Document Type
Article
Publication Date
10-12-2017
Department 1
Physics
Abstract
We present measurements of ion velocity distributions obtained by laser induced fluorescence (LIF) using a single viewport in an argon plasma. A patent pending design, which we refer to as the confocal fluorescence telescope, combines large objective lenses with a large central obscuration and a spatial filter to achieve high spatial localization along the laser injection direction. Models of the injection and collection optics of the two assemblies are used to provide a theoretical estimate of the spatial localization of the confocal arrangement, which is taken to be the full width at half maximum of the spatial optical response. The new design achieves approximately 1.4 mm localization at a focal length of 148.7 mm, improving on previously published designs by an order of magnitude and approaching the localization achieved by the conventional method. The confocal method, however, does so without requiring a pair of separated, perpendicular optical paths. The confocal technique therefore eases the two window access requirement of the conventional method, extending the application of LIF to experiments where conventional LIF measurements have been impossible or difficult, or where multiple viewports are scarce.
Copyright Note
This is the publisher's version of the work. This publication appears in Gettysburg College's institutional repository by permission of the copyright owner for personal use, not for redistribution.
DOI
10.1063/1.4991637
Version
Version of Record
Recommended Citation
Thompson, Derek S., Miguel F. Henriquez, Earl E. Scime, and Timothy N. Good. "Confocal laser induced fluorescence with comparable spatial localization to the conventional method." Review of Scientific Instruments 88, no. 10 (2017).
Required Publisher's Statement
Original version available online at http://aip.scitation.org/doi/full/10.1063/1.4991637