Pulsed high magnetic field sensor using polymethyl methacrylate

Abstract

We propose and demonstrate the use of polymethyl methacrylate (PMMA) for sensing elements based on the Faraday effect for the measurement of a pulsed high magnetic field generated by helical magnetic flux compression generators (HMCGs). The magneto-optic properties of sensing elements made with PMMA are investigated. The inherent linear birefringence is substantially suppressed by carefully annealing PMMA blocks. The Verdet constant of V = 3.251 rad T−1 m−1 and the normalized temperature dependence of VL (the product of the Verdet constant and the length of the sensing element) of −2.04 × 10−4 °C−1 are measured in the annealed PMMA material. The pulsed high magnetic field of up to ∼27 kG is measured by the sensors made from annealed PMMA and the results are compared with those measured by inductive probes. They are in good agreement within ±1.5%. As an application, the annealed PMMA sensor is used in the measurement of a pulsed magnetic field generated by explosive-driven HMCGs.