Article
Instruments & Instrumentation
Jie Chen, David Brower, Weixing Ding, Ryota Yoneda, Daniel Finkenthal
Summary: A correlation polarimeter-interferometer system was developed to detect small amplitude magnetic and density fluctuations in the DIII-D tokamak. By utilizing collinear, frequency-offset, orthogonally polarized electromagnetic waves, the system is able to achieve lower noise floor compared to standard measurements and observe broadband magnetic and density fluctuations in H-mode plasmas.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Instruments & Instrumentation
S. Munaretto, C. E. Myers, S. P. Gerhardt, N. C. Logan, J. E. Menard, E. J. Strait
Summary: A time domain algorithm has been developed to remove vacuum pickup from magnetic diagnostic signals in tokamaks. The algorithm reduces the noise level and improves the detection accuracy of plasma perturbations.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2022)
Article
Physics, Fluids & Plasmas
Feng Cai, Mark Smith, William Blanchard, Dang Cai, Jamie Hennessy, Han Zhang, Douglas Loesser
Summary: The vacuum seal design of the NSTX-U machine core has been upgraded to enhance vacuum seals and lower gas permeation. The use of double elastomeric seals and pumped interspaces has significantly reduced the overall pressure difference and leakage rates.
IEEE TRANSACTIONS ON PLASMA SCIENCE
(2022)
Article
Physics, Fluids & Plasmas
L. Simons, C. Cowley, P. Fuller, I Bykov, D. Rudakov, Y. Andrew, M. Coppins
Summary: Comprehensive upgrades to the dust transport code DTOKS have enhanced the simulation of plasma-dust interaction in TOKamaks, providing insight into dust dynamics and lifetimes. The simulations showed that graphite dust particles rapidly ablate near the outer divertor strike point, creating a source of neutral carbon atoms, with results approximately matching experimental observations after corrections. Coupling DTOKS-U results with visualization software offers a powerful tool for validating simulations and predicting dust behavior.
PLASMA PHYSICS AND CONTROLLED FUSION
(2021)
Article
Instruments & Instrumentation
Yapeng Zhang, Zhengdong Liu, Chunqing Xing, Wei Sun, Jiayong Zhong
Summary: This paper presents the development of a new optical polarimeter based on the Martin-Puplett interferometer (MPI), which can probe magnetic fields using the Faraday rotation method. The design and working principle of the MPI polarimeter are introduced. Laboratory tests demonstrate its measurement capabilities and comparison with a Gauss meter validates its accuracy, indicating potential for magnetic field measurement applications.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2023)
Article
Geochemistry & Geophysics
Sharmila Padmanabhan, Todd C. Gaier, Alan B. Tanner, Shannon T. Brown, Boon H. Lim, Steven C. Reising, Robert Stachnik, Rudi Bendig, Richard Cofield
Summary: The TEMPEST-D instrument is a five-frequency millimeter-wave radiometer operating from 87 to 181 GHz, featuring a direct-detection architecture and a scanning reflector for precision end-to-end calibration. The radiometer has been operating on a 6U CubeSat in low Earth orbit since September 5, 2018, and is based on 35-nm indium phosphide (InP) high-electron-mobility transistor (HEMT) low-noise amplifiers.
IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING
(2021)
Article
Computer Science, Hardware & Architecture
Junkai Zhang, Navneet Garg, Mark Holm, Tharmalingam Ratnarajah
Summary: This article introduces a key technology for future cellular networks - full duplex millimeter-wave integrated access and backhaul networks, discussing methods to mitigate the impact of self-interference to improve spectral efficiency.
IEEE WIRELESS COMMUNICATIONS
(2021)
Article
Physics, Fluids & Plasmas
M. T. Curie, D. R. Hatch, M. Halfmoon, J. Chen, D. L. Brower, E. Hassan, M. Kotschenreuther, S. M. Mahajan, R. J. Groebner
Summary: In this study, the experimental data on electromagnetic fluctuations in DIII-D was compared with detailed gyrokinetic simulations using GENE. The unique capability of the Faraday-effect radial interferometer-polarimeter (RIP) diagnostic in measuring internal fluctuations of magnetic fields was utilized.
