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Full-Text Articles in Physics

Observation And Identification Of Metastable Excited States In Ultrafast Laser-Ionized Pyridine, David B. Foote, Timothy D. Scarborough, Cornelis J. Uiterwaal Jan 2012

Observation And Identification Of Metastable Excited States In Ultrafast Laser-Ionized Pyridine, David B. Foote, Timothy D. Scarborough, Cornelis J. Uiterwaal

C.J.G.J. Uiterwaal Publications

We report on the fragmentation of ionized pyridine (C5H5N) molecules by focused 50 fs, 800 nm laser pulses. Such ionization produces several metastable ionic states that fragment within the field-free drift region of a reflectron- type time of flight mass spectrometer, with one particular metastable dissociation being the leading fragmentation process. Because the time of flight is no longer dependent in a simple way on the mass of the ion, the metastable decay is manifested as an unfocused peak on the mass spectrum that appears at a time of flight not corresponding to an integer mass. …


In Situ Measurement Of Three-Dimensional Ion Densities In Focused Femtosecond Pulses, James Strohaber, Cornelis J. Uiterwaal Jan 2008

In Situ Measurement Of Three-Dimensional Ion Densities In Focused Femtosecond Pulses, James Strohaber, Cornelis J. Uiterwaal

Department of Physics and Astronomy: Dissertations, Theses, and Student Research

We image spatial distribution of xenon ions in the focus of a laser beam of ultrashort, intense pulses in all three dimensions, with a resolution of three by twelve microns in the two transverse directions. This allows for studying ionization processes without spatially averaging ion yields. Our in situ ion imaging is also useful to analyze focal intensity profiles and to investigate the transverse modal purity of tightly focused beams of complex light. As an example, the intensity profile of a Hermite-Gaussian beam mode HG recorded with ions is found to be in good agreement with optical images.