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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 1,585 records · Page 88
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Search For Electron-Antineutrinos Associated With 2 Gravitational-Wave Events GW150914, GW151012, GW151226, 3 GW170104, GW170608, GW170814, and GW170817 at Daya Bay

Providing a possible connection between neutrino emission and gravitational-wave (GW) bursts is important to our understanding of the physical processes that occur when black holes or neutron stars merge. In the Daya Bay experiment, using the data collected from December 2011 to August 2017, a search has been performed for electron-antineutrino signals coinciding with detected GW events, including GW150914, GW151012, GW151226, GW170104, GW170608, GW170814, and GW170817. We used three time windows of ±10 s, ±500 s, and ±1000 s relative to the occurrence of the GW events, and a neutrino energy range of 1.8 to 100 MeV to search for correlated neutrino candidates. The detected electron-antineutrino candidates are consistent with the expected background rates for all the three time windows. Assuming monochromatic spectra, we found upper limits (90% confidence level) on electron-antineutrino fluence of (1.13 - 2.44)×1011 cm-2 at 5 MeV to 8.0×107cm-2at 100 MeV for the three timewindows. Under the assumption of a Fermi-Dirac spectrum, the upper limits were found to be (5.4 - 7.0)×109 cm-2 for the three time windows.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2021

Search for the doubly heavy baryons $ {{{{\varOmega}_{bc}^{0}}}} $ and $ {{{{\varXi}_{bc}^{0}}}} $ decaying to $ {{{{\varLambda}^+_c}}} {{{{\pi}^-}}} $ and $ {{{{\varXi}^+_c}}} {{{{\pi}^-}}} $ *

The first search for the doubly heavy $ {{{{\varOmega}_{bc}^{0}}}} $ baryon and a search for the $ {{{{\varXi}_{bc}^{0}}}} $ baryon are performed using $ pp $ collision data collected via the $ {\rm{LHCb}} $ experiment from 2016 to 2018 at a centre-of-mass energy of $ 13 \;{\rm{TeV}} $, corresponding to an integrated luminosity of 5.2 $ \;{\rm{f}}{{\rm{b}}^{ - 1}} $. The baryons are reconstructed via their decays to $ {{{{\varLambda}^+_c}}} {{{{\pi}^-}}} $ and $ {{{{\varXi}^+_c}}} {{{{\pi}^-}}} $. No significant excess is found for invariant masses between 6700 and 7300 $ \;{\rm{MeV}}/{c^2} $, in a rapidity range from 2.0 to 4.5 and a transverse momentum range from 2 to 20 $ \;{\rm{MeV}}/{c} $. Upper limits are set on the ratio of the $ {{{{\varOmega}_{bc}^{0}}}} $ and $ {{{{\varXi}_{bc}^{0}}}} $ production cross-section times the branching fraction to $ {{{{\varLambda}^+_c}}}{{{{\pi}^-}}} $ ( $ {{{{\varXi}^+_c}}}{{{{\pi}^-}}} $) relative to that of the $ {{{{\varLambda}^0_b}}} $ ( $ {{{{\varXi}_{b}^{0}}}} $) baryon, for different lifetime hypotheses, at 95% confidence level. The upper limits range from $ 0.5\times10^{-4} $ to $ 2.5\times10^{-4} $ for the $ {{{{{{{{\varOmega}_{bc}^{0}}}}{{\rightarrow }}{{{{\varLambda}^+_c}}}{{{{\pi}^-}}}}}}} $ ( $ {{{{{{{{\varXi}_{bc}^{0}}}}{{\rightarrow }}{{{{\varLambda}^+_c}}}{{{{\pi}^-}}}}}}} $) decay, and from $ 1.4\times10^{-3} $ to $ 6.9\times10^{-3} $ for the $ {{{{{{{{\varOmega}_{bc}^{0}}}}{{\rightarrow }}{{{{\varXi}^+_c}}}{{{{\pi}^-}}}}}}} $ ( $ {{{{{{{{\varXi}_{bc}^{0}}}}{{\rightarrow }}{{{{\varXi}^+_c}}}{{{{\pi}^-}}}}}}} $) decay, depending on the considered mass and lifetime of the $ {{{{\varOmega}_{bc}^{0}}}} $ ( $ {{{{\varXi}_{bc}^{0}}}} $) baryon.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2022

