MEASUREMENT OF THE TRANSVERSE DOPPLER-SHIFT USING A STORED RELATIVISTIC LI-7(+) ION-BEAM

We have performed for the first time precision spectroscopy on a coasting fast Li-7+ ion beam in a storage ring, The ion beam moving with 6.4% speed of light was first electron cooled and then merged with two counter-propagating laser beams acting on two different hyperfine transitions sharing a common upper level (LAMBDA-system). One laser was frequency locked to the a3 127J2 hfs frequency component established as a secondary frequency standard at 514 nm. The second laser was tuned over the LAMBDA-resonance, which was recorded relative to 127J2 hfs components. This experiment is sensitive to the time dilation in fast moving frames and will lead to new limits for the verification of special relatively. The present status of the experiment and perspectives in accuracy are discussed.