Absolute Measurement of Partial Pressures in the Medium Vacuum Region Using Raman Scattering of Laser Light

The possibility of using Raman scattering as a method of partial pressure m6asurements for Raman-active molecular gases has been investigated in the mediuln vacuum region(10-1-10-2 Pa). The second harmonic beam from a YAG laser having an output energy of O.5J/pulse and a repetition rate of 10Hz was used as the light source. Raman scattering experiments using nitrogen(N2)ahd oxygen(02)gases in air showed that signals from N2 were linear against the N2 partial pressure in the range of 2-103 Pa with an error of less than 10%,