Search for the weak decay ψ (3686) → $Λ^{+}_{c}$ $\overline{Σ}$ - + c.c. *

Using (448.1 ± 2.9) x 10 6 ψ (3686) events collected with the BESIII detector, we perform the first search for the weak baryonic decay ψ (3686) → $Λ^{+}_{c}$ $\overline{Σ}$ - + c.c. . The analysis procedure is optimized using a blinded method. No significant signal is observed, and the upper limit on the branching fraction ($\mathcal{B}$) of ψ (3686) → $Λ^{+}_{c}$ $\overline{Σ}$ - + c.c. is set as 1.4 x 10 -5 at the 90% confidence level.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2022

Search for hidden-charm tetraquark with strangeness in e + e - → $K$ + $D^{*}_{s}$ - $D$ *0 + c.c.*

We report a search for a heavier partner of the recently observed Z cs (3985) - state, denoted as $Z^{'-}_{cs}$, in the process e + e - → $K$ + $D^{*}_{s}$ - $D$ *0 + c.c., based on e + e - collision data collected at the center-of-mass energies of $\sqrt{s}$ = 4.661, 4.682 and 4.699 GeV with the BESIII detector. The $Z^{'-}_{cs}$ is of interest as it is expected to be a candidate for a hidden-charm and open-strange tetraquark. A partial-reconstruction technique is used to isolate K + recoil-mass spectra, which are probed for a potential contribution from $Z^{'-}_{cs}$ → $D^{*}_{s}$ - $D$ *0 + (c.c.). We find an excess of $Z^{'-}_{cs}$ → $D^{*}_{s}$ - $D$ *0 + (c.c.) candidates with a significance of 2.1σ, after considering systematic uncertainties, at a mass of 4123.5 ± 0.7 stat. ± 4.7 syst. ) MeV/c 2 . As the data set is limited in size, the upper limits are evaluated at the 90% confidence level on the product of the Born cross sections (σ BORN ) and the branching fraction ($\mathcal{B}$) of $Z^{'-}_{cs}$ → $D^{*}_{s}$ - $D$ *0 , under different assumptions of the $Z^{'-}_{cs}$ mass from 4.120 to 4.140 MeV and of the width from 10 to 50 MeV at the three center-of-mass energies. The upper limits of σ BORN ∙ $\mathcal{B}$ are found to be at the level of $\mathcal{O}$(1) pb at each energy. Larger data samples are needed to confirm the $Z^{'-}_{cs}$ state and clarify its nature in the coming years.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2023

Searching for the axion-like particle at the EIC*

Abstract The axion-like particle (ALP) is a well motivated new particle candidate for beyond the standard model. In this study, we propose to probe the ALP via photon fusion scattering at the upcoming Electron-Ion Collider (EIC) with electron and proton energies of and , respectively. We can constrain the effective coupling strength between the ALP and photons to be at the confidence level with an integrated luminosity of for the mass range . Such bounds may be significantly improved if we consider the nucleus beam at the EIC. We also demonstrate that the limits from the EIC can be stronger than the off Z -pole measurement at the LEP and light-by-light scattering with pp collisions at the LHC.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2023

Search for the rare decays $W^+ → D^+_s \gamma$ and $Z → D^0 \gamma$ at LHCb

A search for the rare decays $W^+ → D^+_s \gamma$ and $Z → D^0 \gamma$ is performed using proton-proton collision data collected by the LHCb experiment at a centre-of-mass energy of 13TeV, corresponding to an integrated luminosity of 2.0fb -1 . No significant signal is observed for either decay mode and upper limits on their branching fractions are set using W⁺ → μ⁺v and Z → μ⁺μ⁻ decays as normalization channels. The upper limits are 6.5 x 10 -4 and 2.1 x 10 -3 at 95% confidence level for the $W^+ → D^+_s \gamma$ and $Z → D^0 \gamma$ decay modes, respectively. This is the first reported search for the $Z → D^0 \gamma$ decay, while the upper limit on the branching fraction $W^+ → D^+_s \gamma$ improves upon the previous best limit.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2025

