Laserspektroskopie hochgeladener Ionen an der Heidelberger Elektronenstrahl-Ionenfalle

This works demonstrates for the first time resonant laser excitation of a forbidden transition n highly charged ions produced and stored in an electron beam ion trap (EBIT) by irectly monitoring the fluorescence photons. The M1 transition 1s22s22p2 2P3/2-2P3/1 of oronlike Ar13+ was excited by means of a tunable, pulsed dye laser. By monitoring the aser-induced fluorescence in dependence of the laser frequency, the transition wavelength as determined to be 441.25575(17) nm. Furthermore, by applying evaporative cooling, the emperature of the ions was considerably reduced, thus increasing the resolving power to lambda/delta lambda = 15000. Thus the Zeeman splitting of the transition due to the magnetic field in the EBIT was resolved. The inferred g factors for the 2P1/2 and 2P3/2 levels are in excellent agreement with earlier experiments. Additionally, the application of laser spectroscopy allowed for the first time investigations of the plasma dynamics ions, stored magnetically in an EBIT over a period extending several seconds. The accuracy achieved in this first investigation is equal to that of the best wavelength measurements in highly charged ions. This new method however opens a path to much higher accuracies up to determining new optical frequency standards based on forbidden transitions in highly charged ions, which are by orders of magnitude more insensitive to external fields and perturbations than transitions in atoms and low-charged ions