Determination of the 1s2ℓ2ℓ′ state production ratios 4Po/2P, 2D/2P and 2P+/2P− from fast (1s2, 1s2s3S) mixed-state He-like ion beams in collisions with H2 targets. (9th November 2016)

• Record Type: Journal Article
• Authors: Benis, E P; Zouros, T J M
• Is Part Of: Journal of physics. Volume 49:Number 23(2016:Dec. 01)
• Publication Date: 2016-11-09
• Subjects: non-statistical population -- electron capture -- cascade feeding -- metastable states -- effective solid angle -- zero-degree Auger projectile spectroscopy -- transfer excitation; 29.27.Fh -- 32.70.Fw -- 34.70+e -- 34.50.Fa; Atoms -- Periodicals; Molecules -- Periodicals; Optics -- Periodicals; Nuclear physics -- Periodicals; 539.6
• DOI: 10.1088/0953-4075/49/23/235202
• Languages: English
• ISSNs: 0953-4075

Abstract

Abstract: New results are presented on the ratio R m = σ T 2 p ( 4 P ) / σ T 2 p ( 2 P ) concerning the production cross sections of Li-like 1 s 2 s 2 p quartet and doublet P states formed in energetic ion–atom collisions by single 2 p electron transfer to the metastable 1 s 2 s 3 S component of the He-like ion beam. Spin statistics predict a value of R m = 2 independent of the collision system in disagreement with most reported measurements of R m ≃ 1 – 9 . A new experimental approach is presented for the evaluation of R m having some practical advantages over earlier approaches. It also allows for the determination of the separate contributions of ground- and metastable-state beam components to the measured spectra. Applying our technique to zero-degree Auger projectile spectra from 4.5 MeV B 3 + (Benis et al 2002 Phys. Rev. A65 064701 ) and 25.3 MeV F 7 + (Zamkov et al 2002 Phys. Rev. A65 062706 ) mixed state ( 1 s 2 1 S, 1 s 2 s 3 S ) He-like ion collisions with H2 targets, we report new values of R m = 3.5 ± 0.4 for boron and R m = 1.8 ± 0.3 for fluorine. In addition, the ratios of 2 D / 2 P and 2 P + / 2 P − populations from either the metastable and/or ground state beam component, also relevant to this analysis, are evaluated and compared to previously reported results for carbon collisions on helium (Strohschein et al 2008 Phys. Rev. A77 022706 ) including a critical comparison to theory.