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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 271 records · Page 15
All sourcesNASA NTRSDOE OSTI
DOE OSTI2014

Monte Carlo calculations of electron beam quality conversion factors for several ion chamber types

Purpose: To provide a comprehensive investigation of electron beam reference dosimetry using Monte Carlo simulations of the response of 10 plane-parallel and 18 cylindrical ion chamber types. Specific emphasis is placed on the determination of the optimal shift of the chambers’ effective point of measurement (EPOM) and beam quality conversion factors. Methods: The EGSnrc system is used for calculations of the absorbed dose to gas in ion chamber models and the absorbed dose to water as a function of depth in a water phantom on which cobalt-60 and several electron beam source models are incident. The optimal EPOM shifts of the ion chambers are determined by comparing calculations of R{sub 50} converted from I{sub 50} (calculated using ion chamber simulations in phantom) to R{sub 50} calculated using simulations of the absorbed dose to water vs depth in water. Beam quality conversion factors are determined as the calculated ratio of the absorbed dose to water to the absorbed dose to air in the ion chamber at the reference depth in a cobalt-60 beam to that in electron beams. Results: For most plane-parallel chambers, the optimal EPOM shift is inside of the active cavity but different from the shift determined with water-equivalent scaling of the front window of the chamber. These optimal shifts for plane-parallel chambers also reduce the scatter of beam quality conversion factors, k{sub Q}, as a function of R{sub 50}. The optimal shift of cylindrical chambers is found to be less than the 0.5 r{sub cav} recommended by current dosimetry protocols. In most cases, the values of the optimal shift are close to 0.3 r{sub cav}. Values of k{sub ecal} are calculated and compared to those from the TG-51 protocol and differences are explained using accurate individual correction factors for a subset of ion chambers investigated. High-precision fits to beam quality conversion factors normalized to unity in a beam with R{sub 50} = 7.5 cm (k{sub Q}{sup ′}) are provided. These factors avoid the use of gradient correction factors as used in the TG-51 protocol although a chamber dependent optimal shift in the EPOM is required when using plane-parallel chambers while no shift is needed with cylindrical chambers. The sensitivity of these results to parameters used to model the ion chambers is discussed and the uncertainty related to the practical use of these results is evaluated. Conclusions: These results will prove useful as electron beam reference dosimetry protocols are being updated. The analysis of this work indicates that cylindrical ion chambers may be appropriate for use in low-energy electron beams but measurements are required to characterize their use in these beams.

07 ISOTOPE AND RADIATION SOURCES↗
DOE OSTI2017

Constraining the relative velocity effect using the Baryon Oscillation Spectroscopic Survey

Here, we analyse the power spectrum of the Baryon Oscillation Spectroscopic Survey (BOSS) Data Release 12 to constrain the relative velocity effect, which represents a potential systematic for measurements of the baryon acoustic oscillation (BAO) scale. The relative velocity effect is sourced by the different evolution of baryon and cold dark matter perturbations before decoupling. Our power spectrum model includes all one-loop redshift-space terms corresponding to vbc parametrized by the bias parameter b$2\atop{v}$ . We also include the linear terms proportional to the relative density, δbc, and relative velocity dispersion, θbc, which we parametrize with the bias parameters b$bc\atop{δ}$ and b$bc\atop{θ}$. This data does not support a detection of the relative velocity effect in any of these parameters. Combining the low- and high-redshift bins of BOSS, we find limits of b$2\atop{v}$=0.012±0.015(±0.031) , b$bc\atop{δ}$=-1.0±2.5(±6.2) and b$bc\atop{θ}$=-114±55(±175) with 68 percent (95 percent) confidence levels. These constraints restrict the potential systematic shift in D A (z), H(z) and fσ8, due to the relative velocity, to 1 percent, 0.8 percent and 2 percent, respectively. Given the current uncertainties on the BAO measurements of BOSS, these shifts correspond to 0.53σ, 0.5σ and 0.22σ for DA(z), H(z) and fσ8, respectively.

