Determination of “Isotropic” Magnetic Fields in Pulsed Plasmas: New Approach

A new approach for a spectroscopic measurement of magnetic fields is proposed. The method is based on an analysis of line‐shapes of different fine‐structure components of the same atomic multiplet. The method is applicable to the detection of magnetic fields in situations where the magnetic fields have various directions in the region viewed by the diagnostic system, or if their direction varies during the time of observation, as is often the case in e.g. laser‐produced or pinch plasmas. This is in contrary to the known diagnostic methods that are based on detecting an anisotropy in either the emitted radiation or in the dispersion properties of the medium, and, thus, are inapplicable in cases of such “isotropic” magnetic field distributions. Furthermore, the technique here described allows for the observation of magnetic fields in the presence of other rather dominating line‐broadening mechanisms (the Stark and the Doppler effects) in the plasma. Suggestions for measurements of magnetic fields in high‐power laser and pinch experiments are discussed.