Comparison of collective Thomson scattering signals due to fast ions in ITER scenarios with fusion and auxiliary heating

Salewski, M.; Asunta, O.; Eriksson, L.‐G.; Bindslev, H.; Hynönen, V.; Korsholm, S. B.; Kurki-Suonio, T.; Leipold, F.; Méo, F.; Michelsen, Poul; Nielsen, S. K.; Roenby, Johan

doi:10.1088/0741-3335/51/3/035006

Cited by 46 publications

(66 citation statements)

References 35 publications

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“…With our prescription we can compute tomographies for any set of fastion measurements, in particular those obtained with CTS or FIDA or other fast-ion charge exchange spectroscopy (FICXS) that detects other light than D α . A mix of diagnostics would also be possible as will be relevant to the CTS/FIDA system at ASDEX Upgrade, the CTS/FICXS system at LHD [35,36] and the proposed two-view CTS system for ITER [37][38][39][40] in particular if it can be combined with FICXS [32]. However, only one of the two CTS views is an enabled ITER diagnostic.…”

Section: Introductionmentioning

confidence: 99%

Tomography of fast-ion velocity-space distributions from synthetic CTS and FIDA measurements

Salewski¹,

Geiger²,

Nielsen³

et al. 2012

Nucl. Fusion

122

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We compute tomographies of 2D fast-ion velocity distribution functions from synthetic collective Thomson scattering (CTS) and fast-ion D α (FIDA) 1D measurements using a new reconstruction prescription. Contradicting conventional wisdom we demonstrate that one single 1D CTS or FIDA view suffices to compute accurate tomographies of arbitrary 2D functions under idealized conditions. Under simulated experimental conditions, single-view tomographies do not resemble the original fast-ion velocity distribution functions but nevertheless show their coarsest features. For CTS or FIDA systems with many simultaneous views on the same measurement volume, the resemblance improves with the number of available views, even if the resolution in each view is varied inversely proportional to the number of views, so that the total number of measurements in all views is the same. With a realistic four-view system, tomographies of a beam ion velocity distribution function at ASDEX Upgrade reproduce the general shape of the function and the location of the maxima at full and half injection energy of the beam ions. By applying our method to real many-view CTS or FIDA measurements, one could determine tomographies of 2D fast-ion velocity distribution functions experimentally.

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Section: Introductionmentioning

confidence: 99%

Tomography of fast-ion velocity-space distributions from synthetic CTS and FIDA measurements

Salewski¹,

Geiger²,

Nielsen³

et al. 2012

Nucl. Fusion

122

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show abstract

“…At relatively large frequency shifts, here roughly beyond ±0.5 GHz, CTS measurements provide information about fast, nonthermal ion populations, e.g. from neutral beam heating [4][5][6][7][8][9][10][11][12][13][14] or from fusion reactions in future experiments with burning plasmas [15][16][17][18][19] . At lower frequency shifts, in the bulk ion region of the spectrum, CTS measurements provide information about thermal ion populations including properties such as the ion temperature and drift a) mspe@fysik.dtu.dk velocity (i.e.…”

mentioning

confidence: 99%

Resolving the bulk ion region of millimeter-wave collective Thomson scattering spectra at ASDEX Upgrade

Stejner

Nielsen

Jacobsen

et al. 2014

Review of Scientific Instruments

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Collective Thomson scattering (CTS) measurements provide information about the composition and velocity distribution of confined ion populations in fusion plasmas. The bulk ion part of the CTS spectrum is dominated by scattering off fluctuations driven by the motion of thermalized ion populations. It thus contains information about the ion temperature, rotation velocity and plasma composition. To resolve the bulk ion region and access this information, we installed a fast acquisition system capable of sampling rates up to 12.5 GS/s in the CTS system at ASDEX Upgrade. CTS spectra with frequency resolution in the range of 1 MHz are then obtained through direct digitization and Fourier analysis of the CTS signal. We here describe the design, calibration and operation of the fast receiver system and give examples of measured bulk ion CTS spectra showing the effects of changing ion temperature, rotation velocity and plasma composition.

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“…8 For example, a CTS system for the next-step fusion device ITER is foreseen. 9 Waveguide filters are also used in mm-wave receivers for ata) vfurtula@gmail.com b) msal@fysik.dtu.dk mospheric science. For example, a waveguide highpass filter installed in a ground-based mm-wave receiver is used to acquire mesospheric carbon monoxide (CO) data.…”

Section: Introductionmentioning

confidence: 99%

W-band waveguide bandpass filter with E-plane cut

Furtula

Salewski

2014

Review of Scientific Instruments

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In this paper, we present a design and measurements of a five-section bandpass filter with a passband from 96 to 106 GHz. The insertion loss is less than 1.4 dB in the passband, and the rejection is better than 40 dB in the range from 115 to 142 GHz. We use transmission line coupling theory based on Tchebyscheff's synthesis in order to provide an initial guess for the geometrical parameters of the filter such as cavity lengths and coupling widths. The filter is manufactured from brass in two halves in the E-plane cut topology. The S-parameters of the filter are measured and compared with the simulations. The measured passband insertion loss is approximately 0.4 dB worse than in the simulation, and the measured passband width is approximately 3.4% narrower. The measured filter attenuation roll-off corresponds well to the simulation. We also compare our S-parameter measurements of the E-plane filter with corresponding measurements of a very similar H-plane filter. The transmission and reflection characteristics of the E-plane filter are better than those of the H-plane filter.

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Comparison of collective Thomson scattering signals due to fast ions in ITER scenarios with fusion and auxiliary heating

Cited by 46 publications

References 35 publications

Tomography of fast-ion velocity-space distributions from synthetic CTS and FIDA measurements

Tomography of fast-ion velocity-space distributions from synthetic CTS and FIDA measurements

Resolving the bulk ion region of millimeter-wave collective Thomson scattering spectra at ASDEX Upgrade

W-band waveguide bandpass filter with E-plane cut

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