Bayesian inference of nuclear incompressibility from collective flow in mid-central Au+Au collisions at 400–1500 MeV/nucleon

The incompressibility K of symmetric nuclear matter (SNM) is determined through a Bayesian analysis of collective flow data from Au + Au collisions at beam energies $E = 400 -1500$ MeV/nucleon. This analysis utilizes a Gaussian process (GP) emulator applied to the isospin-dependent quantum molecular dynamics (IQMD) model for heavy-ion collisions, both with and without incorporating the momentum dependence of the single-nucleon potentials. Specifically, at the 68% confidence level, using rapidity and transverse velocity dependence of proton elliptic flow data with and without consideration of the momentum dependence, the inferred incompressibility values are $K=188.9^{+2.9}_{-4.5}$ MeV and $256.1^{+8.2}_{-8.7}$ MeV at $E = 400$ MeV/nucleon, respectively. When the transverse momentum dependence of proton-like directed flow data is included, the inferred incompressibility values become $K=222.3^{+9.0}_{-9.9}$ MeV and $K=285.5^{+6.7}_{-7.3}$ MeV, respectively. Furthermore, we found that the value of K derived from observables of proton elliptic flow increases with beam energy. Finally, this indicates that the equation of state (EoS) of nuclear matter hardens at higher densities and temperatures in reactions with higher beam energies.

Bayesian inference↗
DOE OSTI2023

Do Minor Interactions Trigger Star Formation in Galaxy Pairs?

Abstract We analyze the galaxy pairs in a set of volume limited samples from the Sloan Digital Sky Survey to study the effects of minor interactions on the star formation rate (SFR) and color of galaxies. We carefully design control samples of isolated galaxies by matching the stellar mass and redshift of the minor pairs. The SFR distributions and color distributions in the minor pairs differ from their controls at >99% significance level. We also simultaneously match the control galaxies in stellar mass, redshift and local density to assess the role of the environment. The null hypothesis can be rejected at >99% confidence level even after matching the environment. Our analysis shows a quenching in the minor pairs where the degree of quenching decreases with the increasing pair separation and plateaus beyond 50 kpc. We also prepare a sample of minor pairs with H α line information. We calculate the SFR of these galaxies using the H α line and repeat our analysis. We observe a quenching in the H α sample too. We find that the majority of the minor pairs are quiescent systems that could be quenched due to minor interactions. Combining data from the Galaxy Zoo and Galaxy Zoo 2, we find that only ∼1% galaxies have a dominant bulge, 4%–7% galaxies host a bar and 5%–10% of galaxies show active galactic nucleus (AGN) activity in minor pairs. This indicates that the presence of bulge, bar or AGN activity plays an insignificant role in quenching the galaxies in minor pairs. The more massive companion satisfies the criteria for mass quenching in most of the minor pairs. We propose that the stripping and starvation likely caused the quenching in the less massive companion at a later stage of evolution.

Astronomy & Astrophysics↗
DOE OSTI2020

Predicting the rotation profile in ITER

Determining the toroidal rotation for future tokamaks like ITER is a challenging and important problem. By combining empirical scalings for the intrinsic rotation at the top of the pedestal with the expected neutral beam torque and modeling of momentum transport, the toroidal rotation profile for ITER is predicted with TGYRO using TGLF (SAT0 and SAT1). On axis rotation exceeds 20 krad s –1 and the E x B shear is significant enough to reduce turbulent transport and significantly increase confinement and fusion power when comparing to cases that ignore the effect of rotation. Here, the prediction of the rotation at the top of the pedestal is made with increased confidence due to experiments and modeling in DIII-D that have determined the importance of fast-ion and neutral particle transport effects on intrinsic rotation at this location. In particular, the effect of neutral particles on momentum transport in the pedestal region is found to be insignificant.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2020

Investigation of the neoclassical ambipolar electric field in ion-root plasmas on W7-X

