Neutral nanocluster chemistry studied by soft x-ray laser single-photon ionization:: Application to soft x-ray optical surface contamination studies:: SimOn and TimOn

Metal oxide clusters are employed in studies to help understand an important, specific, type of surface chemical problem: the contamination of soft x-ray mirrors by carbon deposits. Herein we report nanocluster chemistry studies that are relevant to the use of silicon oxide and titanium oxide capping layers. Systems involving SimOn, and TimOn metal oxide nanoclusters are generated in a pulsed supersonic expansion/ablation source and passed through a reactor containing any reactant desired. The reaction products of these gas phase clusters are ionized using single photon ionization from a desk-top sized 46.9 nm Ne-like Ar laser providing the advantage of little or no fragmentation of desired nanoclusters. The ionized products are analyzed by a time of flight mass spectrometer and experimental results supply useful information related to condensed phase soft x-ray optical surfaces. The results illustrate the great potential of the use of very compact soft x-ray lasers in photochemistry and photophysics studies.