N. Bertelli
A5031563058- Magnetic confinement fusion research
- Particle accelerators and beam dynamics
- Ionosphere and magnetosphere dynamics
- Superconducting Materials and Applications
- Plasma Diagnostics and Applications
- Laser-Plasma Interactions and Diagnostics
- Fusion materials and technologies
- Gyrotron and Vacuum Electronics Research
- Nuclear reactor physics and engineering
- Engineering Applied Research
- Solar and Space Plasma Dynamics
- Metallurgical Processes and Thermodynamics
- Particle Accelerators and Free-Electron Lasers
- Geomagnetism and Paleomagnetism Studies
- Antenna Design and Analysis
- Acoustic Wave Resonator Technologies
- Atomic and Subatomic Physics Research
- Physics of Superconductivity and Magnetism
- Electrostatic Discharge in Electronics
- Electromagnetic Launch and Propulsion Technology
- Dust and Plasma Wave Phenomena
- Laser-induced spectroscopy and plasma
- Semiconductor materials and devices
- Space Exploration and Technology
- Probabilistic and Robust Engineering Design
Princeton Plasma Physics Laboratory
2016-2025
Princeton University
2014-2025
Massachusetts Institute of Technology
2015-2021
Fusion Academy
2015-2021
Fusion (United States)
2015-2021
Royal Military Academy
2021
The University of Texas at Austin
2015
Plasma Technology (United States)
2015
Lomonosov Moscow State University
2012
Institute for Atomic and Molecular Physics
2008-2011
Abstract The objectives of NSTX-U research are to reinforce the advantages STs while addressing challenges. To extend confinement physics low- A , high beta plasmas lower collisionality levels, understanding transport mechanisms that set performance and pedestal profiles is being advanced through gyrokinetic simulations, reduced model development, comparison NSTX experiment, as well improved simulation RF heating. develop stable non-inductive scenarios needed for steady-state operation,...
Abstract WEST is an MA class superconducting, actively cooled, full tungsten (W) tokamak, designed to operate in long pulses up 1000 s. In support of ITER operation and DEMO conceptual activities, key missions are: (i) qualification high heat flux plasma-facing components integrating both technological physics aspects relevant particle exhaust conditions, particularly for the monoblocks foreseen divertor; (ii) integrated steady-state at confinement, with a focus on power issues. During phase...
Abstract ST40 is a compact, high-field ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi>B</mml:mi> <mml:mi mathvariant="normal">T</mml:mi> <mml:mn>0</mml:mn> </mml:mrow> </mml:msub> <mml:mtext>⩽</mml:mtext> <mml:mn>2.1</mml:mn> <mml:mstyle scriptlevel="0"/> <mml:mtext>T</mml:mtext> </mml:math> ) spherical tokamak (ST) with mission to expand the physics and technology basis for ST route commercial fusion. The research programme covers...
Abstract We explore the characteristics of EMIC waves generated in a non‐dipole, compressed magnetic field at minimum field. conducted 2D full‐wave simulations using Petra‐M code, focusing on outer dayside magnetosphere for range L values . By comparing simulation results with MMS observations, we aim to understand how observed wave are affected by shifting source region across different L‐shells. Our findings indicate that direction Poynting vector systematically changes depending local...
The National Spherical Torus Experiment (NSTX) has undergone a major upgrade, and the NSTX Upgrade (NSTX-U) Project was completed in summer of 2015.NSTX-U first plasma subsequently achieved, diagnostic control systems have been commissioned, H-mode accessed, magnetic error fields identified mitigated, physics research campaign carried out.During ten run weeks operation, NSTX-U surpassed record pulse-durations toroidal (TF), high-performance ~1 MA plasmas comparable to best sustained near...
Abstract For successfully heating plasma with waves in the Ion Cyclotron Range of Frequencies (ICRF), mitigating impurity production is just as crucial maximizing power coupling, especially high-Z environments [Urbanczyk 2021]. Only when coupled limited influence on production, can ICRF truly become a powerful tool to directly deposit energy ions, modify turbulence-driven transport and enhance efficiency fusion reactions. &#xD;To do so, one must rely toroidal array at least three active...