The role of the radial electric field in high-performance ion-root plasmas on Wendelstein 7-X (W7-X) is examined and compared with neoclassical predictions herein. The W7-X stellarator is the world’s first large-scale optimized stellarator. One of the important targets chosen for optimization during the W7-X design process was the reduction of core neoclassical heat transport. This optimization was targeted for reactor-relevant high-density plasmas with $T_e ≈ T_i$ in which the neoclassical ambipolar radial electric field is expected to be negative throughout the plasmas core. Measurements of the core radial electric field $(E_r)$ have confirmed that ion-root conditions (negative $(E_r)$ in the plasma core) have been achieved in W7-X with high-density plasmas and central ECRH. These measured $(E_r)$ profiles agree well with the neoclassical ambipolar $(E_r)$ predicted by the code SFINCS . This good agreement provides confidence in the validity of neoclassical calculations in high-density ion-root conditions, and enables initial studies on the role of neoclassical transport in the optimized high-density regime of W7-X. Profile measurements of electron temperature $(T_e)$, ion temperature $(T_i)$ and electron density $(n_e)$ along with approximations for the average value of $Z$ eff have been used as inputs to the sfincs code to calculate the ambipolar $E_r$ profile along with neoclassical ion and electron energy flux profiles $(Q$ NCi , $Q$ NCe $)$. Finally the total experimental energy input to the plasma from ECRH heating has been compared to the neoclassical energy fluxes to provide a first estimate for the fraction of transport that can be attributed to neoclassical processes in reactorrelevant high-density ion-root conditions.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2022

Advances in prediction of tokamak experiments with theory-based models

The successful validation of theory-based models of transport, MHD stability, heating and current drive, with tokamak measurements over the last 20 years, has laid the foundation for a new era where these models can be routinely used in a "predict first" approach to design and predict the outcomes of experiments on tokamaks today. The capability to predict the plasma confinement and core profiles with a quantified uncertainty, based on a multi-machine, international, database of experience, will provide confidence that a proposed discharge will remain within the operational limits of the tokamak. Developing this predictive capability for the first generation of burning plasma devices, beginning with ITER, and progressing to tokamak demonstration reactors, is a critical mission of fusion energy research. Major advances have been made implementing this predict first methodology on today's tokamaks. In this work, an overview of several of these recent advances will be presented, providing the integrated modeling foundations of the experimental successes. The first steps to include boundary plasmas, and tokamak control systems, have been made. A commitment to predicting experiments as part of the planning process is needed in order to collect predictive accuracy data and evolve the models and software into a robust whole discharge pulse design simulator.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2021

Integrated model predictions on the impact of substrate damage on gas dynamics during ITER burning-plasma operations

Divertor design and choice of plasma-facing materials (PFM) will be essential to the success of next-generation fusion reactors as they operate under more powerful scenarios. Understanding and controlling interactions between the plasma and PFM is essential to making these choices. Within these plasma–material interactions and especially in tungsten (W), the interplay between the most abundant plasma species (hydrogen isotopes and helium, He) with the wall material alters fuel retention. However, this interplay is yet to be sufficiently understood to confidently project fuel retention levels to future fusion devices. The paper presents a series of integrated simulations of fusion plasmas and their interaction with tungsten. Specifically, this study assesses the impact of He plasma pre-exposure on hydrogenic species retention during 100 s of burning plasma operations (BPO) in ITER. Multiple pre-exposure scenarios are considered, including sub-surface damage resulting from exposures in the linear device PISCES and from early ITER He-operation. The predictions from these consecutive He-BPO exposures show that fuel content and spatial distribution in the material are largely determined by the He-induced damage, as manifest in: (i) changes in surface temperature expected during BPO have little effect on fuel retention in the presence of He-induced damage; (ii) gas content stabilizes quickly in substrates pre-exposed in PISCES, at levels set by the concentration of pre-existing vacancies, while it continues to increase in substrates initially pristine or pre-exposed to ITER He plasmas; (iii) the presence of He and He–V clusters in the near-surface region locally increases hydrogenic retention, but decreases its permeation; this results in hydrogenic species that remain closer to the surface in pre-damaged substrates, while the bulk content is higher for initially pristine cases. In summary, the interaction and binding of D and T with the pre-existing He–V clusters modifies retention and permeation of hydrogen species during ITER BPO.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2022

