Search for 1{ital s}2{ital s}{sup 3}{ital S}{sub 1}{endash}1{ital s}2{ital p}{sup 3}{ital P}{sub 2} decay in U{sup 90+}

Journal Article · Sat Jun 01 04:00:00 EDT 1996 · Physical Review A

DOI:https://doi.org/10.1103/PhysRevA.53.4000· OSTI ID:284320

Beiersdorfer, P; Elliott, S R; Osterheld, A; Stoehlker, T; Autrey, J; Brown, G V; Smith, A J; Widmann, K ^[1]

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1. Department of Physics and Space Technology, Lawrence Livermore National Laboratory, Livermore, California 94550 (United States)

We present high-resolution crystal-spectrometer measurements that cover the wavelength range 3.0{endash}3.2 A containing the electric-dipole-allowed 2{ital s}{sub 1/2}-2{ital p}{sub 3/2} transitions in highly charged uranium ions. Strong features from 2{ital s}{sub 1/2}-2{ital p}{sub 3/2} transitions in lithiumlike, berylliumlike, and boronlike uranium were observed. In addition, a weak feature with intensity just above the level of background fluctuations was observed at the predicted location of the 1{ital s}2{ital s}{sup 3}{ital S}{sub 1}{endash}1{ital s}2{ital p}{sup 3}{ital P}{sub 2} transition in heliumlike U{sup 90+}. The feature was observed in spectra where the intensity of the 2{ital s}{sub 1/2}-2{ital p}{sub 3/2} transition in lithiumlike uranium, and thus the ionization balance, was optimized; it appeared absent in spectra where the average ionization balance was lower. The measured energy of the feature is 4510.05{plus_minus}0.24 eV, which agrees closely with the values predicted for the 1{ital s}2{ital s}{sup 3}{ital S}{sub 1}{endash}1{ital s}2{ital p}{sup 3}{ital P}{sub 2} transition by recent theories. Detailed spectral modeling calculations indicate the possibility that a weak transition in berylliumlike U{sup 88+} is situated within 4 eV of the location of the heliumlike {sup 3}{ital S}{sub 1}-{sup 3}{ital P}{sub 2} transition. This transition connects the level 1{ital s}{sup 2}2{ital p}{sub 1/2}2{ital p}{sub 3/2}{sup 3}{ital p}{sub 1} with the 1{ital s}{sup 2}2{ital s}{sub 1/2}2{ital p}{sub 1/2}{sup 3}{ital P}{sub 0} metastable ground level in berylliumlike uranium. The accuracy with which the energy of the berylliumlike transition can be predicted is insufficient to rule out a blend with the heliumlike {sup 3}{ital S}{sub 1}-{sup 3}{ital P}{sub 2} transition. {copyright} {ital 1996 The American Physical Society.}

• Research Organization: Lawrence Livermore National Laboratory
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 284320
• 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
AMPLITUDES
B-LIKE IONS
BE-LIKE IONS
DECAY
ENERGY-LEVEL TRANSITIONS
HE-LIKE IONS
LI-LIKE IONS
LINE INTENSITY
P STATES
S STATES
URANIUM IONS
X-RAY SPECTRA