Neutron sawtooth behavior in the PLT, DIII-D, and TFTR tokamaks
The effect of the sawtooth instability on the 2.5 MeV neutron emission in the PLT, DIII-D, and TFTR tokamaks is studied. In thermonuclear plasmas, the instability typically results in a 20% reduction in emission. The time evolution of the thermonuclear neutron signal suggests that the sawtooth crash consists of four phases. First, the electron density profile flattens rapidly (in /approximately/30..mu..sec on PLT) but, in some cases, there is little associated change in neutron emission, suggesting that most reacting ions remain confined in the sawtooth region but do not completely mix. After the electron sawtooth, the ions continue to mix, resulting in a /approximately/10% reduction in neutron emission in /approximately/0.5 msec. The emission then decays more slowly during the final two phases. Thermalization of reacting ions on a /approximately/3/tau//sub ii/ time scale accounts for only /approximately/20% of the slow drop. Most of the slow drop seems to be caused by loss of ion energy from the mixing region (an ion heat pulse). 36 refs., 15 figs., 1 tabs.
- Research Organization:
- Princeton Plasma Physics Lab. (PPPL), Princeton, NJ (United States)
- DOE Contract Number:
- AC02-76CH03073
- OSTI ID:
- 6637937
- Report Number(s):
- PPPL-2558; ON: DE89004619
- Resource Relation:
- Other Information: Portions of this document are illegible in microfiche products
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
DOUBLET-3 DEVICE
PLASMA INSTABILITY
PLT DEVICES
TFTR TOKAMAK
ELECTRON DENSITY
ELECTRON TEMPERATURE
ICR HEATING
NEUTRON EMISSION
NUMERICAL ANALYSIS
CLOSED PLASMA DEVICES
EMISSION
HEATING
HIGH-FREQUENCY HEATING
INSTABILITY
MATHEMATICS
PLASMA HEATING
THERMONUCLEAR DEVICES
THERMONUCLEAR REACTORS
TOKAMAK DEVICES
TOKAMAK TYPE REACTORS
700107* - Fusion Energy- Plasma Research- Instabilities