Full wave simulations of fusion plasmas show a direct correlation between the location fast-wave cut-off, radiofrequency (RF) field amplitude in scrape-off layer (SOL) and RF power losses SOL observed National Spherical Torus eXperiment (NSTX). In particular, increase significantly when launched waves transition from evanescent to propagating that region. Subsequently, large electric occurs SOL, driving proxy collisional loss term is added. A 3D reconstruction absorbed presented showing...
Scattering effects induced by edge density fluctuations on lower hybrid (LH) wave propagation are investigated. The scattering model used here is based the work of Bonoli and Ott (1982 Phys. Fluids 25 361). It utilizes an electromagnetic kinetic equation solved a Monte Carlo technique. This has been implemented in GENRAY, ray-tracing code which explicitly simulates propagation, as well collisionless collisional damping processes, over entire plasma discharge, including scrape-off layer that...
A heuristic criterion for the full suppression of an NTM was formulated as η ≡ j CD,max / BS ⩾ 1.2 (Zohm et al 2005 J. Phys. Conf. Ser. 25 234), where is maximum in driven current density profile applied to stabilize mode and local bootstrap density. In this work we subject a systematic theoretical analysis on basis generalized Rutherford equation. Taking into account only effect CD inside island, new by minimum total obtained form allowed value width current, w dep , combined with required...
Helicon waves have been recently proposed as an off-axis current drive actuator for DIII-D, FNSF, and DEMO tokamaks. Previous ray tracing modeling using GENRAY predicts strong single pass absorption in the mid-radius region on DIII-D high beta tokamak discharges. The full wave code AORSA, which is valid to all order of Larmor radius can resolve arbitrary ion cyclotron harmonics, has used validate technique. If scrape-off-layer (SOL) ignored modeling, AORSA agrees with both amplitude location...
Abstract This paper reports a new numerical scheme to simulate the radio-frequency (RF) induced RF sheath, which is suitable for large 3D simulation. In sheath boundary model, tangential component of electric field ( <?CDATA $E_\mathrm{t}$?> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:msub> <mml:mi>E</mml:mi> <mml:mrow> <mml:mi mathvariant="normal">t</mml:mi> </mml:mrow> </mml:msub> </mml:math> ) given by gradient scalar potential. We introduce two...
Time-dependent simulations are used to evolve plasma discharges in combination with a modified Rutherford equation for calculation of neoclassical tearing mode (NTM) stability response electron cyclotron (EC) feedback control ITER. The main application this integrated approach is support the development algorithms by analyzing physics-based models and assess how uncertainties detection magnetic island EC alignment affect ability ITER system fulfill its purpose. Simulations indicate that it...
Three identical new WEST Ion Cyclotron Resonance Heating (ICRH) antennas have been designed, assembled then commissioned on plasma from 2013 to 2019.The ICRH system is both load-resilient and compatible with long-pulse operations.The three successfully operated together in 2019 2020.The load resilience capability has demonstrated the antenna feedback controls for phase matching developed.The breakdown detection systems validated protected antennas.The use of combination Lower Hybrid...
The plasma current is ramped up primarily by a 28 GHz electron cyclotron wave (ECW) in the Q-shu University experiment Steady-State Spherical Tokamak (QUEST), with multiple harmonic resonance layers from second to fourth stay core. A steering antenna comprising two quasi-optical mirrors enhances power density of ECWs. ECW beam injected obliquely low-field side where parallel refractive index N∥ = 0.75 at second-harmonic layer. Analysis condition has found that energetic electrons moving...
Abstract DIII-D physics research addresses critical challenges for the operation of ITER and next generation fusion energy devices. This is done through a focus on innovations to provide solutions high performance long pulse operation, coupled with fundamental plasma understanding model validation, drive scenario development by integrating core boundary plasmas. Substantial increases in off-axis current efficiency from an innovative top launch system EC power, pressure broadening Alfven...
