Magnetic field measurements in low density plasmas using paramagnetic Faraday rotator glass

Abstract

Paramagnetic Faraday rotator glass (rare-earth doped borosilicate) with a high Verdet constant will be used to measure the magnetic field inside of low density Helium plasmas (T(e) ~ 5 eV, T(i) ~ 1 eV) with a density of n ~ 10(12) cm(-3). Linearly polarized light is sent through the glass such that the plane of polarization is rotated by an angle that depends on the strength of the magnetic field in the direction of propagation and the length of the crystal (6 mm). The light is then passed into an analyzer and photo-detector setup to determine the change in polarization angle. This setup can detect magnetic fields up to 5 kG with a resolution of <5 G and a temporal resolution on the order of a nanosecond. The diagnostic will be used to characterize the structure and evolution of laser-driven collisionless shocks in large magnetized plasmas.

Dynamics of exploding plasmas in a large magnetized plasma

“…Future experiments will take advantage of improved diagnostics 45,46,53,54 and a new plasma-source 23 that supports higher plasma ion densities in excess of 10 13 cm À3 and will reduce the ion-inertial length to a few cm. In addition, a new kilojoule-class laser system 24 will increase the on-target energy tenfold and will drive pistons as large as D B ¼ 50 cm over sufficient scale lengths (>10 c=x pi ) to launch fullblown collisionless shocks in the ambient plasma 55,56 The higher density will also decrease the Alfv en wavelength k A and thus increase the ratio D B =k A , which is expected to improve coupling to shear-waves.…”

Magneto-optic probe measurements in low density-supersonic jets

“…In presence of smaller magnetic fields, Faraday rotation measurements are still possible, but they require the use of a small birefringent crystal placed within the plasma to increase the rotation. Magneto-optical probes, relying on this enhancement of the Faraday rotation, have been tested with large current-driven magnetic fields [19][20][21]. However, to our knowledge, they have not yet been used to measure smaller fluctuating magnetic fields within a plasma, nor tested against other diagnostics methods.…”

Research on the method of measuring solution concentration based on the magneto-optical effect in permanent magnetic fields

“…Then they reviewed the application of magneto-optic films in non-destructive evaluation (NDE). Clark et al (2012) measured the magnetic field in low density plasmas using a paramagnetic Faraday rotator glass with a high Verdet constant. A Faraday rotator glass is a modulation device based on the magneto-optical effect.…”