Ray chaos in optical cavities based upon standard laser mirrors

We present a composite optical cavity made of standard laser mirrors; the cavity consists of a suitable combination of stable and unstable cavities. In spite of its very open nature the composite cavity shows ray chaos, which may be either soft or hard, depending on the cavity configuration. This opens a new, convenient route for experimental studies of the quantum aspects of a chaotic wave field.Comment: 4 pages, 3 figures, 1 tabl

Metamorphosis and Taxonomy of Andreev Bound States

We analyze the spatial and energy dependence of the local density of states in a SNS junction. We model our system as a one-dimensional tight-binding chain which we solve exactly by numerical diagonalization. We calculate the dependence of the Andreev bound states on position, phase difference, gate voltage, and coupling with the superconducting leads. Our results confirm the physics predicted by certain analytical approximations, but reveal a much richer set of phenomena beyond the grasp of these approximations, such as the metamorphosis of the discrete states of the normal link (the normal bound states) into Andreev bound states as the leads become superconducting.Comment: 23 pages, 15 figure

Intravascular Young's modulus reconstruction using a parametric finite element model

IntraVascular UltraSound (IVUS) elastography may be used to detect vulnerable, rupture prone plaques, which are held responsible for the majority of acute coronary syndromes. IVUS elastography accomplishes this by visualising local incremental radial strain of arteries, in so-called elastograms. These are an artifactual image of the Young's modulus distribution and therefore, they cannot be directly interpreted as plaque component images. To overcome this limitation, we developed a modulography tool, which converts an elastogram into a modulogram, i.e. a Young's modulus image. This tool is especially developed for reconstruction of plaques having a lipid pool covered by a cap. Reconstruction consists of matching the strain image output, calculated with a parametric finite element model (PFEM) representation of a vulnerable plaque, to an elastogram by iteratively updating the PFEM parameters. The modulography tool successfully reconstructed both geometry and composition of a vulnerable plaque, solely using an elastogram as inpu

Cryostat for the SSC 6T magnet option

A design has been developed for a SSC 6T option dipole magnet cryostat. The design criteria that defines the basic parameters and performance requirements are discussed. Details of the single phase assembly, suspension, insulation, thermal shields, vacuum vessels and interconnections are presented. Results of the experimental program in support of the design effort are discussed