Data from several diagnostics employed on the Large s Experiment (LSX) field‐reversed theta pinch were analyzed to seek correlation between plasma distortions and the confinement properties of the field‐reversed configurations (FRC’s) formed. In particular, an array of Bθ probes was used to determine separatrix movement, which might indicate the existence of low‐order modes, such as a tilt instability. No correlation between the quality of confinement and signal was observed. The parameter s, equal to the average number of ion gyroradii inside the separatrix, has been postulated as a measure of FRC stability with values above 2, leading to instability and loss of confinement. However, the confinement observed in experiments conducted over a large range of s (1<s<8) appeared to correlate more with the shape of the equilibrium radial density profile produced during formation rather than s. Flatter profiles correlated with poorer confinement.

1.
W. A.
Newcomb
,
Phys. Fluids
23
,
2296
(
1980
).
2.
M. N.
Rosenbluth
and
M. N.
Bussac
,
Nucl. Fusion
19
,
489
(
1979
).
3.
D. C.
Barnes
,
J. L.
Schwartzmeier
,
H. R.
Lewis
, and
C. E.
Seyler
,
Phys. Fluids
29
,
2616
(
1986
).
4.
A.
Ishida
,
H.
Momota
, and
L. C.
Steinhauer
,
Phys. Fluids
31
,
3024
(
1988
).
5.
L. C.
Steinhauer
and
A.
Ishida
,
Phys. Fluids B
2
,
2422
(
1990
).
6.
A.
Ishida
,
R.
Kanno
, and
L. C.
Steinhauer
,
Phys. Fluids B
4
,
1280
(
1992
).
7.
L. C.
Steinhauer
and
A.
Ishida
,
Phys. Fluids B
4
,
645
(
1992
).
8.
A. L.
Hoffman
and
J. T.
Slough
,
Nucl. Fusion
33
,
27
(
1993
).
9.
J. T.
Slough
,
A. L.
Hoffman
, and
R. D.
Milroy
,
Phys. Fluids B
1
,
840
(
1989
).
10.
M.
Tuszewski
,
Nucl. Fusion
28
,
2033
(
1988
).
11.
M.
Tuszewski
,
D. P.
Taggart
,
R. E.
Chrien
,
D. J.
Rej
,
R. E.
Siemon
, and
B. L.
Wright
,
Phys. Fluids B
3
,
2856
(
1991
).
12.
J. T.
Slough
,
A. L.
Hoffman
,
R. D.
Milroy
,
E. A.
Crawford
,
M.
Cecik
,
R.
Maqueda
,
G. A.
Wurden
,
Y.
Ito
, and
A.
Shiokawa
,
Phys. Rev. Lett.
69
,
2212
(
1992
).
13.
M.
Tuszewski
,
Rev. Sci. Instrum.
61
,
2937
(
1990
).
14.
J. T.
Slough
and
R. D.
Milroy
,
Rev. Sci. Instrum.
61
,
3280
(
1990
).
15.
R. D.
Milroy
,
D. C.
Barnes
,
R. C.
Bishop
, and
R. B.
Webster
,
Phys. Fluids B
1
,
1225
(
1989
).
16.
J. T. Slough, in Conference Record of the 1988 IEEE International Conference on Plasma Science, Seattle, WA (Institute of Electrical and Electronics Engineers, New York, 1988), IEEE Catalog No. 88CH2559–3.
17.
M. N.
Rosenbluth
,
N. A.
Krall
, and
N.
Rostoker
,
Nucl. Fusion
Suppl., Pt.
1
,
143
(
1962
).
18.
R. F.
Post
,
Nucl. Fusion
27
,
1577
(
1987
).
19.
D. S.
Harned
,
Phys. Fluids
26
,
1320
(
1983
).
20.
J. T. Slough, A. L. Hoffman, R. D. Milroy, E. A. Crawford, Y. Ito, G. A. Wurden, in Europhysics Conference Abstracts, 18th European Conference on Controlled Fusion and Plasma Physics, Berlin, 3–7 June 1991 (European Physical Society, Geneva, 1991), Part II, p. 297.
21.
R. E. Siemon, R. E. Chrien, W. N. Hugrass, S. Okada, D. J. Rej, D. P. Taggart, M. Tuszewski, R. B. Webster, B. L. Wright, J. T. Slough, E. A. Crawford, A. L. Hoffman, R. D. Milroy, G. C. Vlases, R. D. Brooks, B. Kronast, Z. A. Pietrzyk, R. Raman, and R. Smith, Plasma Physics and Controlled Nuclear Fusion Research, 1988, Proceedings of the 12th International Conference, Nice, 1988 (International Atomic Energy Agency, Vienna, 1989), Vol. 2, p. 517.
22.
L. C.
Steinhauer
and
A.
Ishida
,
Phys. Fluids B
2
,
2422
(
1990
).
23.
R.
Kanno
,
A.
Ishida
, and
L. C.
Steinhauer
,
Bull. Am. Phys. Soc.
37
,
1609
(
1992
).
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