Simultaneous measurements of unstable and stable Alfvén eigenmodes in JET

Here, we report the novel experimental observation of both unstable and stable toroidicity-induced Alfvén eigenmodes (TAEs) measured simultaneously in a JET tokamak plasma. The three-ion-heating scheme (D-DNBI-3He) is employed to accelerate deuterons to MeV energies, thereby destabilizing TAEs with toroidal mode numbers n = 3–5, each decreasing in mode amplitude. At the same time, the Alfvén eigenmode active diagnostic resonantly excites a stable n = 6 TAE with total normalized damping rate –γ/ω 0 ≈ 1%–4%. Hybrid kinetic-MHD modeling with codes NOVA-K and MEGA both find eigenmodes with similar frequencies, mode structures, and radial locations as in experiment. NOVA-K demonstrates good agreement with the n = 3, 4, and 6 TAEs, matching the damping rate of the n = 6 mode within uncertainties and identifying radiative damping as the dominant contribution. Improved agreement is found with MEGA for all modes: the unstable n = 3–5 and stable n = 2, 6 modes, with the latter two stabilized by higher intrinsic damping and lower fast ion drive, respectively. While some discrepancies remain to be resolved, this unique validation effort gives us confidence in TAE stability predictions for future fusion devices.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2024

NSTX-U research advancing the physics of spherical tokamaks

Abstract The objectives of NSTX-U research are to reinforce the advantages of STs while addressing the challenges. To extend confinement physics of low- A , high beta plasmas to lower collisionality levels, understanding of the transport mechanisms that set confinement performance and pedestal profiles is being advanced through gyrokinetic simulations, reduced model development, and comparison to NSTX experiment, as well as improved simulation of RF heating. To develop stable non-inductive scenarios needed for steady-state operation, various performance-limiting modes of instability were studied, including MHD, tearing modes, and energetic particle instabilities. Predictive tools were developed, covering disruptions, runaway electrons, equilibrium reconstruction, and control tools. To develop power and particle handling techniques to optimize plasma exhaust in high performance scenarios, innovative lithium-based solutions are being developed to handle the very high heat flux levels that the increased heating power and compact geometry of NSTX-U will produce, and will be seen in future STs. Predictive capabilities accounting for plasma phenomena, like edge harmonic oscillations, ELMs, and blobs, are being tested and improved. In these ways, NSTX-U researchers are advancing the physics understanding of ST plasmas to maximize the benefit that will be gained from further NSTX-U experiments and to increase confidence in projections to future devices.

74 ATOMIC AND MOLECULAR PHYSICS↗
DOE OSTI2024

Transport and stability in sustained high q min , high β N discharges on DIII-D

Abstract To address the needs for a fusion pilot plan design, DIII-D/EAST joint experiments on DIII-D have demonstrated high normalized beta β N ∼ 4.2, toroidal beta β T ∼ 3.3% with q min > 2, q 95 ⩽ 8 sustained for more than six energy confinement times in high poloidal beta regime. The excellent energy confinement quality ( H 98y2 ∼ 1.8) is achieved with an internal transport barrier at high line-averaged Greenwald density fraction f Gr > 0.9. The trapped gyro-Landau fluid (TGLF) modeling of the transport characteristics shows that the beam-driven rotation does not play an important role in the high confinement quality. The modeling also captures very well several transport features, giving us confidence in using integrated modeling to project these experimental results to future machines. The high-performance phase is terminated by fast-growing modes triggered near the n = 1 ideal-wall kink stability limit. New radio frequency (RF) capabilities for off-axis current drive could remove the residual ohmic current to achieve a fully non-inductive state, and improve the mode–wall coupling to increase the ideal-wall β N limit, enabling sustainment of the fully non-inductive high performance plasma in stationary conditions.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2024

Comparison of reduced model predictions for divertor detachment onset and reattachment timescales in ASDEX Upgrade and JET experiments

