1 - Nuclear Sciences and Applications - IAEA

578
WEYNANTS et al.
2.06 2.10 2.14
Time (s)
FIG. 6. Time evolution of Te0 before and after RF switch-on at t = 2.102 s (PSF = 1.75 MW,
iie = 2.6 x 10 u cm~ 3 ) (#32470).
04
0.3
2 e,o
0.2
keV]
0.1
0
\
10 20
F (Hzl
(a)
30 40
0
[degrees] \
-90
2.18
• •
(b)
10 20 30 4
F [Hz]
FIG. 7. Amplitude (a) and phase (b) variation of modulated electron energy density weI versus modulation
frequency (F = Q/2ir). The lines are the theoretical results yielding pme = 23, pmin e = 68,
pmini = 92 (all in units of mW-cm' 3 -UVT 1 ). (PMI = 0.35 MW, P^o = 1.0 MW, rse = 30 ms,
rsl = 22 ms, TC = T,- = Tmin = ».;
Te, T, and Tmin are the central confinement times for electrons, deuterons and tail ions
respectively. Linearization of the form X = Xo + X] exp (ifit) makes it possible to
solve for the modulation frequency spectrum of the various quantities. The results
of the procedure are the values of pmc and pmin yielding the best fit for the amplitude
and phase variation of wel and wu with respect to Q, using computed values of TSC,
Tsi and Tei. An example of fitting wel is given in Fig. 7. The interference of the
sawtooth crash with the raw modulation signal [12] demands appropriate measures
[13]. The sum of pmc and pminTs/7se then yields pRF,e, whereas pRF>i equals