Validating and optimizing mismatch tolerance of Doppler backscattering measurements with the beam model (invited)

Hall-Chen, Valerian Hongjie; Damba, Julius; Parra, Felix I.; Pratt, Quinn T.; Michael, Clive A.; Peng, Shi; Rhodes, Terry L.; Crocker, Neal A.; Hillesheim, J. C.; Hong, Rongjie; Ni, Shikang; Peebles, W. A.; Png, Ching Eng; Ruiz Ruiz, Juan

doi:10.1063/5.0101805

Validating and optimizing mismatch tolerance of Doppler backscattering measurements with the beam model (invited)

Journal Article · Tue Oct 25 00:00:00 EDT 2022 · Review of Scientific Instruments

DOI:https://doi.org/10.1063/5.0101805· OSTI ID:1905785

^[1]; ^[2]; ^[3]; ^[2]; ^[2]; ^[4]; ^[2]; ^[2]; Hillesheim, J. C. ^[4]; ^[2]; ^[5]; Peebles, W. A. ^[2]; ^[6]; ^[7]

Agency for Science, Technology and Research (A*STAR) (Singapore). Institute of High Performance Computing; Culham Science Centre, Abingdon (United Kingdom). Culham Centre for Fusion Energy (CCFE), EURATOM/UKAEA Fusion Association; Univ. of Oxford (United Kingdom)
Univ. of California, Los Angeles, CA (United States)
Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
Culham Science Centre, Abingdon (United Kingdom). Culham Centre for Fusion Energy (CCFE), EURATOM/UKAEA Fusion Association
Univ. of Cambridge (United Kingdom)
Agency for Science, Technology and Research (A*STAR) (Singapore). Institute of High Performance Computing
Univ. of Oxford (United Kingdom)

In this work, we use the beam model of Doppler backscattering (DBS), which was previously derived from beam tracing and the reciprocity theorem, to shed light on mismatch attenuation. This attenuation of the backscattered signal occurs when the wavevector of the probe beam’s electric field is not in the plane perpendicular to the magnetic field. Correcting for this effect is important for determining the amplitude of the actual density fluctuations. Previous preliminary comparisons between the model and Mega-Ampere Spherical Tokamak (MAST) plasmas were promising. In this work, we quantitatively account for this effect on DIII-D, a conventional tokamak. We compare the predicted and measured mismatch attenuation in various DIII-D, MAST, and MAST-U plasmas, showing that the beam model is applicable in a wide variety of situations. Finally, we performed a preliminary parameter sweep and found that the mismatch tolerance can be improved by optimizing the probe beam’s width and curvature at launch. This is potentially a design consideration for new DBS systems.

View Accepted Manuscript (DOE)

Research Organization:: Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)

Sponsoring Organization:: Engineering and Physical Sciences Research Council (EPSRC); RCUK Energy Programme; USDOE

Grant/Contract Number:: AC02-09CH11466; SC0019005; SC0019007; SC0019352; SC0020649

OSTI ID:: 1905785

Alternate ID(s):: OSTI ID: 1894530

Journal Information:: Review of Scientific Instruments, Journal Name: Review of Scientific Instruments Journal Issue: 10 Vol. 93; ISSN 0034-6748

Publisher:: American Institute of Physics (AIP)Copyright Statement

Country of Publication:: United States

Language:: English

References (17)

