Investigation of the elastic enhancement factor in microwave chaotic cavities in the presence of significantly opened channels

Abstract

The elastic enhancement factor F is commonly used to study the relationship between elastic and inelastic scattering processes. In chaotic scattering the elastic processes are known to be enhanced over the inelastic ones. Most thorough experimental studies of F are possible by using microwave setups simulating the quantum systems. In this paper the elastic enhancement factor FM(1)(γtot) is studied in a microwave chaotic quarter bow-tie cavity emulating a chaotic two-dimensional quantum billiard with preserved time reversal symmetry in the presence of significantly opened channels M with the total absorption strength γtot. The experimental results are obtained for 2 ≤ M ≤ 9 open channels characterized by the average transmission coefficient 0.34 < T < 0.98, moderate internal absorption strength γ = 0.9-2.8, and the total absorption strength γtot = 1.6-11.6. We show that the experimental results are close to the theoretical predictions. Moreover, the spectral properties of the microwave quarter bow-tie billiard are studied for M = 2 channels using missing level statistics. They comply with those of generic time reversal invariant and classically fully chaotic systems.