In laboratory cooks pure oxygen was profiled into the circulation line of a batch digester during two periods of the cooking cycle: The first injection occurred during the heating steps for the purpose of in-situ generation of polysulfide. This chip treatment was studied to explore stabilization against alkaline induced carbohydrate peeling and to increase pulp yield. Under optimum conditions small amounts of polysulfide were produced with yield increase of about 0.5% These increases fell below earlier reports suggesting that unknown differences in liquor composition may influence the relative amounts of polysulfide and thiosulfate generated during the oxidation. Consequently, further studies are required to understand the factors that influence the ratios of those two sulfur species.

This document is a final report of the U.S. DOE grant entitled ''Investigation of the Spherical Stellarator Concept'' which supported theoretical and numerical investigation of a novel fusion concept, the ultra-low-aspect-ratio stellarator system called Spherical Stellarator (SS). The research was concentrated on (a) search for principally different types of SS configurations, (b) optimization of SS configurations by varying the parameters of the coil systems, (c) finite beta and finite plasma current (including bootstrap current) equilibria in the SS, and (d) Monte Carlo particle transport simulations for the SS.