Study of MARFE during lower hybrid current drive in HT-7 tokamak
Lower hybrid current drive (LHCD) experiments have been carried out to achieve high performance for long pulse operation in the HT-7 superconducting tokamak. Multifaceted asymmetric radiation from the edge (MARFE) phenomena, is observed in LHCD plasmas when P LH > 160 kW and edge safety factor...
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Published in | Physics letters. A Vol. 346; no. 4; pp. 305 - 309 |
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Main Authors | , , |
Format | Journal Article |
Language | English |
Published |
Elsevier B.V
17.10.2005
|
Subjects | |
Online Access | Get full text |
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Summary: | Lower hybrid current drive (LHCD) experiments have been carried out to achieve high performance for long pulse operation in the HT-7 superconducting tokamak. Multifaceted asymmetric radiation from the edge (MARFE) phenomena, is observed in LHCD plasmas when
P
LH
>
160
kW
and edge safety factor
q
(
a
)
is slightly less than 6.5 and has been studied in this Letter. Studies show that the critical density of MARFE onset is observed in the region of
Z
eff
1
/
2
f
GW
=
0.6
–
0.9
, where
f
GW
=
n
¯
e
n
GW
(here
n
¯
e
is the maximum line average electron density and
n
GW
is the Greenwald density). These MARFEs generally appear to have the same characteristics as high
f
GW
MARFEs and are positionally stable throughout the LHCD pulse. |
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ISSN: | 0375-9601 1873-2429 |
DOI: | 10.1016/j.physleta.2005.08.029 |