷ 80,000 K, and a significant correlation between temperature and ionization energy. Two density regimes are identified for the ionized gas, a more tenuous, spatially broad component (density ∼10{sup 3} cm{sup −3}), and a more compact component (density ⩾ 10{sup 5} cm{sup −3}) likely associated with the hottest gas. A further neutral component is also evidenced, having a temperature ≲10,000 K and a density >10{sup 4} cm{sup −3}. The gas fractional ionization was estimated by solving the ionization equilibrium equations of atoms detected in different ionization stages. We find that neutral and fully ionized regions co-exist inside the shock. Also, indications in favor of at least partially dissociative shock as the main mechanism for molecular excitation are derived. Chemical abundances are estimated for the majority of the detected species. On average, abundances of non-refractory/refractory elements are lower than solar of about 0.15/0.5 dex. This indicates the presence of dust inside the medium, with a depletion factor of iron of ∼40%.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2023

Parameter dependencies of the separatrix density in low triangularity L-mode and H-mode JET-ILW plasmas

Abstract The midplane electron separatrix density, n e,sep , in JET-ILW L-mode and H-mode low triangularity deuterium fuelled plasmas exhibits a strong explicit dependence on the averaged outer divertor target electron temperature, n e,sep ∼ T e,ot −1/2 . This dependence is reproduced by analytic reversed two point model (rev-2PM), and arises from parallel pressure balance, as well as the ratio of the power and momentum volumetric loss factors, (1 − f cooling )/(1 − f mom-loss ). Quantifying the influence of the (1 − f cooling ) and (1 − f mom-loss ) loss factors on n e,sep has been enabled by measurement estimates of these quantities from L-mode density (fueling) ramps in the outer horizontal, VH(C), and vertical target, VV, divertor configurations. Rev-2PM n e,sep estimates from the extended H-mode and more limited L-mode datasets are recovered to within ±25% of the measurements, with a scaling factor applied to account for use of T e,ot , an averaged quantity, rather than flux tube resolved target values. Both the (1 − f cooling ) and (1 − f mom-loss ) trends and recovery of n e,sep using the rev-2PM formatting are reproduced in EDGE2D-EIRENE L-mode-like and H-mode-like density scan simulations. The general lack of a divertor configuration effect in the JET-ILW n e,sep trends can be attributed to a significant influence of main chamber recycling, which has been shown in the EDGE2D-EIRENE results to moderate n e,sep with respect to changes in divertor neutral leakage imposed by changes in the divertor configuration. The unified n e,sep vs T e,ot trends can, however, be broken if large modifications to the divertor geometry (e.g. complete removal of the outer divertor baffle structure) are introduced in the model. The more pronounced high-field side high density region formation in the VH(C) configuration with reduced clearance to the separatrix does not appear to have a significant influence on the outer midplane separatrix and pedestal parameters when mapped to T e,ot , although conditions at the inner midplane could not be assessed.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