Branching fractions were measured for electric dipole transitions from the 5p
upper levels to the 5s levels in neutral krypton atoms. The measurements were
made with a wall-stabilized electric arc and a 2m monochromator for the
spectral lines in the visible, and with a hollow cathode lamp and the NIST
2m-Fourier transform spectrometer for the lines in the near infrared. A
semi-empirical calculation, based on accurately known lifetimes for six upper
levels, was used to calculate lifetimes for which accurate measurements do not
exist. This resulted in a complete set of lifetimes for all 5p levels.
Branching fractions and lifetimes were used to calculate transition rates for
the 5p-5s transitions. The relative uncertainties of the transition rates range
from less than 1% for the strongest lines to about 10% for the weakest lines.
Our data also reveal that most of the previous measurements appear to have been
affected by opacity effects in the light sources.Comment: 18 pages, 6 figures, 5 table
