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Spectrum of Th-Ar Hollow Cathode Lamps

NIST Standard Reference Database 161

Last Update to Data Content: August 2017 | Version History  |  Disclaimer | DOI:

Gillian Nave1, Ariel Shlosberg2, Stephen L. Redman1, Craig J. Sansonetti1
1National Institute of Standards and Technology, Gaithersburg, MD 20899, USA
2NIST Summer Undergraduate Research Fellow


This atlas presents observations of the spectra of Th-Ar hollow cathode lamps at currents ranging from 20 mA to 320 mA. The spectra were measured using Fourier transform spectrometers at the National Institute of Standards and Technology (NIST) and Kitt Peak National Observatory (KPNO). The spectra were taken from the measurements of Palmer & Engleman (1983), Engleman, Hinkle, & Wallace (2003), Kerber et al. (2008), and Redman, Nave & Sansonetti (2014) and are fully described in those papers.

In addition to the plots of the spectra, a list of the spectral lines in each region are included that can be used as reference wavelengths for the calibration of high-resolution spectrographs.  Reference wavelengths for over 20 000 lines of Th I, Th II, and Th III, were taken from Redman, Nave & Sansonetti (2014) and are based on Ritz wavelengths derived from optimized energy levels. Spectral lines of Ar I [Whaling et al. (2002), Sansonetti (2007), measured only],  Ar II and Ar III [Whaling et al. (1995)], Ne I [Saloman & Sansonetti (2004)], and Ne II and Ne III [Kramida & Nave (2006)] are also included in the linelist.

Atlas Data

Standard Reference Database 161 | Customer Support | Online: May 2009 | Revised: August 2017


Created July 6, 2009, Updated May 23, 2023