Calibrated helium and carbon ion flow measurements in the DIII-D divertor plasma

Allen, S. L.; Samuell, C. M.; Meyer, W. H.; Jaervinen, A. E.; Porter, G. D.; Rognlien, T.

doi:10.1016/j.nme.2018.12.015

Calibrated helium and carbon ion flow measurements in the DIII-D divertor plasma

Journal Article · Tue Feb 26 04:00:00 EST 2019 · Nuclear Materials and Energy

DOI:https://doi.org/10.1016/j.nme.2018.12.015· OSTI ID:1882283

Allen, S. L. ^[1]; Samuell, C. M. ^[1]; Meyer, W. H. ^[1]; Jaervinen, A. E. ^[1]; Porter, G. D. ^[1]; Rognlien, T. ^[1]

Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

To explore the influence of drifts on ion flows in the DIII-D divertor and Scrape-Off-Layer (SOL), a calibrated Coherence Imaging System (CIS) views the lower divertor. A new tuneable calibration laser and precision wavemeter provide the rest wavelength for CIII 465 nm plasma emissions resulting in ≤ 1 km/s uncertainty in ion velocities that are in the range of 30 km/s in the divertor plasma. The 2-D line-integrated velocity images have been tomographically inverted to obtain maps of ion velocity. Both He⁺and C²⁺ ion velocity maps were measured in both directions of the toroidal magnetic field B_T, and C²⁺ images were obtained in attached and detached L- and H-mode plasmas. The measured C²⁺ velocities are in the range of 20-30km/s and are compared with UEDGE modeling with full drifts. While He II as a main ion is expected to be entrained in the plasma flow, the C²⁺ impurity flow involves the competition between the frictional and ion temperature gradient forces. Both the CIS data and UEDGE modeling agree that the C²⁺ flow is towards the divertor plates, but flips with the direction of B_T. In general, the experimental C²⁺ emission and flow profiles have a wider spatial extent than the UEDGE modeling.

Research Organization:: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)

Sponsoring Organization:: USDOE National Nuclear Security Administration (NNSA)

Grant/Contract Number:: AC52-07NA27344

OSTI ID:: 1882283

Report Number(s):: LLNL-JRNL-757606; 943152

Journal Information:: Nuclear Materials and Energy, Journal Name: Nuclear Materials and Energy Vol. 19; ISSN 2352-1791

Publisher:: ElsevierCopyright Statement

Country of Publication:: United States

Language:: English

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70 PLASMA PHYSICS AND FUSION TECHNOLOGY
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Calibrated helium and carbon ion flow measurements in the DIII-D divertor plasma

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