Journal article

Publication year: 1999

Pages: 1279-1296

Journal: Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences

Volume number: 357

Issue number: 1755

ISSN: 1364-503X

eISSN: 1471-2962

DOI Link: https://doi.org/10.1098/rsta.1999.0374

Publisher: The Royal Society

Abstract: 
Experiments with merged beams of electrons and ions stored in accelerator rings have provided a wealth of new data on electron-ion collision processes. The development towards lower and lower temperatures of electron beams and the availability of brilliant beams of ions up to the highest charge states has opened up a precision atomic spectroscopy through the observation of resonances. The available technology also provides unique new access to very low electron-ion collision energies. There, typically below a few millielectronvolts, an unexpected enhancement is observed in the recombination of atomic ions with electrons. For U28+ ions, where such enhancement was seen for the first time, the measured rate coefficient is roughly a factor of 200 higher than expectation for radiative recombination. The experimental spectrum can be simulated by assuming dielectronic recombination (DR) resonances at very low energies. However, recombination enhancements are also observed with completely stripped ions where no DR resonances can occur. Systematic studies of dependences of the new phenomenon on ion charge state, electron density and temperature, and on external electromagnetic fields are being carried out. So far, however, a satisfactory understanding is still missing.

Harvard Citation style: Müller, A. (1999) New light on electron-ion collisions from heavy-ion storage ring experiments, Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences, 357(1755), pp. 1279-1296. https://doi.org/10.1098/rsta.1999.0374

APA Citation style: Müller, A. (1999). New light on electron-ion collisions from heavy-ion storage ring experiments. Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences. 357(1755), 1279-1296. https://doi.org/10.1098/rsta.1999.0374