Occupation of fine-structure states in electron capture and transport

Marek Seliger , Carlos Reinold , Tatsuya Minami , David R. Schultz , Shuhei Yoshida , Joachim Burgdörfer , Emily Lamour (1) , Jean Pierre Rozet (1) , Dominique Vernhet (1)

1 INSP - Institut des Nanosciences de Paris

We study the population of the fine-structure states in excited-state manifolds of hydrogenic Ar17+ ions resulting from charge transfer in collisions of 13.6 MeV/amu Ar18+ ions with thin carbon foils or CH4 and N2 gases. Experimental information on excited states populations is determined by x-ray spectroscopy of individual fine-structure components of the Lyman series allowing for sensitive probes of relativistic effects during the primary charge transfer and the subsequent transport. We show that the ratio of the populations of the 2p1/2 and 2p3/2 states provides clear evidence for spin dependent relativistic effects at moderately relativistic speeds.

Mots clés: argon; atom-molecule collisions; atom-surface impact; electron capture; electron transport theory; excited states; fine structure; positive ions; relativistic corrections; X-ray spectra

Domaines: Physique Atomique [physics.atom-ph]

Marek Seliger, Carlos Reinold, Tatsuya Minami, David R. Schultz, Shuhei Yoshida, et al.. Occupation of fine-structure states in electron capture and transport. Physical Review A : Atomic, molecular, and optical physics [1990-2015], 2008, 77 (4), 042713, 5p. ⟨10.1103/PhysRevA.77.042713⟩. ⟨hal-00347104⟩