A feasibility study for a Doppler reflectometer system in the JT-60SA tokamak Carralero, D.; Happel, T.; Estrada, T. Fusion Engineering and Design, Vol. 173 https://doi.org/10.1016/j.fusengdes.2021.112803	journal	December 2021
TORBEAM, a beam tracing code for electron-cyclotron waves in tokamak plasmas Poli, E.; Peeters, A. G.; Pereverzev, G. V. Computer Physics Communications, Vol. 136, Issue 1-2 https://doi.org/10.1016/s0010-4655(01)00146-1	journal	May 2001
Doppler backscattering system for measuring fluctuations and their perpendicular velocity on Tore Supra Hennequin, P.; Honoré, C.; Truc, A. Review of Scientific Instruments, Vol. 75, Issue 10 https://doi.org/10.1063/1.1787920	journal	October 2004
Doppler reflectometer system in the stellarator TJ-II Happel, T.; Estrada, T.; Blanco, E. Review of Scientific Instruments, Vol. 80, Issue 7 https://doi.org/10.1063/1.3160106	journal	July 2009
A novel multi-channel quadrature Doppler backward scattering reflectometer on the HL-2A tokamak Shi, Zhongbing; Zhong, Wulu; Jiang, Min Review of Scientific Instruments, Vol. 87, Issue 11 https://doi.org/10.1063/1.4966680	journal	November 2016
Optimized quasi-optical cross-polarization scattering system for the measurement of magnetic turbulence on the DIII-D tokamak Rhodes, T. L.; Lantsov, R.; Wang, G. Review of Scientific Instruments, Vol. 89, Issue 10 https://doi.org/10.1063/1.5035427	journal	October 2018
Study of density fluctuations in plasmas by small-angle CO2 laser scattering Slusher, R. E.; Surko, C. M. Physics of Fluids, Vol. 23, Issue 3 https://doi.org/10.1063/1.863016	journal	January 1980
W-band millimeter-wave back-scattering system for high wavenumber turbulence measurements in LHD Tokuzawa, T.; Tanaka, K.; Tsujimura, T. Review of Scientific Instruments, Vol. 92, Issue 4 https://doi.org/10.1063/5.0043474	journal	April 2021
A remote gain controlled and polarization angle tunable Doppler backward scattering reflectometer Wen, J.; Shi, Z. B.; Zhong, W. L. Review of Scientific Instruments, Vol. 92, Issue 6 https://doi.org/10.1063/5.0043676	journal	June 2021
Doppler backscattering for spherical tokamaks and measurement of high- k density fluctuation wavenumber spectrum in MAST Hillesheim, J. C.; Crocker, N. A.; Peebles, W. A. Nuclear Fusion, Vol. 55, Issue 7 https://doi.org/10.1088/0029-5515/55/7/073024	journal	June 2015
Doppler reflectometry for the investigation of propagating density perturbations Hirsch, M.; Holzhauer, E.; Baldzuhn, J. Plasma Physics and Controlled Fusion, Vol. 43, Issue 12 https://doi.org/10.1088/0741-3335/43/12/302	journal	October 2001
On application of the reciprocity theorem to calculation of a microwave radiation signal in inhomogeneous hot magnetized plasmas Piliya, A. D.; Popov, A. Yu Plasma Physics and Controlled Fusion, Vol. 44, Issue 5 https://doi.org/10.1088/0741-3335/44/5/301	journal	April 2002
Spatial and wavenumber resolution of Doppler reflectometry Gusakov, E. Z.; Surkov, A. V. Plasma Physics and Controlled Fusion, Vol. 46, Issue 7 https://doi.org/10.1088/0741-3335/46/7/012	journal	June 2004
Beam model of Doppler backscattering Hall-Chen, Valerian H.; Parra, Felix I.; Hillesheim, Jon C. Plasma Physics and Controlled Fusion, Vol. 64, Issue 9 https://doi.org/10.1088/1361-6587/ac57a1	journal	July 2022
Interpreting radial correlation Doppler reflectometry using gyrokinetic simulations Ruiz Ruiz, J.; Parra, F. I.; Hall-Chen, V. H. Plasma Physics and Controlled Fusion, Vol. 64, Issue 5 https://doi.org/10.1088/1361-6587/ac5916	journal	April 2022
Comparison of Doppler back-scattering and charge exchange measurements of E × B plasma rotation in the DIII-D tokamak under varying torque conditions Pratt, Q.; Rhodes, T.; Chrystal, C. Plasma Physics and Controlled Fusion, Vol. 64, Issue 9 https://doi.org/10.1088/1361-6587/ac8614	journal	August 2022
Spatial and spectral resolution of the plasma Doppler reflectometry Bulanin, V. V.; Yafanov, M. V. Plasma Physics Reports, Vol. 32, Issue 1 https://doi.org/10.1134/s1063780x06010053	journal	January 2006

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