Velocity control of ozone beam

In order to obtain an active ozone beam and make full use of ozone oxidation ability, we used laser ablation method. High concentration ozone from an ozone jet generator was solidified on a sapphire substrate and then pulsed KrF laser was irradiated to the solid ozone. Ablated species and their velocity distribution have been investigated using time-of-flight method through a quadrupole mass filter. Ablated species were mainly a mixture of ozone, molecular oxygen and atomic oxygen. As for their velocity distribution, ozone showed a thermal equilibrium, while molecular oxygen showed many slower components. Ablated ozone yields were strongly dependent on laser power and showed a maximal. The ratio of ozone against molecular oxygen in the mixture increased as the substrate temperature became higher, probably because of increase in the purity of the solid ozone on the substrate. Ozone velocity varied from 1500 K to 2500 K depending on the laser power and the substrate temperature, which means that we can supply an ozone beam that has controlled purity and velocity.