STUDY OF THE ZEEMAN SPLIT IN HYDROGEN IN MG MAGNETIC FIELDS*

A Zeeman effect is used for investigation of magnetic fields in astrophysical and laboratory plasmas. Magnetic fields in the atmosphere of magnetic white dwarf stars are in the range of 1 - 100 MG. A quadratic Zeeman effect may contribute to the line split in this range of magnetic fields.

We studied absorption hydrogen Balmer lines in magnetic fields relevant to white dwarf stars. A 1 MA pulse power machine at the University of Nevada, Reno produces magnetic fields up to 4 MG. The magnetic field was generated on the surface of rod loads, 0.8-1 mm in diameter. A droplet of CH oil on the center of the rod load was a source of hydrogen. Oil was irradiated by emission from the surface of the rod with a temperature of 0.5-0.6 eV. Optical spectra of hydrogen were recorded using a spectrometer with two gratings, 1200 l/mm and 2400l/mm and an ICCD sensor. A Zeeman splitting of the H-alpha line was seen at the central wavelength of 656 nm. The value of the Zeeman splitting indicated the magnetic fields of 2-3 MG. These values were in agreement with data from Faraday rotation diagnostics and B-dot sensors. A shift of the central component of the Zeeman triplet will be used for investigation of the quadratic effect.