We discuss new methods of measuring and interpreting the forbidden-to-intercombination line ratios of helium-like triplets in the X-ray spectra of O-type stars , including accounting for the spatial distribution of the X-ray emitting plasma and using the detailed photospheric UV spectrum .
Measurements are made for four O stars using archival Chandra HETGS data .
We assume an X-ray emitting plasma spatially distributed in the wind above some minimum radius R _ { 0 } .
We find minimum radii of formation typically in the range of 1.25 < R _ { 0 } / R _ { * } < 1.67 , which is consistent with results obtained independently from line profile fits .
We find no evidence for anomalously low f / i ratios and we do not require the existence of X-ray emitting plasmas at radii that are too small to generate sufficiently strong shocks .