Beam Physics Seminar

Friday, April 19, 2002, 10:00 AM
ARC Bldg. Room 231/233

Visible Light Diagnostics from the Alcator C-Mod Tokamak

Benjamin L. Welch
Dilon Technologies

Visible light emission from the Alcator C-Mod tokamak has been used to determine quantitative information about the edge and divertor regions. This emission originated primarily from hydrogen/deuterium entering the plasma from the walls. The light was collected from various regions of the plasma via optical fibers and coupled to a high-resolution grating spectrograph. Line width measurements were used to determine the temperature and density of the plasma using Doppler Broadening of the Ha emission and Stark broadening of the high-n members of the Balmer series. Line shift measurements were used to determine the magnetic field from the Zeeman pattern, the plasma flow velocity from the Doppler shift, and the ratio of the concentrations of the isotopes of hydrogen from the isotope shift.

Talk Slides:     PDF

(Coffee & Cookies before the seminar starting 9:30 AM)