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The capture of polarized electrons by H-like ions provides a method for polarizing the nuclei of He-like heavy ions with zero total electron angular momentum in storage rings for high-energy ions. A detailed analysis for gj'Eu ions with nuclear spin / = 5/2 predicts a nuclear polarization degree of about 47% already after one passage through a target containing 100% polarized electrons. Almost 50% of the polarized He-like ions are predicted to be in states with zero total electron angular momentum. Such ions were recently considered as the most promising candidates in experiments at storage rings for the search for violations of the fundamental symmetries and for a nuclear and an electron electric dipole moment.During the last decades, experiments with spin-polarized particles became of primary importance in low-energy fun damental physics. Except for highly charged ions (HCI), the techniques for polarizing beams of electrons, protons, and muons have been well developed by now. However, during the last years several experiments using just polar ized HCI for tests of fundamental symmetries like parity nonconservation (PNC) and for the search for a nuclear and an electron electric dipole moment (EDM) have been proposed ([1-5]).Up to now, only a theoretical investigation of a method for polarizing the nuclei of HCI by selective laser excitation of the hyperfine sublevels of H-like ions has been performed ([5]). However, in all cases considered, the typical beam velocity of 0.3 c and 106 revolutions per second around the ring yielded building-up times for an almost 100% degree of polarization much longer than the revolution time around the ring. Already after one revolution, the interaction between the magnetic moment of the ions and the magnetic system needed for ion beam bending and focusing destroys the beam polarization completely and thus a continuous building up of the beam polarization is impossible. In-ring mounting of special insertion devices like Siberian Snakes [6,7], which are special magnets for a controlled rotation of the direction of the polarization of the particles, can partly avoid the loss of polarization. Nevertheless, even with the use of Siberian Snakes the conditions for the control of many of the magnetic fields in the ring regarding strength, direction, and time dependence necessary to avoid the depolarizing effects remain extremely restrictive.Another important problem is the monitoring of the degree of beam polarization, which is of great importance for the quantitative analysis of the experimental results. A promising proposal seems to be the observation of the linear polarization of x rays in the process of radiative recombination (RR) between ions and electrons. This idea was suggested in Ref.[8] and later developed and partly exploited experimentally in Refs. [9][10][11].It is obvious that a strong reduction of the building-up time of the polarization would be an essential improvement for the experiments envisaged. At best, the full beam polarization should be recovered after every re...

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It is demonstrated that the effect of the electric dipole moment of electron and of the P,T-odd electron–nucleus interaction can be well distinguished in the experiments with H-like (or Li-like) highly charged ions in storage rings. These two effects cannot be separated in the experiments with a certain atom or molecule. Possible experiments for the search of P,T-odd effects with H-like ions in storage rings are discussed and the parameters of these experiments (observation time, field control) are estimated.