Session GP1 - Poster Session IV.
POSTER session, Tuesday afternoon, October 30
Exhibit Hall B,
Initial spectroscopic measurements have been made of the Stark Broadening of the Balmer alpha and beta lines produced in the luminous cloud surrounding deuterium pellets injected into JET H-mode plasmas heated by NBI in combination with ICRH [1]. Pellets were injected in an extended sequence of 10 or more pellets launched from the high field side (HFS). One pellet data point was also captured for low field side (LFS) launch. These lineshape measurements are time integrated over the full duration of each observable pellet event, and they generally reflect the maximum broadening produced in the pellet cloud. For HFS launch the broadening is generally consistent from pellet to pellet in the sequence with a typical Balmer-alpha linewidth (FWHM) of \sim1.5nm. However, in some pellet sequences linewidths vary from \sim1.2 to 2nm. The observed broadening is suitable for the determination of electron density in the pellet ablation cloud. These density results are discussed. [1] Lang, EPS, Portugal (2001), P3.012