Laser-induced fluorescence diagnostic for measuring magnetic fields (abstract)

Abstract

A novel, spatially resolved diagnostic is being developed to measure magnetic fields associated with intense ion beam propagation through a low-pressure gas, as is envisioned for ion-driven inertial confinement fusion. The diagnostic technique uses laser-induced fluorescence spectroscopy, and can be varied to measure either small or large fields. Small fields, as expected in ballistic beam transport, produce Zeeman shifts, ΔλZ, much smaller than the transition linewidth Δλ. High sensitivity to measure these sub-Doppler shifts is achieved by a variation on the Babcock technique.Reference 1 Large fields, as expected in self-pinched beam transport, produce ΔλZ larger than Δλ. These ΔλZ will be resolved using a Fabry–Pérot interferometer, in a novel technique similar to that for small fields. Results from benchtop experiments using calibrated B fields for the small-field technique will be presented. Available results from a proof-of-principle experiment for the large-field technique will also be presented.