Abstract
Understanding the origin of rotation in ion cyclotron resonance frequency (ICRF) heated plasmas is important for predictions for burning plasmas sustained by alpha particles, being characterized by a large population of fast ions and no external momentum input. The angular velocity of the plasma column has been measured in JET H-mode plasmas with pure ICRF heating both for the standard low toroidal magnetic ripple configuration, of about ~0.08% and, for increased ripple values up to 1.5% (Nave et al 2010 Phys. Rev. Lett. 105 105005). These new JET rotation data were compared with the multi-machine scaling of Rice et al (2007 Nucl. Fusion 47 1618) for the Alfvén–Mach number and with the scaling for the velocity change from L-mode into H-mode. The JET data do not fit well any of these scalings that were derived for plasmas that are co-rotating with respect to the plasma current. With the standard low ripple configuration, JET plasmas with large ICRF heating power and normalized beta, βN ≈ 1.3, have a very small co-current rotation, with Alfvén–Mach numbers significantly below those given by the rotation scaling of Rice et al (2007 Nucl. Fusion 47 1618). In some cases the plasmas are actually counter-rotating. No significant difference between the H-mode and L-mode rotation is observed. Typically the H-mode velocities near the edge are lower than those in L-modes. With ripple values larger than the standard JET value, between 1% and 1.5%, H-mode plasmas were obtained where both the edge and the core counter-rotated.
| Original language | English |
|---|---|
| Article number | 074006 |
| Journal | Plasma Physics and Controlled Fusion |
| Volume | 54 |
| Issue number | 7 |
| DOIs | |
| Publication status | Published - 1 Jul 2012 |
| MoE publication type | Not Eligible |
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JET intrinsic rotation studies in plasmas with a high normalized beta and varying toroidal field ripple. / Nave, M. F.F.; Eriksson, L. G.; Giroud, C.; Johnson, T. J.; Kirov, K.; Mayoral, M. L.; Noterdaeme, J. M.; Ongena, J.; Saibene, G.; Sartori, R.; Rimini, F.; Tala, T.; De Vries, P.; Zastrow, K. D.
In: Plasma Physics and Controlled Fusion, Vol. 54, No. 7, 074006, 01.07.2012.Research output: Contribution to journal › Article › Scientific › peer-review
TY - JOUR
T1 - JET intrinsic rotation studies in plasmas with a high normalized beta and varying toroidal field ripple
AU - Nave, M. F.F.
AU - Eriksson, L. G.
AU - Giroud, C.
AU - Johnson, T. J.
AU - Kirov, K.
AU - Mayoral, M. L.
AU - Noterdaeme, J. M.
AU - Ongena, J.
AU - Saibene, G.
AU - Sartori, R.
AU - Rimini, F.
AU - Tala, T.
AU - De Vries, P.
AU - Zastrow, K. D.
PY - 2012/7/1
Y1 - 2012/7/1
N2 - Understanding the origin of rotation in ion cyclotron resonance frequency (ICRF) heated plasmas is important for predictions for burning plasmas sustained by alpha particles, being characterized by a large population of fast ions and no external momentum input. The angular velocity of the plasma column has been measured in JET H-mode plasmas with pure ICRF heating both for the standard low toroidal magnetic ripple configuration, of about ~0.08% and, for increased ripple values up to 1.5% (Nave et al 2010 Phys. Rev. Lett. 105 105005). These new JET rotation data were compared with the multi-machine scaling of Rice et al (2007 Nucl. Fusion 47 1618) for the Alfvén–Mach number and with the scaling for the velocity change from L-mode into H-mode. The JET data do not fit well any of these scalings that were derived for plasmas that are co-rotating with respect to the plasma current. With the standard low ripple configuration, JET plasmas with large ICRF heating power and normalized beta, βN ≈ 1.3, have a very small co-current rotation, with Alfvén–Mach numbers significantly below those given by the rotation scaling of Rice et al (2007 Nucl. Fusion 47 1618). In some cases the plasmas are actually counter-rotating. No significant difference between the H-mode and L-mode rotation is observed. Typically the H-mode velocities near the edge are lower than those in L-modes. With ripple values larger than the standard JET value, between 1% and 1.5%, H-mode plasmas were obtained where both the edge and the core counter-rotated.
AB - Understanding the origin of rotation in ion cyclotron resonance frequency (ICRF) heated plasmas is important for predictions for burning plasmas sustained by alpha particles, being characterized by a large population of fast ions and no external momentum input. The angular velocity of the plasma column has been measured in JET H-mode plasmas with pure ICRF heating both for the standard low toroidal magnetic ripple configuration, of about ~0.08% and, for increased ripple values up to 1.5% (Nave et al 2010 Phys. Rev. Lett. 105 105005). These new JET rotation data were compared with the multi-machine scaling of Rice et al (2007 Nucl. Fusion 47 1618) for the Alfvén–Mach number and with the scaling for the velocity change from L-mode into H-mode. The JET data do not fit well any of these scalings that were derived for plasmas that are co-rotating with respect to the plasma current. With the standard low ripple configuration, JET plasmas with large ICRF heating power and normalized beta, βN ≈ 1.3, have a very small co-current rotation, with Alfvén–Mach numbers significantly below those given by the rotation scaling of Rice et al (2007 Nucl. Fusion 47 1618). In some cases the plasmas are actually counter-rotating. No significant difference between the H-mode and L-mode rotation is observed. Typically the H-mode velocities near the edge are lower than those in L-modes. With ripple values larger than the standard JET value, between 1% and 1.5%, H-mode plasmas were obtained where both the edge and the core counter-rotated.
U2 - 10.1088/0741-3335/54/7/074006
DO - 10.1088/0741-3335/54/7/074006
M3 - Article
AN - SCOPUS:84858734808
VL - 54
JO - Plasma Physics and Controlled Fusion
JF - Plasma Physics and Controlled Fusion
SN - 0741-3335
IS - 7
M1 - 074006
ER -