TY - JOUR
T1 - Multiresonance effect in type-I edge-localized mode control with low n fields on JET
AU - Liang, Y.
AU - Gimblett, C. G.
AU - Browning, P. K.
AU - Devoy, P.
AU - Koslowski, H. R.
AU - Jachmich, S.
AU - Sun, Y.
AU - Wiegmann, C.
PY - 2010/8/3
Y1 - 2010/8/3
N2 - Multiple resonances in the edge-localized mode (ELM) frequency (fELM) as a function of the edge safety factor q95 have been observed for the first time with an applied low n (=1,2) field on the JET tokamak. Without an n=1 field applied, fELM increases slightly from 20 to 30 Hz by varying the q95 from 4 to 5 in a type-I ELMy H-mode plasma. However, with an n=1 field applied, a strong increase in fELM by a factor of 4-5 has been observed with resonant q95 values, while the fELM increased only by a factor of 2 for nonresonant values. A model, which assumes that the ELM width is determined by a localized relaxation triggered by an unstable ideal external peeling mode, can qualitatively predict the observed resonances when low n fields are applied.
AB - Multiple resonances in the edge-localized mode (ELM) frequency (fELM) as a function of the edge safety factor q95 have been observed for the first time with an applied low n (=1,2) field on the JET tokamak. Without an n=1 field applied, fELM increases slightly from 20 to 30 Hz by varying the q95 from 4 to 5 in a type-I ELMy H-mode plasma. However, with an n=1 field applied, a strong increase in fELM by a factor of 4-5 has been observed with resonant q95 values, while the fELM increased only by a factor of 2 for nonresonant values. A model, which assumes that the ELM width is determined by a localized relaxation triggered by an unstable ideal external peeling mode, can qualitatively predict the observed resonances when low n fields are applied.
UR - http://www.scopus.com/inward/record.url?scp=77955330719&partnerID=8YFLogxK
U2 - 10.1103/PhysRevLett.105.065001
DO - 10.1103/PhysRevLett.105.065001
M3 - Article
AN - SCOPUS:77955330719
SN - 0031-9007
VL - 105
JO - Physical Review Letters
JF - Physical Review Letters
IS - 6
M1 - 065001
ER -