Extreme Ultraviolet Spectroscopy of Highly Charged Tungsten for Magnetic Fusion Plasma Diagnostics*

The NIST electron beam ion trap has been used to provide accurate transition wavelengths in the 2-20 nm spectral range for highly charged elements near Z=74 (tungsten).~ Spectra were recorded over a wide range of monoenergetic electron impact energies (2-27 keV), to produce charge states in the range of Q=37-65, corresponding to those expected in thermal plasmas with temperatures up to about 100,000,000 K (such as ITER).~ In addition to W, we also studied several elements with similar mass (Hf, Ta, and Au) in order to reveal isoelectronic trends.~ We have compared the measured spectral distribution of light to synthetic spectra computed using the NOMAD collisional-radiative code using atomic data generated by the FAC code.~