Non-resonant System Research Articles

The Prospects for High Sensitivity Gravitational Antennae

The sensitivity of a resonant gravitational wave detector which is necessary for the detection of pulses from asymmetric stellar collapses or from black-hole collisions in nearby galaxies is examined. Limitations on this sensitivity due to the resonating quality of the detector, thermal noise, and reaction of the detection system upon the detector are studied. No severe difficulties for the detection of the above-mentioned pulses are expected. For the detection of pulses from a cluster at the galactic center, a nonresonant system based on Doppler ranging to a drag-free satellite would be more appropriate. At present the sensitivity of Doppler-ranging is still two orders of magnitude below the requirements.

Sensitivity of Radio Frequency Measurements in the Presence of Oscillator Noise

The inherent sensitivity of an rf measuring system and the effect of the system transmission characteristics on the detectability of the rf source noise are examined. The results are applied to resonant reflection and transmission systems and to a nonresonant transmission system. The conventional reflection cavity paramagnetic resonance system is discussed in detail, and the conclusion is that this configuration will be source noise limited at power levels above 1 mW. Unconventional configurations, such as a dual mode induction cavity or a dual cavity transmission system, would have to be used to achieve higher sensitivity.

Matching and backing problems in piezoelectric readout systems

The effects of matching and backing on the performance of the piezoelectric ceramic transducers used in delay line readout systems for spark chambers are considered. Analysis and probe design are presented for a nonresonant matching system intended for pulse-strain detection application. Particular emphasis is laid on determination of the input acoustical impedance of an exponential matching connector. The input acoustical impedance is calculated and plotted as a function of (a) the normalized frequency, (b) the specific acoustical impedances ratio between the backing material and the matching connector material, and (c) the ratio of the large end diameter-to-small end diameter of the connector.

Optical Avalanche Laser

A neodymium-glass laser device is described which employs amplified spontaneous emission in a nonresonant system to obtain a high brightness output pulse. The spontaneous avalanche obtained was in a 70-nsec pulse of approximately 1-GW power confined to a 1-mrad-full-angle beam. The output brightness was sufficient to produce unfocused air breakdown. Included are design criteria and an analysis of the characteristics of the avalanche pulse.

Transmission Line Measurement of Narrow Linewidth Ferromagnetic Samples (Correspondence)

Measurement of ferromagnetic resonance linewidths over a range of microwave frequencies is facilitated by the use of a nonresonant waveguide system. The loading effect encountered in such a transmission line system, however, becomes significant when the linewidth is less than a few tens of oersteds. The effect of transmission line loading was avoided by the use of an automatic compensation network.