Isotope and hyperfine splittings for two UV transitions in tungsten I by saturation and polarisation spectroscopy

Isotope shifts and hyperfine splittings in tungsten I have been measured by Doppler-free saturated absorption and polarisation spectroscopy on two UV transitions at 294.44 nm and 294.70 nm. The splittings between the even isotopes (¹⁸²W, ¹⁸⁴W, ¹⁸⁶W) and the splitting between the two strong hyperfine components of ¹⁸³W were measured in a natural isotopic mixture of tungsten introduced into a hollow cathode discharge. In addition, using single isotope ¹⁸³W, the level hyperfine splittings were measured by resolving crossover peaks between the strong and weak hyperfine components. These measured level splittings are compared with those predicted from centre of gravity considerations.