Abstract
An ultrarapid scanning spectrometer has been constructed that records spectra at a constant angle of diffraction. The spectral scanning is accomplished by the rotation of a high-speed rotating mirror (7.6 cm diam) that causes a collimated light beam to sweep across a plane grating, changing the angle of incidence. The full-aperture scanning range depends upon the over-all grating width, upon the grating spacing, and upon the orientation of the grating with respect to the high-speed mirror. For example, a 12.5-cm, 1200-lines/mm grating gives a scanning range of ~2000 Å on each of two separate detector systems, or a total range of 4000 Å that can be centered at any wavelength between 4000 Å and 8000 Å. This grating provides a theoretical resolving power of ~85,000 in the first order, a reciprocal dispersion of 17.5 Å/mm at f/5, and a spectral scan speed of 115 Å/μsec at 1100 rps. This spectrometer has been used to record, simultaneously, Stark-broadened Hα and Hβ emission line profiles from a transient plasma generated in the impulse tube. Electron densities calculated from the half-width of the Hβ profiles are in good agreement with values obtained by fitting the line wings of the self-absorbed Hα profiles to the theoretical profiles of Griem, Kolb, and Shen.
© 1966 Optical Society of America
Full Article | PDF ArticleMore Like This
R. A. Hill
Appl. Opt. 7(11) 2184-2189 (1968)
R. A. Hill
Appl. Opt. 4(12) 1593-1595 (1965)
Charles H. Church and Leonard Gampel
Appl. Opt. 5(2) 241-244 (1966)