Abstract
Measurements from the JET neutron profile monitor are analyzed tomographically to deduce the 2-D spatial distribution of neutron emissivity during NBI heating both before and after sawtooth crashes. In a discharge where the global neutron emission decreases slightly to 5/6 of the pre-crash rate of nearly 1016 n s-1, the axial emissivity drops much more to only 1/6 of the pre-crash value. The sources of neutron emissivity are analyzed with an analytic Fokker-Planck formulation. The main change in neutron emissivity is due to fast ion redistribution during a sawtooth crash and a decrease in beam-beam-produced emissivity. The deduced fast ion redistribution is consistent with other observations of sawtooth behaviour in JET.
Original language | English |
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Article number | 001 |
Pages (from-to) | 277-287 |
Number of pages | 11 |
Journal | Plasma Physics and Controlled Fusion |
Volume | 33 |
Issue number | 4 |
DOIs | |
State | Published - 1991 |
Externally published | Yes |