Measurement of Fe emission spectrum from 170 nm to 600 nm with a coma-free spectrometer

A coma-free superhigh spectral resolution optical spectrometer was successfully designed and constructed for practical application. The spectrometer consisted of 20 subgratings and a 2D BSI-CMOS array detector. The spectra were 20-fold with the physical size of the photoelectron detection along the diffraction direction and extended by a factor of 20 to achieve a spectral resolution of 0.01 nm per pixel without any moving parts. Ultrahigh dense emission lines of a hollow cathode Fe lamp were measured. Based on the data analysis and discussions, among the highly resolved spectral lines of Fe measured with an improved signal-to-noise ratio in the 170-600 nm spectral region, 2451 lines were identified in accordance with the reported ones in the literature; however, more than 1100 lines with lower intensity remained unassigned with an unknown mechanism of their origins. Our experimental data indicated the need to more fundamentally study and explore the spectral data of the Fe atoms with the potential for broad application prospects for Fe-based materials in the future. A coma-free superhigh spectral resolution optical spectrometer was successfully designed and constructed for practical application.