Experimental investigations on rotation–vibration energy transfer in H2-N2 collisions

Abstract

Abstract We investigated the rotational-vibrational impact energy transfer processes in a H2–N2 gas mixture system. The stimulated Raman pumping technique was used to excite H2 molecules to the (1,7) high rotational states. The population of the H2(1,7) level was verified by the coherent anti-Stokes Raman (CARS) spectra, the total pressure of the mixture was maintained at 500 Torr, and nitrogen with different molar ratios was filled in the sample cell. The collisional deactivation rate coefficients of the excited state H2(1,7) with H2 and N2 were obtained by fitting the experimental data with the Stern–Volmer equation. The multi-quantum near-resonant rotational relaxation process of H2(1, 7) colliding with N2 was confirmed by the time-resolved CARS profile measurements of H2(v=1, J=7, 5, 3) after the excitation of H2(1, 7).