It is demonstrated that a magnetic island chain formed by a saturated tearing instability in a toroidal magnetic fusion device can lock to a special class of externally generated magnetic perturbation in a stabilizing phase. The theoretical apparatus needed to design such perturbations is outlined. These special perturbations—which are termed “designer” error fields—could be used to control the amplitudes of tearing modes in toroidal magnetic fusion experiments without the requirement of fast phase modulation. This type of control would be far more feasible in a reactor environment than conventional active feedback control via external magnetic perturbations.

1.
T.
Taylor
,
E. J.
Strait
,
L. L.
Lao
et al.,
Phys. Plasmas
2
,
2390
(
1995
).
2.
T.
Ivers
,
E.
Eisner
,
A.
Garafalo
et al.,
Phys. Plasmas
3
,
1926
(
1996
).
3.
O.
Sauter
,
R. J.
LaHaye
,
Z.
Chang
et al.,
Phys. Plasmas
4
,
1654
(
1997
).
4.
J. S.
Sarff
,
N. E.
Lanier
,
S. C.
Prager
, and
M. R.
Stoneking
,
Phys. Rev. Lett.
78
,
62
(
1997
).
5.
M. N.
Rosenbluth
,
Plasma Phys. Controlled Fusion
41
,
A99
(
1999
).
6.
H. P.
Furth
,
J.
Killeen
, and
M. N.
Rosenbluth
,
Phys. Fluids
6
,
459
(
1963
).
7.
J. A.
Wesson
,
Nucl. Fusion
18
,
87
(
1978
).
8.
R.
Carrera
,
R. D.
Hazeltine
, and
M.
Kotschenreuther
,
Phys. Fluids
29
,
899
(
1986
).
9.
P. H.
Rutherford
,
Phys. Fluids
16
,
1903
(
1973
).
10.
R. B.
White
,
D. A.
Monticello
,
M. N.
Rosenbluth
, and
B. V.
Waddell
,
Phys. Fluids
20
,
800
(
1977
).
11.
A.
Thyagaraja
,
Phys. Fluids
24
,
1716
(
1981
).
12.
A. H.
Boozer
,
Phys. Fluids
27
,
2055
(
1984
).
13.
Z.
Chang
and
J. D.
Callen
,
Nucl. Fusion
30
,
219
(
1990
).
14.
V. V. Arsenin, L. I. Artemenkov, N. V. Ivanov et al., in Plasma Physics and Controlled Nuclear Fusion Research 1978, Proceedings of the 16th International Conference, Innsbruck (International Atomic Energy Agency, Vienna, 1979), Vol. 1, p. 233.
15.
A. W.
Morris
,
T. C.
Hender
,
J.
Hugill
et al.,
Phys. Rev. Lett.
64
,
1254
(
1990
).
16.
G. A.
Navratil
,
C.
Cates
,
M. E.
Mauel
et al.,
Phys. Plasmas
5
,
1855
(
1998
).
17.
E.
Lazzaro
and
M. F. F.
Nave
,
Phys. Fluids
31
,
1623
(
1988
).
18.
J.
Norris
,
Plasma Phys. Controlled Fusion
31
,
699
(
1989
).
19.
A.
Thyagaraja
,
Plasma Phys. Controlled Fusion
32
,
155
(
1990
).
20.
M. S.
Chu
,
H.
Ikezi
, and
T. H.
Jensen
,
Phys. Fluids
27
,
472
(
1984
).
21.
The standard large aspect ratio ordering is R0/a≫1, where R0 and a are the major and minor radii of the plasma, respectively.
22.
The conventional definition of this parameter is β=2μ0〈p〉/〈B2〉, where 〈⋯〉 denotes a volume average, p is the plasma pressure, and B is the magnetic field strength.
23.
W. A.
Newcomb
,
Ann. Phys. (N.Y.)
10
,
232
(
1960
).
24.
R.
Fitzpatrick
,
Phys. Plasmas
6
,
1168
(
1999
).
25.
R.
Fitzpatrick
and
F. L.
Waelbroeck
,
Phys. Plasmas
7
,
4983
(
2000
).
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