Spectrum of fluorine and sulfur in the range λ320–λ350: the spectrum in the middle panel was recorded with our moderate-resolution LoWEUS spectrograph at the EBIT-I electron beam ion trap at an electron beam energy of 1000 eV. Visually recognized line positions are denoted. The lowest panel of the figure shows a high-resolution spectrum at half the wavelength, obtained using our HIGGS instrument. Strong first-diffraction order lines in this spectrum may appear in second diffraction order in the spectrum in the middle panel. Identified spectral features are labeled by the corresponding spectrum. We note the presence of several (known) O and F lines with wavelengths of 160 to 173 Å, the second diffraction order images (denoted “2”) of which appear in the range of the SDO/AIA λ335 band, but would not affect the observations with SDO/AIA. The approximate band pass function of the SDO/AIA λ335 channel is indicated in the top panel.