Molecular beam time-of-flight measurements in a nearly freejet expansion of high temperature gas produced by a shock tube

This paper studies translation relaxation in a nearly freejet expansion from a very high temperature source using a shock heated gas as a source. It is shown that Toennies and Winkelmann's theoretical relation can almost be applied to the expansion flow from the high temperature source up to 10,000 K for argon. This paper presents a comparison between the measured effective source temperature and the theoretical source temperature which was calculated by the measured incident shock Mach number. Larger values of speed ratios which follow the theoretical relation could be expected for larger values of lambda (greater than 0.05), if one chose a proper arrangement of the experimental set up to perform an ideal skimming