Period doubling cascade in mercury, a quantitative measurement

Abstract
Observation of the period doubling cascade in a Rayleigh-Bénard experiment in mercury. The experimental cell has an aspect ratio Γ = 4 and contains four convective rolls. A DC magnetic field of 270 G is applied along the convective roll axis. The measured Feigenbaum number is δ = 4.4. The ratio of the successive subharmonics is of the order of 14 dB for the lowest measured subharmonics