Temperature measurements in shock tubes; transition probabilities for argon lines

The transition probabilities of 13 argon (Ar I) spectrum lines between 4159 and 7635 A have been determined from their emission intensities from shock-heated argon. The equilibrium temperature was calculated from the measured speed of the incident shock in a detonating-driver type shock tube. Corrections for self-absorption in the stronger red lines were made by using theoretical values for the Stark line width. Results are compared with others obtained from measurement on arc plasmas or from theoretical calculations, and the accuracy of these values is discussed. The transition probabilities given should enable temperatures in the range 6000 to 15000 °K in argon to be determined from the ratio of line intensities.