Article
Physics, Fluids & Plasmas
Dang Cai, Jiarong Fang, Chirag Rana, Samuel Sheckman, Peter Titus, Steve Raftopoulos
Summary: The NSTX-U upgrade project significantly improves upon the NSTX by doubling its toroidal field, plasma current, and neutral beam injection heating power, while also increasing the pulse duration. It utilizes multiple poloidal field coils to control the plasma shape and employs hard copper bus bars for power supply. The design meets the NSTX-U requirements based on electromagnetic, thermal, and structural analysis.
IEEE TRANSACTIONS ON PLASMA SCIENCE
(2022)
Article
Engineering, Electrical & Electronic
Wassim Saleh, Yoann Letestu, Ronan Sauleau, Eduardo Motta Cruz
Summary: A low-cost dual linearly polarized transmitarray antenna designed for 5G and beyond networks at D-band was presented. The antenna achieved a peak gain of 32 dBi at 150 GHz with excellent aperture efficiency. The measured radiation patterns showed good agreement with simulated results, demonstrating the robust performance of the antenna.
IEEE ANTENNAS AND WIRELESS PROPAGATION LETTERS
(2021)
Article
Physics, Fluids & Plasmas
Andrei Khodak, Douglas Loesser, Michael Messineo, Arthur Brooks, Michael Jaworski, Dennis L. Youchison, Jason Cook
Summary: The NSTX-U upgrade requires enhanced heat loads on plasma-facing components, leading to redesign of the PFCs for high heat flux regions. The HHF PFCs feature castellations and an absence of front face mounting holes to relieve thermal stresses and spread heat load. The use of isotropic graphite material and a unique locking mechanism for tile connection were key design features to ensure performance within allowable limits.
IEEE TRANSACTIONS ON PLASMA SCIENCE
(2021)
Article
Physics, Fluids & Plasmas
B. Van Compernolle, M. W. Brookman, C. P. Moeller, R. Pinsker, A. M. Garofalo, R. O'Neill, D. Geng, A. Nagy, J. P. Squire, K. Schultz, C. Pawley, D. Ponce, A. C. Torrezan, J. Lohr, B. Coriton, E. Hinson, R. Kalling, A. Marinoni, E. H. Martin, R. Nguyen, C. C. Petty, M. Porkolab, T. Raines, J. Ren, C. Rost, O. Schmitz, H. Torreblanca, H. Q. Wang, J. Watkins, K. Zeller
Summary: Helicon current drive technology, also known as fast wave CD, has been considered promising for reactor grade plasmas. A newly installed MW-level system at DIII-D aims to test this technology in reactor-relevant plasmas, with the goal of validating the physics basis.
Article
Computer Science, Information Systems
Meiyu Wang, Die Hu, Lianghua He, Jun Wu
Summary: This article proposes a deep-learning-based initial access method for mmW MIMO systems, which detects the primary synchronization signal to achieve synchronization and improves performance by using probability as the detection statistic.
IEEE WIRELESS COMMUNICATIONS LETTERS
(2022)
Article
Physics, Fluids & Plasmas
E. Belova, N. A. Crocker, J. B. Lestz, E. D. Fredrickson
Summary: Theoretical and numerical studies on sub-cyclotron frequency Alfven eigenmodes (AEs) provide insight into the observed frequency scaling with beam parameters and explain the excitation of global Alfven modes (GAEs) and compressional Alfven eigenmodes (CAEs) in various devices. These modes can be driven unstable through the Doppler shifted cyclotron resonance and can potentially be excited in ITER. Simulations and theoretical predictions demonstrate good agreement with experimental observations, indicating the potential instability of GAEs in larger aspect-ratio devices and smaller beam injection velocities.
Article
Physics, Fluids & Plasmas
W. W. Heidbrink, E. C. Hansen, M. E. Austin, G. J. Kramer, M. A. Van Zeeland
Summary: In this study, the amplitude and phase of electron cyclotron emission radiometer data from hundreds of DIII-D reversed shear Alfven eigenmodes (RSAE) and toroidicity-induced Alfven eigenmodes (TAE) are analyzed. The phase profile of the modes can remain constant or change rapidly as the mode evolves. The rapid phase changes are observed when the frequencies of an RSAE and TAE overlap and the modes couple.
