STUDY AND INVESTIGATION OF AN IMPROVED PROTON MASER ANTENNA
Abstract
This effort covers applied research in nuclear magnetic resonance for the improvement of detection sensitivity and for the provision of band tuning for an electromagnetic energy sensor. The small sizes of this sensor, compared with conventional antennas, makes it usable for the detection of extremely low and very low frequencies in hardened communication complexes where the antenna is buried underground and the transmitted energy propagates through the earth's crust. The report presents results of a study and investigation of techniques for improving the performance of a Proton Maser Antenna, a new sensor technique for the ELF-VLF frequency region. Problems of increasing threshold sensitivity and providing band tuning of the antenna were considered. The heterodyne method was utilized for VLF tuning. This method uses eddy current flux-cancelling coils for micron-switching purposes. The incoming signal is magnetically chopped at a predetermined rate and is translated into a fixed intermediate frequency. By the utilization of this technique, the frequency range of the antenna is extended from 100 Hz to 100 MH2 without appreciable degradation in sensitivity. Partial success was achieved in the effort concerned with increasing the sensitivity of the antenna. A new coil box was constructed in order to increase the sample flow volume by 50%. This undertaking should theoretically increase the sensitivity by 22%.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 01, 1966
- Accession Number
- AD0803189
Entities
People
- Clarence O. Thornburg
- Gordon Guttrich
- Jonathan Webster