Published online by Cambridge University Press: 12 April 2016
The technique for absolute calibration using the branching ratio of two transitions which have a common upper level but widely separated energies has been employed and described by Griffin and McWhirter (1961).
Using the plasma produced by irradiation of a carbon target with a 1 GW, 6 nsec duration, neodymium laser pulse, we have been able to calibrate a grazing incidence spectrograph at the wavelength (25.83 Å) of the 7–1 transition in C VI by direct comparison with the intensity of the 7–6 (3434 Å) transition emitted from the same ions in the plasma. The spectrum from a similar carbon plasma has been described by Boland et al. (1968) and in several ways is ideal for this type of measurement.