77 NANOSCIENCE AND NANOTECHNOLOGY↗
DOE OSTI2024

Highly efficient La/Ni co-doped strontium titanate catalyst for co-production of propylene and hydrogen from propane in protonic ceramic electrochemical cells

A highly efficient La/Ni co-doped strontium titanate (LSNT) perovskite catalyst is developed and integrated in a protonic ceramic electrochemical cell for co-production of propylene and high-purity hydrogen from commercial propane feedstock. Propane conversion and hydrogen production rate can be effectively enhanced under an applied current due to the electrochemical promotion effect and/or shifted reaction equilibrium induced by rapid separation of hydrogen product. Water vapor in the feed gas could significantly improve the catalyst stability by suppressing the coke formation. The propane conversion could reach up to 53% at 600 °C under a current density of 90 mA cm −2 . The LSNT catalyst also shows excellent tolerance for the sulfur contaminant in commercial propane gas. Finally, the excellent performance of the LSNT catalyst is attributed to the highly active and selective Ni species at the interface with the perovskite substrate, which are formed in situ via reduction-induced exsolution under reaction conditions.

interfacial active sites↗
DOE OSTI2013

Application of wire beam electrode technique to investigate initiation and propagation of rebar corrosion

Multi-electrode technique named as wire beam electrode (WBE) was used to study pitting corrosion of rebar under concrete cover. When WBE embedded mortar sample was immersed in NaCl solution, uneven distributions of galvanic current and open circuit potential (OCP) on the WBE were observed due to the initiation of pitting corrosion. The following oxygen depletion in mortar facilitated the negative shift of the OCP and the smoothing of the current and potential distributions. Wetting–drying cycle experiments showed that corrosion products instead of oxygen in wet mortar specimen sustained the propagation of pitting corrosion due to Fe (III) taking part in cathodic depolarization during oxygen-deficient wet period, which was confirmed by micro-Raman spectroscopy. In addition, new pitting corrosion occurred mainly near the corrosion products, leading to preferentially horizontal propagation of rust layer on the WBE. A localized corrosion factor was further presented to quantify the localised corrosion based on galvanic current maps.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Analysis of TID process, geometry, and bias condition dependence in 14-nm FinFETs and implications for RF and SRAM performance

Here, total ionizing dose results are provided, showing the effects of different threshold adjust implant processes and irradiation bias conditions of 14-nm FinFETs. Minimal radiation-induced threshold voltage shift across a variety of transistor types is observed. Off-state leakage current of nMOSFET transistors exhibits a strong gate bias dependence, indicating electrostatic gate control of the sub-fin region and the corresponding parasitic conduction path are the largest concern for radiation hardness in FinFET technology. The high-Vth transistors exhibit the best irradiation performance across all bias conditions, showing a reasonably small change in off-state leakage current and Vth, while the low-Vth transistors exhibit a larger change in off-state leakage current. The “worst-case” bias condition during irradiation for both pull-down and pass-gate nMOSFETs in static random access memory is determined to be the on-state (Vgs = Vdd). We find the nMOSFET pull-down and pass-gate transistors of the SRAM bit-cell show less radiation-induced degradation due to transistor geometry and channel doping differences than the low-Vth transistor. Near-threshold operation is presented as a methodology for reducing radiation-induced increases in off-state device leakage current. In a 14-nm FinFET technology, the modeling indicates devices with high channel stop doping show the most robust response to TID allowing stable operation of ring oscillators and the SRAM bit-cell with minimal shift in critical operating characteristics.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2016

Raman shifts in electron-irradiated monolayer MoS 2

Here, we report how the presence of electron-beam-induced sulfur vacancies affects first-order Raman modes and correlate the effects with the evolution of the in situ transmission-electron microscopy (TEM) two-terminal conductivity of monolayer MoS 2 under electron irradiation. We observe a redshift in the E Raman peak and a less pronounced blueshift in the A' 1 peak with increasing electron dose. Using energy-dispersive X-ray spectroscopy (EDS), we show that irradiation causes partial removal of sulfur and correlate the dependence of the Raman peak shifts with S vacancy density (a few %), which is confirmed by first-principles density functional theory calculations. In situ device current measurements show exponential decrease in channel current upon irradiation. Our analysis demonstrates that the observed frequency shifts are intrinsic properties of the defective systems and that Raman spectroscopy can be used as a quantitative diagnostic tool to characterize MoS 2 -based transport channels.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2013

