Precision measurement of the 1s2p P-3(2)-P-3(1) fine structure interval inheliumlike fluorine

Using Doppler-tuned fast-beam laser spectroscopy with co- and counterpropag ating beams we have measured the three hyperfine components of the 1s2p(3)P (2-)(3)P(1) fine structure interval in F-19(7+) Our result for the centroid is 957.6679(10) cm(-1). Allowing for the hyperfine interaction the "pure" fine structure interval is determined to be 957.8730(12) cm(-1). This resul t tests O(alpha(7)m(e)c(2)) quantum electrodynamic corrections to high prec ision calculations which will be used to obtain a new value for the fine st ructure constant from the fine structure of helium. [S0031-9007(99)09157-7] .