Fiber optic, Faraday rotation current sensor
At the Second Megagauss Conference in 1979, there were reports of experiments that used the Faraday magneto-optic effect in a glass rod to measure large electric current pulses or magnetic fields. Since then we have seen the development of single-mode optical fibers that can carry polarized light in a closed loop around a current load. A fiber optic Faraday rotation sensor will integrate the flux, instead of sampling it at a discrete point, to get a measurement independent of the current distribution. Early Faraday rotation experiments using optical fibers to measure currents dealt with problems such as fiber birefringence and difficulties in launching light into the tiny fiber cores. We have built on those experiments, working to reduce the effects of shocks and obtaining higher bandwidths, absolute calibration, and computerized recording and data analysis, to develop the Faraday rotation sensors into a routine current diagnostic. For large current pulses we find reduced sensitivity to electromagnetic interference and other backgrounds than for Rogowski loops; often the fiber optic sensors are useful where conductive probes cannot be used at all. In this paper we describe the fiber optic sensors and some practical matters involved in fielding them.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States); National Bureau of Standards, Boulder, CO (United States)
- DOE Contract Number:
- W-7405-ENG-36
- OSTI ID:
- 5746103
- Report Number(s):
- LA-UR-86-2084; CONF-860703-2; ON: DE86012413
- Resource Relation:
- Conference: 4. international conference on megagauss magnetic-field generation and related topics, Santa Fe, NM, USA, 14 Jul 1986
- Country of Publication:
- United States
- Language:
- English
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