A Compact Optical Fiber Magnetometer for Irradiated Environments*

Circuit components exposed to high intensity, pulsed X-ray radiation experience internal and external Electromagnetic Pulse (EMP) effects that create large currents that cause damage to individual components. These currents generate magnetic fields within the device and knowledge of these magnetic fields is important to validate models of a particular component’s response to EMP effects. Presently, these fields are measured with small induction coils that are limited by electromagnetic interference susceptibility, finite size constraints, and proximity within a test object. The Compact Optical Fiber for Extreme Environments (COFFEE) system describes a low profile sensor that measures magnetic fields based on the Faraday effect in a small section of rare earth ion doped fiber. The system will be capable of capturing the transient magnetic field effects on the relevant nanosecond timescales while the optical fiber based sensor will be more robust to EMI and X-ray radiation than traditional induction coils. Initial results with the magnetometer and progress towards the complete system will be discussed.