This effort will complete the work of the original Phase II project within the remaining budget. The effort will concentrate on the optimization of a non-intrusive ignition system. The process of remote ignition of high pressure gases is influenced by turbulence, optics obfuscation, focal point length, and laser beam quality and power. It is the intent of this proposal to study these effects further using a laser diagnostics facility already available. Several new techniques will be studied to improve the remote ignition process. One involves using a target inside the chamber for the laser beam energy to concentrate on. This may improve the repeatability of the process over free space focusing. The laser and optics remain safely outside the chamber. In addition, the laser beam will be moved from the chamber centerline, to the chamber side wall. In this untried scenario, the laser is still focused into the axial center of the chamber, but has a much shorter beam path. This technique will used with and without the aforementioned targets. Finally the project will address techniques to prevent sapphire window fogging such as heating the window and/or additional coating techniques.
