NEW METHOD FOR POLARIZATION MEASUREMENTS OF MAGNETIC-FIELDS IN DENSE-PLASMAS

Measurements of magnetic fields based on observations of the Zeeman sp litting w(B) of spectral lines is a virtually impossible task in dense plasmas of powerful Z-pinches where the Stark splitting in the ion mi crofields w(F) is much greater than w(B). In this situation, much bett er diagnostics of magnetic fields can be achieved through polarization difference contours obtained by subtracting profiles of the same spec tral line observed in two orthogonal linear polarizations. In this way the obscuring role of the Stark effect is significantly diminished. I n the present paper it is shown that the most sensitive and accurate m easurements of the magnitude and the direction of the magnetic field i n a dense plasma tan be conducted employing central Stark components o f hydrogen or hydrogen-like spectral lines. The polarization contour o f a central Stark component turned out to be much more sensitive to th e magnetic field than the polarization contour of a lateral component of the same line, namely by a factor of (w(F)/w(B))(3) much greater th an 1. This constitutes a drastic enhancement of the previously suggest ed method that had used the polarization contour of a lateral Stark co mponent because in dense plasmas a typical value of the above factor i s (w(F)/w(B))(3) greater than or equal to 10(3). The new method can al so be used for laser fusion plasmas and for some astrophysical objects such as magnetic white dwarfs.