Solution to the perturbation of LIF measurements via photodissociation, OH measurement in atmospheric-pressure multihollow DBD

Abstract

This study solves the problem of the invasivity of laser-induced fluorescence (LIF) measurements caused by photodissociation. It is shown with the example of OH LIF that the excess signal caused by laser-induced photodissociation can be distinguished from the true LIF signal of the naturally presented species by its different dependence on the energy of laser pulses. This fact can be further used for the detection of photodissociable species not accessible by the standard LIF. This method is applied to OH radicals in atmospheric-pressure multihollow dielectric barrier discharge plasma ignited in a number of holes. OH radicals are concentrated at the effluents of these holes, but they are able to spread to a distance of 5 mm, meaning that the discharge is suitable for the treatment of distant and rough surfaces.