Abstract This paper reports the significant advancement of our ability to model and understand how RF waves interact with SOL plasma, by developing for full torus 3D scrape-off layer (SOL) plasma simulation together antenna core in NSTX-U device HHFW frequency regime a cold model. The present extends previous modeling (Bertelli et al 2020 AIP Conf. Proc. 2254 030001) geometry including realistic order capture more experimental situation fully wave field effects interaction and, at same time,...
Abstract Several experiments on different machines and in fast wave (FW) heating regimes, such as hydrogen minority high harmonic waves (HHFW), have found strong interaction between radio-frequency (RF) the scrape-off layer (SOL) region. This paper examines propagation power loss SOL by using full code AORSA, which edge plasma beyond last closed flux surface (LCFS) is included solution domain a collisional damping parameter used proxy to represent real, most likely nonlinear, processes. 2D...
The National Spherical Torus Experiment (NSTX) is currently being upgraded to operate at twice the toroidal field and plasma current (up 1 T 2 MA), with a second, more tangentially aimed neutral beam (NB) for rotation control, allowing pulse lengths up 5 s. Recent NSTX physics analyses have addressed topics that will allow NSTX-Upgrade achieve research goals critical Fusion Nuclear Science Facility. These include producing stable, 100% non-inductive operation in high-performance plasmas,...
Abstract The mission of WEST (tungsten-W Environment in Steady-state Tokamak) is to explore long pulse operation a full tungsten (W) environment for preparing next-step fusion devices (ITER and DEMO) with focus on testing the ITER actively cooled W divertor tokamak conditions. Following successful completion phase 1 (2016-2021), 2 started December 2022 lower made entirely ITER-grade mono-blocks. A boronization prior first plasma attempt allowed smooth startup new divertor. Despite reduced...
Helicon waves are thought to be promising in various tokamaks, such as DIII-D, because they can penetrate reactor-grade high-density cores and drive the off-axis current with higher efficiency. In frequency regime ∼ 476 MHz, both slow electrostatic fast electromagnetic helicon coexist DIII-D. If antenna parasitically excites mode, these propagate along magnetic field line into scrape-off layer (SOL). Although importance of misalignment Faraday screen electron density SOL on excitation...
At the power levels required for significant heating and current drive in magnetically-confined toroidal plasma, modification of particle distribution function from a Maxwellian shape is likely (Stix 1975 Nucl. Fusion 15 737), with consequent changes wave propagation location amount absorption. In order to study these effects computationally, both finite-Larmor-radius high-harmonic fast (HHFW), versions full-wave, hot-plasma simulation code TORIC (Brambilla 1999 Plasma Phys. Control. 41 1...
Although lower hybrid waves are effective at driving currents in present-day tokamaks, they expected to interact strongly with high-energy particles extrapolating reactors. In the presence of a radial alpha particle birth gradient, this interaction can take form wave amplification rather than damping. While it is known that more easily occurs when launching from tokamak high-field side, extent has not been made quantitative. Here, by tracing rays launched high-field-side tokamak, required...
Waves in the ion-cyclotron range of frequencies (ICRF) used for tokamak heating are known to interact strongly with scrape-off layer (SOL) plasma, potentially limiting ICRF performance. We present effect on triple-probe signals Experimental Advanced Superconducting Tokamak (EAST) experiment, an advanced superconducting two antennas and 12 MW source power support high-power long-pulse operation. Applying time-resolved magnetic mapping divertor probe arrays enables detailed sensing spatial...
Abstract The mission of the low aspect ratio spherical tokamak NSTX-U is to advance physics basis and technical solutions required for optimizing configuration next-step steady-state fusion devices. will ultimately operate at up 2 MA plasma current 1 T toroidal field on axis 5 s, has available 15 MW neutral beam injection power different tangency radii 6 high harmonic fast wave heating. With these capabilities develop understanding control tools ramp-up sustain performance fully...