Measurement and interpretation of the polarization of the x-ray line emission of heliumlike FeXXV excited by an electron beam

Journal Article · Sat Jun 01 00:00:00 EDT 1996 · Physical Review A

DOI:https://doi.org/10.1103/PhysRevA.53.3974· OSTI ID:284319

Beiersdorfer, P; Vogel, D A; Reed, K J; Decaux, V; Scofield, J H; Widmann, K ^[1]; Hoelzer, G; Foerster, E; Wehrhan, O ^[2]; Savin, D W ^[3]; Schweikhard, L ^[4]

---

1. Department of Physics and Space Technology, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)
2. Max-Planck Arbeitsgruppe Roentgenoptik, Friedrich-Schiller-Universitaet, D-07743 Jena (Federal Republic of Germany)
3. Space Science Laboratory, University of California, Berkeley, California 94720 (United States)
4. Institut fuer Physik, Johannes Gutenberg Universitaet, D-55099 Mainz (Federal Republic of Germany)

The linear polarization of the 1{ital s}2{ital p}{sup 1}{ital P}{sub 1}{r_arrow}1{ital s}{sup 2}{sup 1}{ital S}{sub 0} resonance line, the 1{ital s}2{ital p}{sup 3}{ital P}{sub 1,2}{r_arrow}1{ital s}{sup 2}{sup 1}{ital S}{sub 0} intercombination lines, and the 1{ital s}2{ital s}{sup 3}{ital S}{sub 1}{r_arrow}1{ital s}{sup 2}{sup 1}{ital S}{sub 0} forbidden line was measured in heliumlike FeXXV excited near threshold by a monoenergetic electron beam. The measurement was carried out with a high-resolution x-ray spectrometer employing a set of two analyzing crystals that acted as polarizers by selectively reflecting the individual polarization components. A value of +0.56{sup +0.17}{sub {minus}0.08} was determined for the polarization of the {sup 1}{ital P}{sub 1} line, {minus}0.53{sup +0.05}{sub {minus}0.02} for the {sup 3}{ital P}{sub 2} line, {minus}0.22{sup +0.05}{sub {minus}0.02} for the {sup 3}{ital P}{sub 1} line, and {minus}0.076{sup +0.007}{sub {minus}0.007} for the {sup 3}{ital S}{sub 1} line. The measurements were compared with results from a relativistic distorted-wave calculation, which was carried out for a number of mid-{ital Z} heliumlike ions (Mg{sup 10+}{endash}Kr{sup 34+}), and good agreement was found. By contrast, disagreement was noted with predictions based on Coulomb-Born calculations, allowing us to distinguish between theoretical approaches. {copyright} {ital 1996 The American Physical Society.}

• Research Organization: Lawrence Livermore National Laboratory
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 284319
• Journal Information: Physical Review A, Journal Name: Physical Review A Journal Issue: 6 Vol. 53; ISSN 1050-2947; ISSN PLRAAN
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ELECTRON-ION COLLISIONS
IRON IONS
MULTICHARGED IONS
POLARIZATION
POLARIZED BEAMS
RESONANCE
S STATES
X-RAY SPECTRA