1. Magnetic Field Sensing via Acoustic Sensing Fiber with Metglas® 2605SC Cladding Wires
- Author
-
Zach Dejneka, Daniel Homa, Joshua Buontempo, Gideon Crawford, Eileen Martin, Logan Theis, Anbo Wang, and Gary Pickrell
- Subjects
optic sensors ,magnetostriction ,magnetism ,magnetic field sensors ,distributed acoustic sensors ,Applied optics. Photonics ,TA1501-1820 - Abstract
Magnetic field sensing has the potential to become necessary as a critical tool for long-term subsurface geophysical monitoring. The success of distributed fiber optic sensing for geophysical characterization provides a template for the development of next generation downhole magnetic sensors. In this study, Sentek Instrument’s picoDAS is coupled with a multi-material single mode optical fiber with Metglas® 2605SC cladding wire inclusions for magnetic field detection. The response of acoustic sensing fibers with one and two Metglas® 2605SC cladding wires was evaluated upon exposure to lateral AC magnetic fields. An improved response was demonstrated for a sensing fiber with in-cladding wire following thermal magnetic annealing (~400 °C) under a constant static transverse magnetic field (~200 μT). A minimal detectable magnetic field of ~500 nT was confirmed for a sensing fiber with two 10 μm cladding wires. The successful demonstration of a magnetic field sensing fiber with Metglas® cladding wires fabricated via traditional draw processes sets the stage for distributed measurements and joint inversion as a compliment to distributed fiber optic acoustic sensors.
- Published
- 2024
- Full Text
- View/download PDF