Tokamak:	TFTR
Pulse Number:	91472
Contact: 	E. Synakowski
Institution:	PPPL, Princeton University
Date of Shot:	February 1, 1996
Analysis Code:	TRANSP
Run number:	91472a02
Analysis Date:	August 15, 1997
Assumptions: 	Zeff profile determined from carbon density profile 
		measured by CXRS, normalized to a single chord-
		integral VB measurement.  Prior to the start of NBI, 
		Ti profile is calculated assuming chii = 15 x 
		neoclassical, which is the value observed in other 
		expts. During NBI, Ti and Vphi are measured by 
		CXRS.
		
Shot Desc.: 	Supershot to L-mode perturbation caused by carbon 
		bloom event. The bloom starts at about 4.0 seconds, 
		after approximately 30 MJ of beam energy has been 
		deposited in the plasma over a period of 1200 ms of 
		beam injection. During the bloom, the central ion 
		temperature drops a factor of three over a period of 
		~200-300 msec. Some of this decrease can be 
		attributed directly to increased beam attenuation 
		caused by the higher edge density; beam power 
		delivered to the core decreases 30% after 200 ms and 
		50% after 300 ms. However, the response of the ion 
		temperature is considerably stronger than would be 
		expected from the decreased core power delivery. 
		Time-dependent transport analysis by TRANSP 
		concludes that the ion thermal diffusivity in the core 
		(r/a = 0.25-0.35) increases about a factor of five by 
		4.2 seconds, i.e. about 200 ms into the bloom event. 
				
		Interestingly, the fractional decrease in central ion 
		temperature during the bloom is much greater than 
		the corresponding change in edge ion temperature. 
		Indeed, at 4.2 seconds the edge Ti has hardly 
		changed, while the central ion temperature drops by 
		nearly a factor of two. This result should be 
		particularly useful for testing models that have a 
		strong marginal-stability character, which typically 
		find that the edge Ti is an important factor in 
		controlling central Ti.
 
Publication:	This shot is unpublished.  The physics of carbon 
		blooms is described in  Nuclear Fusion 31 (1991) p. 
		1811 by A. T. Ramsey. 
Other Info: