A Novel Method to Determine Magnetic Fields in Low-density Plasma Facilitated Through Accidental Degeneracy of Quantum States in Fe9+
We propose a new method to determine magnetic fields, by using the magnetic-field-induced electric dipole transition 3p(4) 3d D-4(7/2) -> 3p(5) P-3/2 in Fe9+ ions. This ion has a high abundance in astrophysical plasma and is therefore well suited for direct measurements of even rather weak fields in, e.g., solar flares. This transition is induced by an external magnetic field and its rate is propo