Article
Physics, Fluids & Plasmas
A. Kirk, J. Adamek, R. J. Akers, S. Allan, L. Appel, F. Arese Lucini, M. Barnes, T. Barrett, N. Ben Ayed, W. Boeglin, J. Bradley, P. K. Browning, J. Brunner, P. Cahyna, S. Cardnell, M. Carr, F. Casson, M. Cecconello, C. Challis, I. T. Chapman, S. Chapman, J. Chorley, S. Conroy, N. Conway, W. A. Cooper, M. Cox, N. Crocker, B. Crowley, G. Cunningham, A. Danilov, D. Darrow, R. Dendy, D. Dickinson, W. Dorland, B. Dudson, D. Dunai, L. Easy, S. Elmore, M. Evans, T. Farley, N. Fedorczak, A. Field, G. Fishpool, I. Fitzgerald, M. Fox, S. Freethy, L. Garzotti, Y. C. Ghim, K. Gi, K. Gibson, M. Gorelenkova, W. Gracias, C. Gurl, W. Guttenfelder, C. Ham, J. Harrison, D. Harting, E. Havlickova, N. Hawkes, T. Hender, S. Henderson, E. Highcock, J. Hillesheim, B. Hnat, J. Horacek, J. Howard, D. Howell, B. Huang, K. Imada, M. Inomoto, R. Imazawa, O. Jones, K. Kadowaki, S. Kaye, D. Keeling, I. Klimek, M. Kocan, L. Kogan, M. Komm, W. Lai, J. Leddy, H. Leggate, J. Hollocombe, B. Lipschultz, S. Lisgo, Y. Q. Liu, B. Lloyd, B. Lomanowski, V. Lukin, I. Lupelli, G. Maddison, J. Madsen, J. Mailloux, R. Martin, G. McArdle, K. McClements, B. McMillan, A. Meakins, H. Meyer, C. Michael, F. Militello, J. Milnes, A. W. Morris, G. Motojima, D. Muir, G. Naylor, A. Nielsen, M. O'Brien, T. O'Gorman, M. O'Mullane, J. Olsen, J. Omotani, Y. Ono, S. Pamela, L. Pangione, F. Parra, A. Patel, W. Peebles, R. Perez, S. Pinches, L. Piron, M. Price, M. Reinke, P. Ricci, F. Riva, C. Roach, M. Romanelli, D. Ryan, S. Saarelma, A. Saveliev, R. Scannell, A. Schekochihin, S. Sharapov, R. Sharples, V. Shevchenko, K. Shinohara, S. Silburn, J. Simpson, A. Stanier, J. Storrs, H. Summers, Y. Takase, P. Tamain, H. Tanabe, H. Tanaka, K. Tani, D. Taylor, D. Thomas, N. Thomas-Davies, A. Thornton, M. Turnyanskiy, M. Valovic, R. Vann, F. Van Wyk, N. Walkden, T. Watanabe, H. Wilson, M. Wischmeier, T. Yamada, J. Young, S. Zoletnik
Article
Physics, Fluids & Plasmas
N. A. Crocker, S. Kubota, W. A. Peebles, T. L. Rhodes, E. D. Fredrickson, E. Belova, A. Diallo, B. P. LeBlanc, S. A. Sabbagh
Article
Physics, Fluids & Plasmas
J. E. Menard, J. P. Allain, D. J. Battaglia, F. Bedoya, R. E. Bell, E. Belova, J. W. Berkery, M. D. Boyer, N. Crocker, A. Diallo, F. Ebrahimi, N. Ferraro, E. Fredrickson, H. Frerichs, S. Gerhardt, N. Gorelenkov, W. Guttenfelder, W. Heidbrink, R. Kaita, S. M. Kaye, D. M. Kriete, S. Kubota, B. P. LeBlanc, D. Liu, R. Lunsford, D. Mueller, C. E. Myers, M. Ono, J. -K. Park, M. Podesta, R. Raman, M. Reinke, Y. Ren, S. A. Sabbagh, O. Schmitz, F. Scotti, Y. Sechrest, C. H. Skinner, D. R. Smith, V. Soukhanovskii, T. Stoltzfus-Dueck, H. Yuh, Z. Wang, I. Waters, J. -W. Ahn, R. Andre, R. Barchfeld, P. Beiersdorfer, N. Bertelli, A. Bhattacharjee, D. Brennan, R. Buttery, A. Capece, G. Canal, J. Canik, C. S. Chang, D. Darrow, L. Delgado-Aparicio, C. Domier, S. Ethier, T. Evans, J. Ferron, M. Finkenthal, R. Fonck, K. Gan, D. Gates, I. Goumiri, T. Gray, J. Hosea, D. Humphreys, T. Jarboe, S. Jardin, M. A. Jaworski, B. Koel, E. Kolemen, S. Ku, R. J. La