Abstract: A signal generator and signal receiver, as well as method of signal generation and transmission, in which selected unstable periodic orbits of a lossy chaotic system are identified and extracted, and portions of the orbits concatenated together to form a resultant signal. The selected orbits are known to the signal detector a priori. The signal detector detects the transmitted signal by correlation of the received signal with the known extracted orbits, also allowing the detector identify information which the generator imposed onto the signal.

Abstract: An acoustic signal processor that samples acoustic data, performs a spectrum analysis of the sampled acoustic data, stores the acoustic data in corresponding frequency bins, and then filters acoustic data stored in a frequency bin by applying a power-law arithmetic operation to the frequency bin acoustic data, such that the power-law arithmetic operation is adaptively changed based on an order dependent determination of whether the frequency bin acoustic data is representative of noise or clutter, or whether it is representative of a signal of an object.

Abstract: A method for determining the anisotropy of the magnetic susceptibility of a sample includes determining the resonant frequency of the sample in substantially zero magnetic field, the resonant frequency being for flexure vibration in a selected plane of vibration. A second step is applying a uniform dc magnetic field to the sample, the magnetic field having a component in the selected plane of vibration. A third step is determining the resonant frequency of the sample in the presence of the applied magnetic field, the resonant frequency being for flexure vibration in the selected plane. The fourth step is determining the anisotropy of the magnetic susceptibility of the sample, based on the amplitude of the magnetic field component and on the above-determined resonant frequencies.

Abstract: A mass spectrometer is disclosed having a detector that detects the induction of a charge as an ion pulse passes by the detector and provides a representative output signal thereof. The inductive detector output signal is present regardless of the presence or intensity of preceding ion pulses and also the inductive detector is relatively insensitive to the velocity of the charged particles being detected. Further, the inductive detector does not destroy the vast majority of the ion pulses that it detects so that the non-destroyed ion pulses may be further analyzed by spectrometers attached in tandem.

Abstract: A method of and apparatus for controlling the potential of a plasma including a metal-walled chamber and a conductive coil which carries a radio-frequency current and is wrapped around the metal-walled chamber to produce a plasma within the chamber. A filament made of refractory metal has two ends, and a central portion formed in the shape of a probe. The central portion of the filament extends into the interior of the chamber and the two ends of the filament pass through a wall of the chamber to the exterior of the chamber. A heating power supply is connected to the two ends to the filament and to the chamber wall for heating the filament to a predetermined temperature above that of the plasma. The heated filament produces thermionic emissions from the filament to the plasma in order to control the plasma potential and eliminate unipolar arcing at the chamber wall.