Building on prior analysis of ASDEX Upgrade (AUG) experiments (Henderson et al 2023 Nucl. Fusion63 086024), this study compares simple analytical formula predictions for divertor detachment onset and reattachment timescales in JET experiments. Detachment onset primarily scales with divertor neutral pressure, impurity concentration, power directed to the targets, machine size, and integral perpendicular power decay length. JET experiments, focusing on seeding mixtures of Ne and Ar, align with the detachment onset predictions. Radiation efficiencies among the impurities show good agreement with the model predictions, contrasting with AUG observations which suggested higher efficiency for Ar and lower efficiency for Ne. The time taken to re-ionise the neutral volume in front of the outer target in fully detached divertor conditions was measured following both abrupt increases in injected neutral beam power and, separately, cutting of the impurity gas flow. Re-ionisation of the neutrals occurs within approximately 1 s on JET, which aligns with the simple model prediction derived from AUG data. While the AUG results are not new, their comparison with the JET results enhances understanding, reinforcing confidence in using simple models to predict future reactor scenarios.

JET↗
DOE OSTI2024

Modelling and experiment to stabilize disruptive tearing modes in the ITER baseline scenario in DIII-D

Abstract The achievement of high gain, stationary conditions in a tokamak scenario aimed at producing fusion energy in the ITER Project is crucial to the demonstration that this form of energy can be used in future reactors to provide cheap and clean energy globally. Disruptions are a challenge for the fusion energy field, in particular for the ‘ITER Baseline Scenario’ (IBS), as reproduced in the DIII-D tokamak. This work shows that a solution has been found for the m = 2/ n = 1 tearing modes that have consistently caused disruptions in the IBS: stable operation down to zero input torque was achieved by modifying the current density profile at the beginning of the pressure flattop and the ELM character later in the discharges, guided by previous results showing that the most likely cause of these instabilities is the current density profile. The coupling between sawteeth, n>2 modes and the 2/1 TMs is shown to not be statistically significant, nor the leading origin for the evolution towards instability. Ideal and resistive MHD modeling provide positive verification that a steeper ‘well’ in the region of the q = 2 rational surface leads to worse ideal stability, higher tearing index Δ’ and lower threshold Δ’ c for resistive instabilities, consistent with the experimental results. This provides confidence that the methods used in this work can be extrapolated to other devices and applied to avoid disruptions in ITER and pulsed fusion devices worldwide.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2024

High performance power handling in the absence of an H-mode edge in negative triangularity DIII-D plasmas

Abstract Experiments performed during strongly-shaped high-power diverted negative triangularity (NT) experiments in DIII-D achieved detached divertor conditions and a transient-free edge, showcasing the potential for application of NT to a core-edge integrated reactor-like scenario and providing the first characterization of the parametric dependencies for detachment onset. Detached divertor conditions will be required in future devices to mitigate divertor heat fluxes. Access to dissipative divertor conditions was investigated via an increase in upstream density. Detachment onset at the outer strike point was achieved with H-mode level confinement H 98 − y 2 ∼ 1 and reactor-relevant normalized pressures β N ∼ 2 . Confinement degradation was observed with deeper detachment, associated with the loss of an electron temperature pedestal. Differences in geometry, radial transport, impact of cross field drifts are discussed to explain differences in access to detachment in NT discharges. Higher normalized densities, with respect to equivalent discharges in positive triangularity, were necessary to achieve detachment, partially explained by the shorter parallel connection length to the targets. The effect of cross-field particle drifts ( E × B , B × ∇ B ) on access to detachment was demonstrated by the lower upstream density needed to access detachment with ion B × ∇ B drift directed outside of the active divertor (Greenwald fraction f Gw ∼ 0.9–1.0 vs f Gw ∼ 1.3). The upstream density at detachment onset was observed to increase linearly with plasma current with ion B × ∇ B drift into the divertor, consistent with the observed narrowing of the scrape-off layer heat flux width λ q . Edge fluid simulations capture separatrix densities needed to achieve detachment in NT plasma and their dependence on drift direction. The ability to reproduce detachment dynamics in NT plasma increases the confidence in future design studies for NT divertors.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