  Bose-Einstein correlations in pairs of charged kaons produced in a sample of
3.9 million hadronic Z0 decays have been measured with the OPAL experiment at
LEP. Charged kaons were identified in the central tracking detector using their
specific energy loss in the drift chamber gas. The correlation function was
studied in two-jet events using a double ratio, formed by the number of
like-sign pairs normalised by a reference sample in the data, divided by the
same ratio in a Monte Carlo simulation. The enhancement at small values of the
four-momentum difference of the pair was parametrised using a Gaussian
function. The parameters of the Bose-Einstein correlations were measured to be
lambda = 0.82+-0.22(+0.17,-0.12) for the strength and R0 =
0.56+-0.08(+0.08,-0.06) fm for the kaon source radius, where the first errors
are statistical and the second systematic. Corrections for final-state
interactions are discussed.
