We report on the preliminary results of a first experiment where the Zeeman effect in the X‐ray range was exploited to monitor the quasi static magnetic field, created by the interaction of an ultra‐short (80 fs) ultra‐intense fs laser pulse with solid matter.
The involved laser intensities ranged between 1018 and 5⋅1019 W/cm2. The target was a 25 μm thick Ti foil. We monitored the X‐ray emissions of the Kα1 and Kα2 lines by means of a spectrometer with 0.3 eV energy resolution and 20 μm spatial resolution. The spectrometer was composed by a toroidally bent GaAs crystal and a Si plane crystal in dispersionless setup at 45°, working as polarizer, to distinguish contribution to the line braodening coming from other mechanisms.
We observe an increasing broadening of the linewidth in dependence of the intensity but no differences between polarized and non‐polarized spectra, probably because of a too low spatial resolution. A linewidth increase was measured to be 30%. We are working to determine the role of mechanisms other than the Zeeman effect in the measurements. Possible mechanisms causing line broadening, i.e. Stark effect, satellite lines, are discussed.
If the Zeeman effect was the main cause for the measured line broadening, a magnetic field of 5000 tesla would be expected.
