  We explore novel junction configurations as an extension of our established
Focused Ion Beam-based low TC SNS Junction fabrication technique. By milling a
circular trench (diameter 1 micron, width 50 nm) in a 125 nm Nb 75 nm Cu
bilayer we define a superconducting island connected to the bulk of the film by
a normal metal barrier and entirely enclosed in-plane by the superconducting
film. The circular junction properties can be probed by depositing an
insulating layer over the device and drilling a 0.3 micron diameter hole down
to the island to allow a Nb via to be deposited. Device behavior has been
studied at 4.2 K. An SNS-like current voltage characteristic and Shapiro steps
are observed. It is in terms of magnetic field behavior that the device
exhibits novel characteristics: as the device is entirely enclosed in type II
superconductor, when a magnetic field is applied perpendicular to the plane of
the film, only quantized flux can enter the junction. Hence as applied magnetic
field is increased the junction critical current is unchanged, then abruptly
suppressed as soon as a flux quantum enters (close to the expected value of
lower critical field for the film).