Advanced Models of LWR Pressure Vessel Embrittlement for Low Flux-High Fluence Conditions

Neutron embrittlement of reactor pressure vessels (RPVs) is an unresolved issue for light water reactor life extension, especially since transition temperature shifts (TTS) must be predicted for high 80-year fluence levels up to approximately 1,020 n/cm 2 , far beyond the current surveillance database. Unfortunately, TTS may accelerate at high fluence, and may be further amplified by the formation of late blooming phases that result in severe embrittlement even in low-copper (Cu) steels. Embrittlement by this mechanism is a potentially significant degradation phenomenon that is not predicted by current regulatory models. This project will focus on accurately predicting transition temperature shifts at high fluence using advanced physically based, empirically validated and calibrated models. A major challenge is to develop models that can adjust test reactor data to account for flux effects. Since transition temperature shifts depend on synergistic combinations of many variables, flux-effects cannot be treated in isolation. The best current models systematically and significantly under-predict transition temperature at high fluence, although predominantly for irradiations at much higher flux than actual RPV service. This project will integrate surveillance, test reactor and mechanism data with advanced models to address a number of outstanding RPV embrittlement issues. The effort will include developing new databases and preliminary models of flux effects for irradiation conditions ranging from very low (e.g., boiling water reactor) to high (e.g., accelerated test reactor). The team will also develop a database and physical models to help predict the conditions for the formation of Mn-Ni-Si late blooming phases and to guide future efforts to fully resolve this issue. Researchers will carry out other tasks on a best-effort basis, including prediction of transition temperature shift attenuation through the vessel wall, remediation of embrittlement by annealing, and fracture toughness master curve issues.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
DOE OSTI2026

Temperature-Dependent Transport Characteristics of 2D MoS2 Channel FETs Grown Using Salt-Based Precursors

D Transition Metal Dichalcogenides (TMDs), particularly MoS2, are promising candidates for sub-10 nm Gate All Around (GAA) CMOS FETs. Salt-assisted Chemical Vapor Deposition (CVD) enable lateral MoS2 growth at atmospheric pressure and low temperatures. This work analyzes salt-based precursor-driven CVD-grown MoS2 FETs at various temperatures. MoS2 was grown using Ammonium Molybdate salt, sulfurized at 750∘C, and transferred onto p−Si3/SiO2 substrates. At room temperature, threshold voltage (VT) ranged from -35 V to -25 V, with a peak drain current of 1.2μA/μm. As temperature increased above 325K, VT shifted exponentially, and carrier mobility dropped significantly. At 400 K, the gate lost channel control, though gate leakage current remained low. These results are compared with non-salt-based MoS2 growth to assess salt precursor effects.Notice: This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the US Department of Energy (DOE). The US government retains and the publisher, by accepting the article for publication, acknowledges that the US government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for US government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan (https://www.energy.gov/doe-public-access-plan).

Jones, Andrew [ORNL] (ORCID:0009000233849687)↗
DOE OSTI2017

Impact of E × B shear flow on low-n MHD instabilities

Recently, the stationary high confinement operations with improved pedestal conditions have been achieved in DIII-D [K. H. Burrell et al., Phys. Plasmas 23, 056103 (2016)], accompanying the spontaneous transition from the coherent edge harmonic oscillation (EHO) to the broadband MHD turbulence state by reducing the neutral beam injection torque to zero. It is crucial for the burning plasma devices such as ITER. Simulations about the effects of E×B shear flow on the quiescent H-mode (QH-mode) are carried out using the three-field two-fluid model in the field-aligned coordinate under the BOUT++ framework. Using the shifted circular cross-section equilibriums including bootstrap current, the results demonstrate that the E×B shear flow strongly destabilizes low-n peeling modes, which are mainly driven by the gradient of parallel current in peeling-dominant cases and are sensitive to the E r shear. Adopting the much more general shape of E×B shear (ω E =E r /RB θ ) profiles, the linear and nonlinear BOUT++ simulations show qualitative consistence with the experiments. The stronger shear flow shifts the most unstable mode to lower-n and narrows the mode spectrum. At the meantime, the nonlinear simulations of the QH-mode indicate that the shear flow in both co- and counter directions of diamagnetic flow has some similar effects. The nonlinear mode interaction is enhanced during the mode amplitude saturation phase. These findings reveal that the fundamental physics mechanism of the QH-mode may be shear flow and are significant for understanding the mechanism of EHO and QH-mode.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2019

