Active beam spectroscopy for ITER

Hellermann, M. von; Barnsley, R.; Biel, W.; Delabie, E.; Hawkes, N.; Jaspers, Rje Roger; Johnson, D.; Klinkhamer, F.; Lischtschenko, O.; Marchuk, O.; Schunke, B.; Singh, Mahesh Chand; Snijders, B.; Summers, H. P.; Thomas, D. M.; Tugarinov, S. N.; Vasu, P.

doi:10.1016/j.nima.2010.04.011

Cited by 19 publications

(9 citation statements)

References 4 publications

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“…A simulation package has been used to assess the feasibility of fast helium CX measurements on ITER by modelling the expected CX spectrum [12,13]. The code simulates the geometry of the tokamak and the neutral beam injection system.…”

Section: Simulation Package For Charge Exchange Spectroscopymentioning

confidence: 99%

Feasibility of non-thermal helium measurements with charge exchange spectroscopy on ITER

Kappatou¹,

Delabie²,

Jaspers³

et al. 2012

Nucl. Fusion

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The use of active charge exchange recombination spectroscopy (CXRS) as a diagnostic for fusion-produced alpha particles on ITER is constrained by the signal-to-noise ratio, which is determined by the intensity of the line of interest, the optical throughput of the diagnostic, the neutral beam penetration, and the intensity of bremsstrahlung radiation. The CX spectral line for fast ions has been modelled together with the expected background emission and we present the signal-to-noise ratios calculated as a function of the diagnostic design parameters. Combining the CXRS data from both the heating and the diagnostic neutral beams on ITER, information on fast ions with energies up to 1 MeV can be obtained for the parameters of the ITER core CXRS diagnostic design. To achieve this, energy binning of the signal is used (100 keV bins or larger), in order to improve the signal-to-noise ratio, with a time resolution of 2 s. The time resolution of the measurement can be improved using a higher throughput spectrometer, but this is ultimately limited by the amount of light from the neutral beam that can be collected. Despite the challenges and the fact that the results are not as optimistic as previously assumed, it is concluded that useful information on fast helium density profiles can be obtained using CXRS on ITER.

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Section: Simulation Package For Charge Exchange Spectroscopymentioning

confidence: 99%

Feasibility of non-thermal helium measurements with charge exchange spectroscopy on ITER

Kappatou¹,

Delabie²,

Jaspers³

et al. 2012

Nucl. Fusion

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“…The detection limits (minimum density, time and spatial resolution) may be different for all these quantities and very much depend on the profile and available current density of the DNB. A summary of the requirements is given, for instance, in [3].…”

Section: Spectral Rangementioning

confidence: 99%

Status of the R&D activities to the design of an ITER core CXRS diagnostic system

Mertens

Bardawil

Baross

et al. 2015

Fusion Engineering and Design

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“…For charge exchange measurements, the optimum beam energy is around 100 keV=amu, based on signal-to-noise calculations for core light ion measurements using the putative ITER scenario profiles. 98,101,102 Therefore, a dedicated hydrogen DNB at 100 keV and 17 A equivalent current will also be installed. 103 This beam will also be based on negative ion source technology permitting a common R&D path to the needed performance for both systems.…”

Section: A Development Of Techniques For the Present Generation Of Pmentioning

confidence: 99%

Beams, brightness, and background: Using active spectroscopy techniques for precision measurements in fusion plasma research

Thomas

2012

Physics of Plasmas

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The use of an injected neutral beam-either a dedicated diagnostic beam or the main heating beams-to localize and enhance plasma spectroscopic measurements can be exploited for a number of key physics issues in magnetic confinement fusion research, yielding detailed profile information on thermal and fast ion parameters, the radial electric field, plasma current density, and turbulent transport. The ability to make these measurements has played a significant role in much of our recent progress in the scientific understanding of fusion plasmas. The measurements can utilize emission from excited state transitions either from plasma ions or from the beam atoms themselves. The primary requirement is that the beam "probe" interacts with the plasma in a known fashion. Advantages of active spectroscopy include high spatial resolution due to the enhanced localization of the emission and the use of appropriate imaging optics, background rejection through the appropriate modulation and timing of the beam and emission collection=detection system, and the ability of the beam to populate emitter states that are either nonexistent or too dim to utilize effectively in the case of standard or passive spectroscopy. In addition, some active techniques offer the diagnostician unique information because of the specific quantum physics responsible for the emission. This paper will describe the general principles behind a successful active spectroscopic measurement, emphasize specific techniques that facilitate the measurements and include several successful examples of their implementation, briefly touching on some of the more important physics results. It concludes with a few remarks about the relevance and requirements of active spectroscopic techniques for future burning plasma experiments. V C 2012 American Institute of Physics. [http://dx.

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Active beam spectroscopy for ITER

Cited by 19 publications

References 4 publications

Feasibility of non-thermal helium measurements with charge exchange spectroscopy on ITER

Feasibility of non-thermal helium measurements with charge exchange spectroscopy on ITER

Status of the R&D activities to the design of an ITER core CXRS diagnostic system

Beams, brightness, and background: Using active spectroscopy techniques for precision measurements in fusion plasma research

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