Haye, F. Levinton, N. Luhmann, R. Maingi, R. Maqueda, G. Mckee, E. Meier, J. Myra, R. Perkins, F. Poli, T. Rhodes, J. Riquezes, C. Rowley, D. Russell, E. Schuster, B. Stratton, D. Stutman, G. Taylor, K. Tritz, W. Wang, B. Wirth, S. J. Zweben
Article
Physics, Fluids & Plasmas
E. D. Fredrickson, E. Belova, N. N. Gorelenkov, M. Podesta, R. E. Bell, N. A. Crocker, A. Diallo, B. P. LeBlanc
Article
Instruments & Instrumentation
G. Wang, T. L. Rhodes, N. A. Crocker, W. A. Peebles, K. Barada
REVIEW OF SCIENTIFIC INSTRUMENTS
(2018)
Article
Physics, Fluids & Plasmas
S. M. Kaye, D. J. Battaglia, D. Baver, E. Belova, J. W. Berkery, V. N. Duarte, N. Ferraro, E. Fredrickson, N. Gorelenkov, W. Guttenfelder, G. Z. Hao, W. Heidbrink, O. Izacard, D. Kim, I Krebs, R. La Haye, J. Lestz, D. Liu, L. A. Morton, J. Myra, D. Pfefferle, M. Podesta, Y. Ren, J. Riquezes, S. A. Sabbagh, M. Schneller, F. Scotti, V Soukhanovskii, S. J. Zweben, J. W. Ahn, J. P. Allain, R. Barchfeld, F. Bedoya, R. E. Bell, N. Bertelli, A. Bhattacharjee, M. D. Boyer, D. Brennan, G. Canal, J. Canik, N. Crocker, D. Darrow, L. Delgado-Aparicio, A. Diallo, C. Domier, F. Ebrahimi, T. Evans, R. Fonck, H. Frerichs, K. Gan, S. Gerhardt, T. Gray, T. Jarboe, S. Jardin, M. A. Jaworski, R. Kaita, B. Koel, E. Kolemen, D. M. Kriete, S. Kubota, B. P. LeBlanc, F. Levinton, N. Luhmann, R. Lunsford, R. Maingi, R. Maqueda, J. E. Menard, D. Mueller, C. E. Myers, M. Ono, J-K Park, R. Perkins, F. Poli, R. Raman, M. Reinke, T. Rhodes, C. Rowley, D. Russell, E. Schuster, O. Schmitz, Y. Sechrest, C. H. Skinner, D. R. Smith, T. Stotzfus-Dueck, B. Stratton, G. Taylor, K. Tritz, W. Wang, Z. Wang, I Waters, B. Wirth
Article
Physics, Fluids & Plasmas
E. Belova, E. D. Fredrickson, J. B. Lestz, N. A. Crocker
PHYSICS OF PLASMAS
(2019)
Article
Physics, Fluids & Plasmas
J. B. Lestz, N. N. Gorelenkov, E. V. Belova, S. X. Tang, N. A. Crocker
PHYSICS OF PLASMAS
(2020)
Article
Physics, Fluids & Plasmas
J. B. Lestz, N. N. Gorelenkov, E. V. Belova, S. X. Tang, N. A. Crocker
PHYSICS OF PLASMAS
(2020)
Article
Physics, Fluids & Plasmas
W. W. Heidbrink, M. A. Van Zeeland, M. E. Austin, N. A. Crocker, X. D. Du, G. R. McKee, D. A. Spong
Summary: The study focuses on the stability of the beta-induced Alfven eigenmode (BAE) in DIII-D plasmas, revealing unstable behavior under specific conditions with mode frequencies close to theoretical estimates and exhibiting rapid chirping. BAE sensitivity to beam heating power and injection geometry highlights their importance in driving stability, with modes interacting strongly over a narrow range of q.