Is the subtropical jet shifting poleward?

The tropics are expanding poleward at about 0.5° per decade in observations. This poleward expansion of the circulation is consistently reported using Hadley cell edge metrics and lower-atmospheric tropical edge metrics. However, some upper-atmospheric tropical metrics report smaller trends that are often not significant. One such upper-atmospheric metric is the subtropical jet latitude, which has smaller trends compared to the Hadley cell edge. In this study we investigate the robustness of the weak trends in the subtropical jet position by introducing a new method for locating the subtropical jet, and examining the trends and variability of the subtropical jet latitude. We introduce the tropopause gradient method based on the peak gradient in potential temperature along the dynamic tropopause. Using this method we find the trends in the subtropical jet latitude are indeed much smaller than 0.5° per decade, consistent with previous studies. We also find that natural variability within the subtropical jet latitude would not prevent trends from being detected if they were similar to the Hadley cell edge, as trends greater than 0.24° per decade could reliably be detected using monthly data or 0.09° per decade using daily data. Despite the poleward expansion of the tropics, there is no robust evidence to suggest the subtropical jet is shifting poleward in either hemisphere. Neither the current diagnostic methods nor natural variability can account for the small subtropical jet trends. The most likely explanation, which requires further investigation, is that the subtropical jet position is not tied dynamically to the Hadley cell edge.

Maher, Penelope↗
DOE OSTI2018

Electrochemical Behavior of Mg-Al-Zn-Ga Alloy as Anode Materials in 3.5 wt.% NaCl Solution

The microstructure and electrochemical behaviors of Mg-Al-Zn and Mg-Al-Zn-Ga alloys as anode materials were investigated by morphology observation, composition analysis, phase identification, and electrochemical tests. The experimental results suggest that Ga alloying can refine the grains of the Mg-Al-Zn alloy by promoting second-phase segregation, which comprises Mg{sub 17}Al{sub 12} and GaMg{sub 2}. The comparison of discharge tests indicates that adding Ga to the Mg-Al-Zn alloy can negatively shift the discharge potential, provide a high current density, promote the formation of tiny and thin products, and improve the utilization efficiency. Meanwhile, the addition of Ga can increase the corrosion resistance of Mg-Al-Zn alloy because the Ga alloying promotes the segregation of the intermetallic phases in the Mg matrix. The intermetallic phases disperse in isolate states in the Mg matrix, resulting in their falling off from the substrate once their adjacent Mg is exhausted and subsequently ceasing the micro-galvanic corrosion. The Mg-Al-Zn-Ga alloy with higher corrosion resistance performs better discharge activity than that of Mg-Al-Zn alloy in 3.5 wt.% NaCl solution, implying that the Mg-Al-Zn-Ga alloy is a promising anode material for seawater-activated battery.

36 MATERIALS SCIENCE↗
DOE OSTI2014

Assessing corporate project impacts in changeable contexts: A human rights perspective

