First measurements of electron temperature and density with divertor Thomson scattering in radiative divertor discharges on DIII-D

JOURNAL OF NUCLEAR MATERIALS

卷:241

Article; Proceedings Paper

Allen, SL ; Hill, DN ; Carlstrom, TN ; Nilson, DG ; Stockdale, R ; Hsieh, CL ; Petrie, TW ; Leonard, AW ; Ryutov, D ; Porter, GD ; Maingi, R ; Wade, MR ; Cohen, R ; Nevins, W ; Fenstermacher, ME ; Wood, RD ; Lasnier, CJ ; West, WP ; Brown, MD

关键词: DIII-D;    plasma temperature diagnostic;    detached plasma;    poloidal divertor;    divertor plasma;   

DOI  :  10.1016/S0022-3115(97)80106-7

来源: Elsevier

【 摘 要 】

We have obtained the first measurements of n(e) and T-e in the DIII-D divertor region with a multi-pulse (20 Hz) divertor Thomson scattering (DTS) system. Eight measurement locations are distributed vertically up to 21 cm above the divertor plate. Two-dimensional distributions have been obtained by sweeping the divertor plasma across the DTS measurement location. Several operating modes have been studied, including Ohmic, L-mode, ELMing K-mode, and radiative divertor operation with puffing of D-2 and impurities. Mapping of the data to either the (L-pol, phi) or (R, Z) planes with the EFIT equilibrium is used to analyze the 2D profiles. We find that in ELMing H-mode: n(e), T-e, and P-e are relatively constant along field lines from the X-point to the divertor plate, especially near the separahix field line. With D, puffing, the DTS profiles indicate that T-e in a large part of divertor region below the X-point is dramatically reduced from similar to 30-40 eV in ELMing H-mode to 1-2 eV. This results in a fairly uniform low-T-e divertor, with an increased electron density in the range of 2 to 4 x 10(20) m(-3). Detailed comparisons of the spatial profiles of n(e), T-e, and electron pressure P-e, are presented for several operating modes. In addition, these data are compared with initial calculations from the UEDGE fluid code.

【 授权许可】

Free