@article{davda_laggner_kallenberg_ammons_crowley_scoville_hossain_lietz_shannon_mazzeo_et al._2025, title={AMAROK: A Novel Single-Turn Multi-Coil Antenna Demonstration Setup for DIII-D Neutral Beam Injector Upgrade}, DOI={10.1109/ppps56198.2025.11248474}, abstractNote={The Advanced Multi-turn Adaptive Radio-Frequency (RF) source on Kinetic Neutrals (AMAROK) is a novel full-scale RF-Inductively Coupled Plasma (ICP) source producing positive ions designed to upgrade and enhance the heating power of the DIII-D Neutral Beam Injection (NBI) system. AMAROK features a racetrack-shaped dielectric tube measuring 40 cm in length, with a turn diameter of 28 cm at the curved ends, and a height of 30 cm. It is designed to operate with deuterium at a flow rate of 15 Torr-L/s to match the conditions in the NBI injector at the DIII-D, with an operating pressure ranging from 0.1 to 10 Pa. This configuration aims to create a homogeneous plasma source across a potential extraction area of 48 cm by 12 cm. A water-cooled racetrack-shaped Faraday shield was designed to minimize the erosion of the dielectric window, and commercially available solid-state RF generators provide up to 200 kW of power. The optimal frequency for efficient power coupling is currently being explored between <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$2-4 \text{MHz}$</tex>, with the goal of achieving an ion density of approximately <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$10^{18} \mathrm{m}^{-3}$</tex> that is needed to sustain the required ion density to extract a 85 A positive ion beam. AMAROK is expected to explore innovations in single-turn multi-coil antennas, dubbed as the wolverine coil, to study the neutral dynamics within the source for better extraction of the neutrals. AMAROK will also investigate interactions of neutrals with Faraday shields, power coupling, density uniformity, and RF frequency sweeps.}, author={Davda, K. M. and Laggner, F. M. and Kallenberg, E. and Ammons, K. J. and Crowley, B. J. and Scoville, J. T. and Hossain, M.S. and Lietz, A. M. and Shannon, S. C. and Mazzeo, A. G. and et al.}, year={2025}, month={Jun} }
 @article{mazzeo_laggner_ammons_hossain_kallenberg_king_davda_shah_shannon_lietz_et al._2025, title={Design and Engineering of LUPIN: A Test-Bed Radio-Frequency Ion Source for Enhanced Neutral Beam Injection on DIII-D}, volume={6}, url={https://doi.org/10.1080/15361055.2025.2498216}, DOI={10.1080/15361055.2025.2498216}, journal={Fusion Science & Technology}, author={Mazzeo, Arthur and Laggner, Florian M. and Ammons, Keanu J. and Hossain, Sazzad and Kallenberg, Evan and King, Liam and Davda, Kirtan and Shah, Miral and Shannon, Steven C. and Lietz, Amanda M. and et al.}, year={2025}, month={Jun} }
 @article{kallenberg_crowley_scoville_laggner_mazzeo_ammons_hossain_king_lietz_shannon_2025, title={Design and Study of Inductively Coupled Plasma Chamber Components Using the SupRISE Test Device at DIII-D}, volume={8}, url={https://doi.org/10.1080/15361055.2025.2515323}, DOI={10.1080/15361055.2025.2515323}, journal={Fusion Science & Technology}, author={Kallenberg, Evan and Crowley, Brendan and Scoville, John T. and Laggner, Florian M. and Mazzeo, Arthur and Ammons, Keanu J. and Hossain, Md. Sazzad and King, Liam and Lietz, Amanda M. and Shannon, Steven C.}, year={2025}, month={Aug} }
 @article{hossain_regev_mazzeo_ammons_laggner_shah_davda_shannon_kallenberg_scoville_et al._2025, title={Production- and Transport-Limited Fluxes in Inductively Coupled Ion Sources for Neutral Beam Injectors}, DOI={10.1109/ppps56198.2025.11248336}, abstractNote={Neutral beam injection (NBI) is the most powerful heating system at the DIII-D National Fusion Facility, using 8 injectors that deliver up to 20 MW of combined power. To enhance NBI performance, development efforts focus on optimizing radio-frequency (RF) inductively coupled plasma (ICP) positive ion sources to achieve high-density positive hydrogen ion beams. In RF ICP sources, this optimization involves balancing ion production and transport mechanisms. In a production-limited regime, ion flux is primarily constrained by ionization and dissociation rates; increasing RF power or improving electron heating directly enhances ion flux. Conversely, in a transport-limited regime, the efficiency of transport mechanisms, such as diffusion and convection, restricts ion flux. While increasing RF power still contributes to additional ion production, the transport bottleneck limits how much of that production translates into higher flux. Understanding the transition between these regimes is crucial for optimization.}, author={Hossain, M.S. and Regev, T. and Mazzeo, A. and Ammons, K. J. and Laggner, F. M. and Shah, M. A. and Davda, K. M. and Shannon, S. C. and Kallenberg, E. and Scoville, J. T. and et al.}, year={2025}, month={Jun} }