Project-level impact assessment was originally conceived as a snapshot taken in advance of project implementation, contrasting current conditions with a likely future scenario involving a variety of predicted impacts. Current best practice guidance has encouraged a shift towards longitudinal assessments from the pre-project stage through the implementation and operating phases. Experience and study show, however, that assessment of infrastructure-intensive projects rarely endures past the project's construction phase. Negative consequences for environmental, social and health outcomes have been documented. Such consequences clarify the pressing need for longitudinal assessment in each of these domains, with human rights impact assessment (HRIA) as an umbrella over, and critical augmentation of, environmental, social and health assessments. Project impacts on human rights are more closely linked to political, economic and other factors beyond immediate effects of a company's policy and action throughout the project lifecycle. Delineating these processes requires an adequate framework, with strategies for collecting longitudinal data, protocols that provide core information for impact assessment and guidance for adaptive mitigation strategies as project-related effects change over time. This article presents general principles for the design and implementation of sustained, longitudinal HRIA, based on experience assessing and responding to human rights impact in a uranium mining project in Malawi. The case study demonstrates the value of longitudinal assessment both for limiting corporate risk and improving human welfare. - Graphical abstract: Assessing changes in human rights condition as affected by both project and context, over time. - Highlights: • Corporate capital projects affect human rights in myriad ways. • Ongoing, longitudinal impact assessment techniques are needed. • We present an approach for conducting longitudinal human rights impact assessment. • Our methodology allows distinguishing corporate impacts from contextual changes. • Promptly observing context changes and impacts enables companies to react nimbly.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2014

Effects of isomorphous substitution of a coordination polymer on the properties and its application in electrochemical sensing

This work concerns the isomorphous substitution of coordination polymers (CPs) and its effect on the optical and electrochemical properties. The application of CPs in electrochemical sensing was studied as well. Isomorphous coordination polymers, [Co{sub x}Zn{sub 1−x}tyr]{sub n} (tyr=L-tyrosine), where x (0–1) was controlled by the Co/Zn ratios of raw materials, were successfully synthesized via a hydrothermal method, as proved by XRD and EDS results. Their UV–vis DRS and fluorescence spectra change gradually along with the composition. Cyclic voltammograms of modified electrodes, [Co{sub x}Zn{sub 1−x}tyr]{sub n}/GCE, show that as more and more Zn replaced Co, the current signal decreases greatly and the potential shifts negatively. Much attention was paid to [Cotyr]{sub n} due to its highest sensitivity. Refreshable modified carbon paste electrode, [Cotyr]{sub n}-CPE, was used to determine nitrite, and showed pretty good performance as evidenced by chronoamperometry. The response was made very fast within mere 5 s. The linear detection range was from 5.00×10{sup −5} to 3.45×10{sup −3} M, with sensitivity of 263.4 mA mol{sup −1} L cm{sup −2}. The detection limit was found to be 2.00×10{sup −5} M. The sensor also showed good antiinterference and reproducibility. - Graphical abstract: Evolution of the optical and electrochemical properties of isomorphic coordination polymers [Co{sub x}Zn{sub 1−x}tyr]{sub n} along with the changing of x was studied. The CP also showed perfect performance in the electrochemical determination of nitrite. - Highlights: • Isomorphous substitution of coordination polymers (CPs). • Substitution-caused evolution of optical and electrochemical properties of CPs. • Application of CPs in electrochemical sensing, an incipient area. • Perfect performance of CPs in electrochemical determination of nitrite.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2012

Electron spectrometer in adjustable triode configuration for photo-induced field emission measurements

We have constructed a new ultrahigh vacuum apparatus with a triode configuration for the systematic investigation of photo-induced field emission (PFE) from metallic or semiconducting cathodes. These are exposed to electric fields up to 400 MV/m and laser irradiation by means of hole or mesh gates. Cathodes and gates are in situ exchangeable and adjustable with high precision to ensure a homogeneous extraction of electrons which are partially transmitted to the fixed electron spectrometer. Its hemispherical sector analyzer provides an energy resolution limit of 8 meV. The commissioning of the measurement system has been performed with a tungsten needle. Its temperature showed up in the high-energy tail of the electron spectrum, while its work function was derived from the spectral low-energy part combined with the integral current-voltage curve. First PFE measurements on B-doped Si-tip arrays yielded a small field emission current increase under green laser illumination. A shift and splitting of the energy spectra was observed which revealed different emission regimes as well as the photosensitivity of the cathode due to carrier excitation into the conduction band. For the full exploitation of the PFE system, a tunable laser over a wide eV-range is required.

