Accession Number : AD0921240

Title :   Microgradient Cesium Magnetometer Development.

Descriptive Note : Technical rept. 4 Oct 72-3 Oct 73,

Corporate Author : SINGER CO LITTLE FALLS NJ KEARFOTT DIV

Personal Author(s) : Simpson, James H.

Report Date : 21 DEC 1973

Pagination or Media Count : 51

Abstract : Apparatus has been designed and constructed that incorporates the experimental techniques for achieving high signal-to-noise ratios and sufficiently long relaxation times, in order to obtain a gradient magnetometer with a differential sensitivity of 0.1 milligamma/ft. The apparatus consists of two magnetic resonance sensors operated in a self oscillating mode and spaced eighteen inches apart. The resonance medium (cesuim vapor) is contained in vacuum, wall-coated cells. The field differential is obtained by means of phase comparison of the two simultaneously observed cesium resonances. In preliminary tests in the laboratory ambient magnetic fields, required signal-to-noise ratios have been shown to be attainable. Techniques have been developed for producing cesium resonance cells with stable longitudinal relaxation times in excess of 150 ms. An analysis of the useful sensitivity of gradient magnetometers in the presence of wave noise was carried out. It is shown that the full sensitivity of 0.1 milligamma/ft. can be used with appropriate orientation of the gradient device and/or with signal processing. (Author)

Descriptors :   (*MAGNETOMETERS, SENSITIVITY), (*METAL VAPORS, OPTICAL PUMPING), (*CESIUM, RELAXATION TIME), (*GRADIOMETERS, MAGNETIC FIELDS), (*MAGNETIC ANOMALY DETECTION, DIRECTION FINDING), PHASE MEASUREMENT, SIGNAL TO NOISE RATIO, MAGNETIC RESONANCE, SPINNING(MOTION), COATINGS, GLASS, ZEEMAN EFFECT, BUFFERS, BEAM SPLITTING, INFRARED RADIATION, CIRCULAR, LINEAR SYSTEMS, TRANSVERSE, ORIENTATION(DIRECTION), POLARIZATION.

Subject Categories : Test Facilities, Equipment and Methods
      Direction Finding
      Magnetic & Electric Fld Detection & Detectors
      Optics

Distribution Statement : APPROVED FOR PUBLIC RELEASE