Emission und Schwingungsverteilung der 1. neg. Gruppe und der 2. pos. Gruppe in einem Stickstoffplasma

Abstract

The intensity of the first negative system ofN2+ (B2Σu+-X2Σg+ and of the second positive system ofN2(C3Πu-B3Πg) was observed in the discharge and in the afterglow as function of discharge current. An a. c. discharge in pure nitrogen was used at pressures of about 5 torr. The intensity of the first negative system ofN2+ — in the discharge and in the afterglow — rises to a maximum and decreases with further increase of the discharge current. The afterglow intensity of the second positive system ofN2 shows a maximum too. In the discharge, however, the intensity of the second positive system ofN2 increases with increasing discharge current. The relative population of the vibrational levelsNv′=i/Nv′=0 (i=1,2,3,4) of theB2Σu+ state ofN2+, in the discharge and in the afterglow, increases with increasing discharge current, while the relative population of the vibrational levelsNv′=i/Nv′=0 (i=1, 2, 3, 4) of theC3Πu state ofN2 reaches a maximum in the discharge. There seems to be evidence that the first negative system ofN2+ is not excited by electron impact withN2 molecules in ground state under the discharge conditions in question.