Lamb shift and the lifetime of the 2 /sup 2/S/sub 1/2/ state of hydrogenlike argon (Z = 18)

Journal Article · Sat Oct 01 04:00:00 EDT 1983 · Phys. Rev. A; (United States)

DOI:https://doi.org/10.1103/PhysRevA.28.2001· OSTI ID:5388711

Gould, H; Marrus, R

We report a measurement of the Lamb shift in hydrogenlike argon based on the electric-field-quenching method, and a measurement of the unperturbed lifetime of the 2 /sup 2/S/sub 1/2/ state. We find the lifetime of the unperturbed 2 /sup 2/S/sub 1/2/ state to be 3.487(0.036) ns in agreement with the theoretical value of 3.497 ns. This is the first measurement of the 2 /sup 2/S/sub 1/2/ state lifetime of sufficient accuracy to observe the contribution to the total decay rate of the single-photon magnetic dipole decay. Our measured value of the Lamb shift is deltaE(2 /sup 2/S/sub 1/2/-2 /sup 2/P/sub 1/2/) = 37.89(0.38) THz, lower than, but in agreement with, Mohr's value of 38.25(0.025) THz, and 2.7 standard deviations below Erickson's value of 39.01(0.16) THz. Both the quenched and natural lifetimes were measured by the beam-foil time-of-flight technique. In this paper we emphasize the treatment of the systematic effects in the beam-foil time-of-flight method including cascades from higher excited states, interference from the spectra of heliumlike ions, collisions in the residual gas, and perturbations from a highly excited extra electron, as well as systematic effects more unique to electric field quenching.

• Research Organization: Materials and Molecular Research Division, Building 71-259, Lawrence Berkeley Laboratory, University of California at Berkeley, Berkeley, California 94720
• OSTI ID: 5388711
• Journal Information: Phys. Rev. A; (United States), Journal Name: Phys. Rev. A; (United States) Vol. 28:4; ISSN PLRAA
• Country of Publication: United States
• Language: English

Related Subjects

640302* -- Atomic
Molecular & Chemical Physics-- Atomic & Molecular Properties & Theory
74 ATOMIC AND MOLECULAR PHYSICS
ARGON IONS
ATOMS
CHARGED PARTICLES
ELECTRIC FIELDS
ENERGY LEVELS
ION SPECTROSCOPY
IONS
ISOELECTRONIC ATOMS
LAMB SHIFT
LIFETIME
MULTICHARGED IONS
QUENCHING
RADIATIVE DECAY
S STATES
SPECTRAL SHIFT
SPECTROSCOPY
TIME-OF-FLIGHT METHOD