Shock-tube Mfa5lreme.wts of Tue Vibration-vibration Energy Exchance Probability for the Cü-n_ System

A shock-tube study was carried out to measure the vibration-vibration 10 energy exchange probability, P(N., CO), in N /CO/Ar mixtures. It was determined that at a temperature of about 4U00K, the measured probability, 10 _j P(N0, CO) * 8*10 , aßrees fairlv well with the theoretical prediction of i01 Schwartz, Slawsky, and Herzfeld (SSH), but that with decreasing temperature the measured probability falls considerably below the SSH theorv prediction, i.e., P(N0, CO) = AxlO"" (measured) and P(N0, CO) » 4xl0~ 3 (SSH), 2 oi ^ 01 at 2000K. The experimental results also demonstrate that over the temperature range 2000-A0n0K, argon and nitrogen are about equally efficient as translation-vibration collision partners for vlbrational relaxation of CO, whereas, argon is between 2 and 3 times less efficient than N. for vibrational relaxation of N„ molecules.