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Title: Observation of neoclassical-like impurity transport in the q less than or equal to 1 region of the PBX tokamak

Technical Report ·
DOI:https://doi.org/10.2172/6088326· OSTI ID:6088326

Charge-dependent convective impurity transport is observed in the central core of PBX H-mode discharges by measuring radial profiles for both low- and high-Z intrinsic impurities in the presence of strong sawtooth activity. Transport coefficients are derived by simulating the data with a diffusive/convective transport model which includes an internal disruption model. The time evolving Z/sub eff/ profile and central metallic densities are fitted during the quiescent phase between internal disruptions to yield a diffusion coefficient of D = 1 x 10/sup 3/ cm/sup 2//s for all species and an inward convective speed of v = 2.2 x 10/sup 2/ (r/a) cm/s for oxygen and carbon and v = 1.1 x 10/sup 3/ (r/a) cm/s for metals. These transport coefficients are in quantitative agreement with simple cylindrical neoclassical estimates for the region within q less than or equal to 1. 17 refs., 4 figs.

Research Organization:
Princeton Plasma Physics Laboratory (PPPL), Princeton, NJ (United States)
DOE Contract Number:
AC02-76CH03073
OSTI ID:
6088326
Report Number(s):
PPPL-2313; ON: DE86007534
Resource Relation:
Other Information: Portions of this document are illegible in microfiche products. Original copy available until stock is exhausted
Country of Publication:
United States
Language:
English