2019-05-20T05:13:49Z
http://digital.csic.es/dspace-oai/request
oai:digital.csic.es:10261/2798
2016-02-16T02:26:55Z
com_10261_135
com_10261_4
col_10261_388
00925njm 22002777a 4500
dc
Fonfría, José Pablo
author
Ramos, Ángel
author
Thibault, Franck
author
Tejeda, Guzmán
author
Fernández Sánchez, José María
author
Montero, Salvador
author
2007-10-03
Theory and experiment are combined in a novel approach aimed at establishing a set of two-body state-to-state rates for elementary processes ij->lm in low temperature N2:N2 collisions involving the rotational states i, j, l, m. First, a set of 148 collision cross sections is calculated as a function of the collision energy at the converged close-coupled level via the MOLSCAT code, using a recent potential energy surface for N2–N2. Then, the corresponding rates for the range of 2<T<50 K are derived from the cross sections. The link between theory and experiment, aimed at assessing the calculated rates, is a master equation which accounts for the time evolution of rotational populations in a reference volume of gas in terms of the collision rates. In the experiment, the evolution of rotational populations is measured by Raman spectroscopy in a tiny reference volume 2E-3 mm3 of N2 traveling along the axis of a supersonic jet. The calculated collisional rates are assessed experimentally in the range of 4<T<35 K by means of the master equation, and then are scaled by averaging over a large set of experimental data. The scaled rates account accurately for the evolution of the rotational populations measured in a wide range of conditions. Accuracy of 10%
is estimated for the main scaled rates.
The Journal Of Chemical Physics 127, 134305 (2007)
0021-9606
http://hdl.handle.net/10261/2798
10.1063/1.2784255
nitrogen
collisions
low temperature
Inelastic collisions in molecular nitrogen at low temperature (2<T<50 K)