2021
1.
Lazerson, Samuel A.; Pfefferlé, David; Drevlak, Michael; Smith, Håkan; Geiger, Joachim; Äkäslompolo, Simppa; Xanthopoulos, Pavlos; Dinklage, Andreas; Ford, Oliver; McNeely, Paul; Rust, Norbert; Bozhenkov, Sergey; Hartmann, Dirk; Rahbarnia, Kian; Andreeva, Tamara; Schilling, Jonathan; Brandt, Christian; Neuner, Ulrich; Thomsen, Henning; Wolf, Robert C.; Team, The W7-X.
Modeling and Measurement of Energetic Particle Slowing down in Wendelstein 7-X Journal Article
In: vol. 61, no. 9, pp. 096005, 2021, ISSN: 0029-5515.
Abstract | Links | BibTeX | Tags: benchmark, fast particles, numerical method, slowing-down distribution, stellarator, VENUS-LEVISLEVIS
@article{lazersonModelingMeasurementEnergetic2021,
title = {Modeling and Measurement of Energetic Particle Slowing down in Wendelstein 7-X},
author = {Samuel A. Lazerson and David Pfefferl\'{e} and Michael Drevlak and Hr{a}kan Smith and Joachim Geiger and Simppa \"{A}k\"{a}slompolo and Pavlos Xanthopoulos and Andreas Dinklage and Oliver Ford and Paul McNeely and Norbert Rust and Sergey Bozhenkov and Dirk Hartmann and Kian Rahbarnia and Tamara Andreeva and Jonathan Schilling and Christian Brandt and Ulrich Neuner and Henning Thomsen and Robert C. Wolf and The W7-X. Team},
doi = {10.1088/1741-4326/ac0771},
issn = {0029-5515},
year = {2021},
date = {2021-07-01},
urldate = {2021-07-01},
volume = {61},
number = {9},
pages = {096005},
publisher = {IOP Publishing},
abstract = {The energetic particle slowing down model in the BEAMS3D stellarator neutral beam code is compared to analytic models and experimental data from the Wendelstein 7-X experiment (W7-X). Recently, the first neutral beam experiments were performed in W7-X, providing validation of neutral beam deposition codes (Lazerson S.A. et al 2020 Nucl. Fusion 60 076020). This work builds upon that work, and follows the gyro-center orbits of the neutral-beam-generated fast ions to the plasma boundary. Slowing down times based on measurements of diamagnetic energy changes are compared to simulation data. A discharge solely heated by neutral beam injection is used to compare neoclassical heat flux estimates to neutral beam fueling, heating, and current drive. Experimental estimates of electron heat diffusivity suggest that electron turbulence is destabilized by density peaking in the discharge. Neutral beam current drive dominates over bootstrap current, resulting in a reversal of the toroidal current, as seen experimentally. Particle losses and heat flux through the equilibrium boundary are described. The effects of the magnetic configuration and plasma density on such parameters are also assessed. Benchmarking based on analytic estimates and other energetic particle codes is presented.},
keywords = {benchmark, fast particles, numerical method, slowing-down distribution, stellarator, VENUS-LEVISLEVIS},
pubstate = {published},
tppubtype = {article}
}
The energetic particle slowing down model in the BEAMS3D stellarator neutral beam code is compared to analytic models and experimental data from the Wendelstein 7-X experiment (W7-X). Recently, the first neutral beam experiments were performed in W7-X, providing validation of neutral beam deposition codes (Lazerson S.A. et al 2020 Nucl. Fusion 60 076020). This work builds upon that work, and follows the gyro-center orbits of the neutral-beam-generated fast ions to the plasma boundary. Slowing down times based on measurements of diamagnetic energy changes are compared to simulation data. A discharge solely heated by neutral beam injection is used to compare neoclassical heat flux estimates to neutral beam fueling, heating, and current drive. Experimental estimates of electron heat diffusivity suggest that electron turbulence is destabilized by density peaking in the discharge. Neutral beam current drive dominates over bootstrap current, resulting in a reversal of the toroidal current, as seen experimentally. Particle losses and heat flux through the equilibrium boundary are described. The effects of the magnetic configuration and plasma density on such parameters are also assessed. Benchmarking based on analytic estimates and other energetic particle codes is presented.