Neutral atom temperature and flow measurements in the edge region of the Alcator C-mod tokamak

Spectral line shifts have been observed in the D-alpha transition of neutra l deuterium in the Alcator C-mod [I. H. Hutchinson, Proceedings of the IEEE 13th Symposium on Fusion Engineering (IEEE, Piscataway, 1990), Vol. 1, p. 13] tokamak and interpreted as Doppler shifts due to a neutral flow of appr oximately 5x10(3) m/s. The emission originates from plasma at the inner wal l, as indicated by the Zeeman patterns of the transition. The direction of the flow changes when the plasma transitions from a limited to a diverted c onfiguration. In all cases, the flows are directed toward the point of cont act with the wall or divertor plate. Narrow spectral profiles have been obs erved for the D-alpha transition near the midplane and within the divertor. Temperatures not higher than 0.86 eV are indicated for the divertor measur ements. A difference in plasma conditions for separate locations along a si ngle line of sight has been observed. (C) 2001 American Institute of Physic s.