Efficient production of vibrationally excited NO using a pulsed molecular beam discharge source

An efficient way of producing vibrationally excited, but rotationally cold NO molecules is described. A dc-discharge is incorporated into a piezoelectric pulsed molecular beam valve of the Gerlich design. Efficiencies larger than 10% are achieved for the production of vibrationally excited NO(v′′=1) characterized by a rotational temperature of 4 K. At lower backing pressures, a population ratio NO(v′′=1)/NO(v′′=0)=0.5 is found with rotational temperatures around 30 K. Population of NO in higher vibrational states, e.g. v′′=2, is generated with smaller but still significant density. Even highly vibrationally excited NO molecules with 7⩽v′′⩽19 have been detected.