Abstract

When fast, foil-excited ions are used as a light source, the resulting spectral lines are Doppler broadened because the radiating particles are moving and the spectrograph has a finite acceptance angle. An exact expression has been obtained for the line profile produced by a stigmatic spectrograph without vignetting. For β² < <1, the irradiance is $I(\mathrm{\lambda })\sim {\{\frac{1}{4}{\theta }^2-{[({\mathrm{\lambda }}_0-\mathrm{\lambda })/\beta {\mathrm{\lambda }}_0]}^2\}}^{\frac{1}{2}}$ when the square root is real, and zero otherwise. Theta is the spectrograph’s acceptance angle. The line width at half maximum is Δλ∼0.866 θβλ₀. Vignetting causes the line shape to deviate from the theoretical profile. For a Meinel-type spectrograph, this effect can give doubled line images.

© 1967 Optical Society of America

Analysis of Absorption Profiles of Autoionizing Lines*

Bruce W. Shore
J. Opt. Soc. Am. 57(7) 881-884 (1967)

Analysis of the He ii 4686-Å (n = 4 to n = 3) Line Complex Excited in an Atomic-Beam Light Source*

Harold P. Larson and Robert W. Stanley
J. Opt. Soc. Am. 57(12) 1439-1448 (1967)

Spectral-line profiles and wavelength measurements using the beam–foil light source*

Ming-Wen Chang and William S. Bickel
J. Opt. Soc. Am. 65(11) 1376-1378 (1975)

Solar Hydrogen Lyman-Alpha-Profile Spectrograph

E. C. Bruner and W. A. Rense
J. Opt. Soc. Am. 57(6) 709-715 (1967)

Doppler Shift in a Plasma*

Bruno Manz
J. Opt. Soc. Am. 57(12) 1543-1550 (1967)