An automatic frequency-sweeping SQUID susceptometer

Gradiometric micro-SQUID susceptometer for scanning measurements of mesoscopic samples.

We have fabricated and characterized micro-SQUID susceptometers for use in low-temperature scanning probe microscopy systems. The design features the following: a 4.6 mum diameter pickup loop; an integrated field coil to apply a local field to the sample; an additional counterwound pickup-loop/field-coil pair to cancel the background signal from the applied field in the absence of the sample; m...

Strongly driven frequency-sweeping events in plasmas.

A generic model of a kinetic plasma formed from a source and sink is presented which without instability would form a strongly unstable state due to a single mode. Instead, the resulting wave-particle resonant interaction maintains the distribution near a marginally stable state through the continual production of fast frequency-sweeping modes that sweep unidirectionally (upward in our case) th...

Dimensional Metrology and Frequency Sweeping Interferometry

Frequency Sweeping of Phase Space Structures

Holes and clumps, spontaneously formed in the nonlinear development of a single mode driven by a weakly destabilizing kinetic distribution function in a dissipative medium, were expected to persist for an appropriate collisional time scale. However, Fokker-Planck calculations for the nonlinear system abruptly break down in the course of the calculation for some initial conditions. We nd that th...

An Automatic Fingerprint Classification Algorithm

Manual fingerprint classification algorithms are very time consuming, and usually not accurate. Fast and accurate fingerprint classification is essential to each AFIS (Automatic Fingerprint Identification System). This paper investigates a fingerprint classification algorithm that reduces the complexity and costs associated with the fingerprint identification procedure. A new structural algorit...