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A: Fachverband Atomphysik

A 25: Precision Spectroscopy of Atoms and Ions III

A 25.5: Vortrag

Freitag, 12. März 2010, 11:30–11:45, F 107

Exciting and ionizing trapped highly charged ions with electrons and photons in an EBIT — •José R. Crespo López-Urrutia — Max-Planck-Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg

Hot cosmic matter, found in, e. g., around black hole accretion disks, in active galactic nuclei, supernova remnants, and in the warm-hot intergalactic medium can be prepared and studied in the laboratory with electron beam ion traps (EBITs). A fundamental interest arises from the fact that, for bound electrons, quantum electrodynamic (QED) as well as relativistic contributions grow steeply with the fourth power of the nuclear charge, and thus from small perturbations to major effects. Denuding atoms from most of their electrons in a controlled way exposes these magnified effects even better, and allows electronic correlation studies along isoelectronic sequences. In EBITs, highly charged ions (HCI) are produced, and their interactions with nearly monoenergetic electrons, with tunable lasers (both in the visible and soft X-ray region), and with keV photon beams from synchrotrons are used to excite and precisely measure electronic resonances. In particular, novel X-ray free-electron lasers (FLASH, LCLS), and synchrotron radiation (BESSY II) allow to go beyond the current accuracy limits. A report on recent results on few-electron QED, photoionization of HCI, dielectronic and trielectronic recombination processes, and laser spectroscopy of forbidden transitions investigated at the Heidelberg EBIT laboratory will be given.