Ultraviolet transitions from the 2 /sup 3/P states of helium-like argon. [E2, 138 MeV, absolute wavelengths, beam--foil excitation, half-life]

Technical Report · Wed Sep 01 00:00:00 EDT 1976

DOI:https://doi.org/10.2172/7137071· OSTI ID:7137071

Davis, W A

This thesis describes the observation of two allowed electric dipole transitions in helium-like argon. The transitions are 2 /sup 3/P/sub 2/--2 /sup 3/S/sub 1/ and 2 /sup 3/P/sub 0/--2 /sup 3/S/sub 1/. These transitions were observed by using a vacuum ultraviolet monochromator to collect photons from decays-in-flight of a beam-foil excited argon ion beam. The ion beam was generated by the Lawrence Berkeley Laboratory heavy ion linear accelerator (SuperHILAC) and had a beam energy of 138 MeV with a charge current of roughly 500 nanoamperes. After initial observation, the lifetimes and absolute wavelengths of these transitions were measured. The results are tau(2 /sup 3/P/sub 2/) = 1.62 +- 0.08 X 10/sup -9/ sec, tau(2 /sup 3/P/sub 0/) = 4.87 +- 0.44 X 10/sup -9/ sec, lambda(2 /sup 3/P/sub 2/--2 /sup 3/S/sub 1/) = 560.2 +- 0.9A, and lambda(2 /sup 3/P/sub 0/--2 /sup 3/S/sub 1/) = 660.7 +- 1.1A. This work has demonstrated the observability of these transitions in high-Z ions using beam-foil excitation. Employing a new grazing-incidence spectrometer this work will be pursued in ions of higher Z. Accuracies of at least one part in a thousand should be attainable and will probe the radiative contributions to these transitions to better than 10 percent in a previously unstudied region.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• DOE Contract Number: W-7405-ENG-48
• OSTI ID: 7137071
• Report Number(s): LBL-5441; TRN: 77-002776
• Resource Relation: Other Information: Thesis
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
ARGON
ENERGY-LEVEL TRANSITIONS
ELECTRIC DIPOLE MOMENTS
HALF-LIFE
MEV RANGE 100-1000
P STATES
PHOTONS
S STATES
ULTRAVIOLET RADIATION
DIPOLE MOMENTS
ELECTRIC MOMENTS
ELECTROMAGNETIC RADIATION
ELEMENTARY PARTICLES
ELEMENTS
ENERGY LEVELS
ENERGY RANGE
MASSLESS PARTICLES
MEV RANGE
NONMETALS
RADIATIONS
RARE GASES
640302* - Atomic
Molecular & Chemical Physics- Atomic & Molecular Properties & Theory