Chaos in a Gravo-Magneto Neutron Trap

Book · Tue Dec 31 23:00:00 EST 2013

DOI:https://doi.org/10.1142/9789814571678_0006· OSTI ID:1265372

Bowman, James David ^[1]; Penttila, Seppo I ^[1]

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1. ORNL

Performance of a neutron trap for cleaning quasi-trapped neutrons depends on what fraction of the neutron orbit are chaotic. In this paper, we argue that the Lyapunov characteristic exponent is a good meaure the chaos because regular orbits have Lyapunov exponent zero and chaotic orbits of a given energy have a common non-zero Lyapunov exponent. The Lyapunov exponent describes the rate of exponential divergence for infinitesimally perturbed initial conditions[1,2]. We show how to calculate the fraction of chaotic trajectories using Benettin's algorithm [1]. We evaluate the fraction of non-chaotic orbits for a trap that consists of a vertical multipole, gravity, and a current loop at the bottom of the trap.

• Research Organization: Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Spallation Neutron Source
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 1265372
• Country of Publication: United States
• Language: English