In this paper, the dynamics of a magnetization undergoing a radiation-damping based feedback radio-frequency field is investigated both theoretically and experimentally. It is shown that due to the presence of relaxation the evolution equations predict the existence of self-sustained maser pulses. This phenomenon is a consequence of the competition between two different processes, namely, relaxation and a precession about a magnetization-dependent radio-frequency field. Experiments show the existence of periodic revivals of the free induction decay over unusually long periods of time, on the order of tens of seconds.
REFERENCES
1.
2.
A. Abragam, The Principles of Nuclear Magnetism (Clarendon, Oxford, 1961).
3.
4.
5.
A.
Louis-Joseph
, D.
Abergel
, and J.-Y.
Lallemand
, J. Biomol. NMR
5
, 212
(1995
).6.
C.
Anklin
, M.
Rindlisbacher
, G.
Otting
, and F. H.
Laukien
, J. Magn. Reson.
106
, 199
(1995
).7.
D.
Abergel
, A.
Louis-Joseph
, and J.-Y.
Lallemand
, Chem. Phys. Lett.
262
, 465
(1996
).8.
D.
Abergel
, A.
Louis-Joseph
, and J.-Y.
Lallemand
, J. Chem. Phys.
112
, 6365
(2000
).9.
10.
R.
Hobson
and R.
Kayser
, J. Magn. Reson.
20
, 458
(1975
).11.
T.
Barbara
, J. Magn. Reson.
98
, 608
(1992
).12.
J. A. Guckenheimer and P. Holmes, Nonlinear Oscillations, Dynamical Systems, and Bifurcations of Vector Fields (Springer, New York, 1983).
13.
D. K. Arrowsmith and M. Place, Differential Systems: Differential Equations, Maps, and Chaotic Behavior (Chapman and Hall, New York, 1992).
14.
This effect was in fact anticipated some time ago; see J. Jeener, P. Broakaert, and A. Vlassenbroek, Collective effects in high resolution liquid NMR, Lecture Notes for the 14th Waterloo NMR Summer School, June 16–21, 1997.
15.
16.
This content is only available via PDF.
© 2002 American Institute of Physics.
2002
American Institute of Physics
You do not currently have access to this content.