Temperature-dependent quenching of UV fluorescence of N2

The detection of fluorescence radiation produced in the atmosphere by the extensive air showers (EAS) generated by the interaction of incoming ultra high energy cosmic rays (UHECR) with the air molecules, is a technique that is being used by several experiments like Hires and Auger. This emission results from the radiative de-excitation of the N2C3ΠuN2C3Πu and N2+B2Σu+ molecular states (2P and 1N systems, respectively) that can also be deactivated by two body collisions with molecules in their ground states. The efficiency of this electronic quenching depends on the nature of the quencher, the gas density and the gas temperature.In this work, an analysis of the quenching mechanisms is presented with particular emphasis on their temperature dependence. The quenching rate constant for 2P(0,0) band is found to decrease with increasing temperature. All data were corrected for geometrical factors and for the temperature dependence of the response of the optical system elements.