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
DOE OSTI2015

The Fowler-Nordheim behavior and mechanism of photo-sensitive field from SnS{sub 2} nanosheets

Here in, we report photo-sensitive field emission measurements of SnS{sub 2} nanosheets at base pressure of ∼1×10{sup −8} mbar are reported. The nonlinear Fowler-Nordheim (F-N) plot is elucidate according to a (F-N) model of calculation based on shift in a saturation of conduction band current density after light illumination and prevalence of valence band current density at high electric field values. The model of calculation suggests that the slope variation before and after visible light illumination of the F-N plot, in the high-field and low-field regions, does not depend on the magnitude of saturation but also depend on charge carrier (electron) concentration get increased in conduction band. The F-N model of calculation is important for the fundamental understanding of the photo-sensitive field emission mechanism of semiconducting SnS{sub 2}. The replicate F-N plots exhibit similar features to those observed experimentally. The model calculation suggests that the nonlinearity of the F-N plot is a characteristic of the photo-enhanced energy band structure of the photo-sensitive semiconductor material.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2015

Stability of standing spin wave in permalloy thin film studied by anisotropic magnetoresistance effect

We have investigated the stability for the resonant spin precession under the strong microwave magnetic field by a specially developed detection method using the anisotropic magnetoresistance effect. The electrically separated excitation and detection circuits enable us to investigate the influence of the heating effect and the nonuniform spin dynamics independently. The large detecting current is found to induce the field shift of the resonant spectra because of the Joule heating. From the microwave power dependence, we found that the linear response regime for the standing spin wave is larger than that for the ferromagnetic resonance. This robust characteristic of the standing spin wave is an important advantage for the high power operation of the spin-wave device.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2017

Effect of scrape-off-layer current on reconstructed tokamak equilibrium

Methods are described that extend fields from reconstructed equilibria to include scrape-off-layer current through extrapolated parametrized and experimental fits. The extrapolation includes both the effects of the toroidal-field and pressure gradients which produce scrape-off-layer current after recomputation of the Grad-Shafranov solution. To quantify the degree that inclusion of scrape-off-layer current modifies the equilibrium, the χ-squared goodness-of-fit parameter is calculated for cases with and without scrape-off-layer current. The change in χ-squared is found to be minor when scrape-off-layer current is included however flux surfaces are shifted by up to 3 cm. Here the impact on edge modes of these scrape-off-layer modifications is also found to be small and the importance of these methods to nonlinear computation is discussed.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2016

Global and pedestal confinement and pedestal structure in dimensionless collisionality scans of low-triangularity H-mode plasmas in JET-ILW

A dimensionless collisionality scan in low-triangularity plasmas in the Joint European Torus with the ITER-like wall (JET-ILW) has been performed. The increase of the normalized energy confinement (defined as the ratio between thermal energy confinement and Bohm confinement time) with decreasing collisionality is observed. Moreover, at low collisionality, a confinement factor H98, comparable to JET-C, is achieved. At high collisionality, the low normalized confinement is related to a degraded pedestal stability and a reduction in the density-profile peaking.The increase of normalized energy confinement is due to both an increase in the pedestal and in the core regions. The improvement in the pedestal is related to the increase of the stability. The improvement in the core is driven by (i) the core temperature increase via the temperature-profile stiffness and by (ii) the density-peaking increase driven by the low collisionality.Pedestal stability analysis performed with the ELITE (edge-localized instabilities in tokamak equilibria) code has a reasonable qualitative agreement with the experimental results. An improvement of the pedestal stability with decreasing collisionality is observed. The improvement is ascribed to the reduction of the pedestal width, the increase of the bootstrap current and the reduction of the relative shift between the positions of the pedestal density and pedestal temperature.The EPED1 model predictions for the pedestal pressure height are qualitatively well correlated with the experimental results. Quantitatively, EPED1 overestimates the experimental pressure by 15–35%. In terms of the pedestal width, a correct agreement (within 10–15%) between the EPED1 and the experimental width is found at low collisionality. The experimental pedestal width increases with collisionality. Nonetheless, an extrapolation to low-collisionality values suggests that the width predictions from the KBM constraint are reasonable for ITER.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