The relativistic recoil effect has been the object of experimental investigations using highly charged ions at the Heidelberg electron beam ion trap. Its scaling with the nuclear charge Z boosts its contribution to a measurable level in the magnetic-dipole (M1) transitions of B- and Be-like Ar ions. The isotope shifts of 36Ar versus 40Ar have been detected with sub-ppm accuracy, and the recoil effect contribution was extracted from the 1s22s22p 2P1/2-2P3/2 transition in Ar13+ and the 1s22s2p 3P1-3P2 transition in Ar14+. The experimental isotope shifts of 0.00123(6) nm (Ar13+) and 0.00120(10) nm (Ar14+) are in agreement with our present predictions of 0.00123(5) nm (Ar13+) and 0.00122(5) nm (Ar14+) based on the total relativistic recoil operator, confirming that a thorough understanding of correlated relativistic electron dynamics is necessary even in a region of intermediate nuclear charges.



Keywords and Phrases

Argon; Beryllium; Boron; Electron Beams; Isotopes; Magnetic Properties; Relativity; Electron Dynamics; Magnetic-dipole (M1) Transitions; Recoil Effects; Relativistic Recoil Operators; Ions

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Document Type

Article - Journal

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Final Version

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© 2006 American Physical Society (APS), All rights reserved.

Publication Date

01 Sep 2006

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Physics Commons