We investigate fluxon dynamics in isolated long Josephson junctions. In con
trast to usual long Josephson junctions, where fluxons are described by a s
ine-Gordon equation, fluxons in the isolated junction obey a double sine-Go
rdon (DSG) equation. Due to the competition between the two sine terms in t
he DSG equation, pi-pi link oscillations appear as a unique feature of DSG
system. We numerically study these new oscillations for the purpose of find
ing junction parameters in experimental observations. (C) 2001 Elsevier Sci
ence B.V. All rights reserved.