Article
Physics, Multidisciplinary
S. X. Tang, T. A. Carter, N. A. Crocker, W. W. Heidbrink, J. B. Lestz, R. Pinsker, K. E. Thome, M. A. Van Zeeland, E. Belova
Summary: Fast-ion driven Alfven waves close to the ion cyclotron frequency were stabilized in a fusion research plasma for the first time through a controlled energetic ion density ramp. The wave amplitude scaling with injection rate is consistent with collisional saturation theory near marginal stability for single mode. The wave was identified as a shear-polarized global Alfven eigenmode excited by Doppler-shifted cyclotron resonance with sub-Alfvenic energetic ions, a first in fusion research plasmas.
PHYSICAL REVIEW LETTERS
(2021)
Article
Instruments & Instrumentation
L. Zeng, N. A. Crocker, T. L. Rhodes, W. A. Peebles
Summary: New capabilities of fast-sweep frequency-modulated profile reflectometry are explored and applied to measure electron density perturbations and radial profiles induced by coherent modes in DIII-D plasma. The analysis of high frequency phase perturbations and resolution profiles provides valuable insights into the radial structures and fluctuations of electron density due to different plasma modes. These new measurements further advance the development of non-invasive diagnostic tools for fast-ion-driven modes in burning plasmas like ITER.
REVIEW OF SCIENTIFIC INSTRUMENTS
(2021)
Article
Physics, Fluids & Plasmas
W. W. Heidbrink, G. J. Choi, M. A. Van Zeeland, M. E. Austin, G. H. Degrandchamp, D. A. Spong, A. Bierwage, N. A. Crocker, X. D. Du, P. Lauber, Z. Lin, G. R. McKee
Summary: The study found that beta-induced Alfven eigenmodes (BAEs) generated with deuterium neutral beam injection (NBI) are at least as unstable in mixed hydrogen and deuterium plasmas as in pure deuterium plasmas, but stable when generated with hydrogen NBI. Additionally, low frequency modes (LFMs) are not affected by changes in beam species, indicating that LFMs are not driven by high-energy beam ions.
Article
Physics, Multidisciplinary
X. D. Du, R. J. Hong, W. W. Heidbrink, X. Jian, H. Wang, N. W. Eidietis, M. A. Van Zeeland, M. E. Austin, Y. Liu, N. A. Crocker, T. L. Rhodes, K. Sarkimaki, A. Snicker, W. Wu, M. Knolker
Summary: The study observed a thermal ion driven bursting instability with rapid frequency chirping, attributed to an Alfvenic ion temperature gradient mode, in the DIII-D tokamak. This mode can lead to changes in magnetic topology at the plasma edge and potentially cause minor disruption events.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Fluids & Plasmas
N. A. Crocker, S. X. Tang, K. E. Thome, J. B. Lestz, E. Belova, A. Zalzali, R. O. Dendy, W. A. Peebles, K. K. Barada, R. Hong, T. L. Rhodes, G. Wang, L. Zeng, T. A. Carter, G. H. DeGrandchamp, W. W. Heidbrink, R. Pinsker
Summary: Novel internal measurements and analysis of ion cyclotron frequency range fast-ion driven modes in DIII-D are presented. Observations indicate the presence of coherent ion cyclotron emission (ICE) with high wave number and extended spatial structure localized in the edge, consistent with magnetosonic cyclotron instability or electrostatic instability mechanisms. The amplitude modulation of these edge ICE modes is correlated with edge localized modes (ELM), suggesting ELM-induced fast-ion transport.