HIGH-PRECISION MEASUREMENT OF THE MAGNETIC-DIPOLE DECAY-RATE OF METASTABLE HELIUM-LIKE CARBON-IONS IN A STORAGE-RING

The radiative decay rate of C4+ ions in the metastable 1s2s3S1 state has been measured at the ion storage ring TSR in Heidelberg, observing the time dependence of the dielectronic recombination rate on resonances characteristic for this metastable state. The very accurate result of 48.57+/-0.11 s-1 allows us to distinguish between different theoretical approaches. Our result is in excellent agreement with a calculation of the magnetic-dipole decay rate using nonrelativistic radial wave functions for the heliumlike carbon ion.