Abstract
A particle in the Hénon-Heiles potential can escape when its energy is above the threshold value
E
th
=1/6
. We report a theoretical study on the the escape rates near threshold. We derived an analytic formula for the escape rate as a function of energy by exploring the property of chaos. We also simulated the escaping process by following the motions of a large number of particles. Two algorithms are employed to solve the equations of motion. One is the Runge-Kutta-Fehlberg method, and another is a recently proposed fourth order symplectic method. Our simulations show the escape of H
e
´
non-Heiles system follows exponential laws. We extracted the escape rates from the time dependence of particle numbers in the H
e
´
non-Heiles potential. The extracted escape rates agree with the analytic result.