MINIATURIZED FIBER-PULLING APPARATUS FOR PRODUCING SINGLE-CRYSTAL-CORE GLASS FIBERS IN MICROGRAVITY

GRAVITY ADVERSELY AFFECTS GLASS FIBER PULLING BY SEVERELY RESTRICTING FEASIBLE GLASS VISCOSITIES DURING PULLING BECAUSE OF SAGGING. THIS EFFECT IS ESPECIALLY TROUBLESOME FOR THE PULLING OR SINGLE-CRYSTAL-CORE GLASS FIBERS, WHERE THE REQUIREMENT OF GLASS/CRYSTAL THERMAL EXPANSION MATCHING VS. CORE MELTING POINT DICTATES PULLING AT GLASS VISCOSITIES THAT ARE TOO LOW TO BE FEASIBLE AT 1 G. WE THEREFORE PROPOSE TO PRODUCE CRYSTAL-CORE GLASS FIBERS FOR VARIOUS APPLICATIONS IN MICROGRAVITY. AS A MEANS TOWARD THIS GOAL, WE PROPOSE TO DEVELOP A MINIATURIZED FIBER-PULLING APPARATUS FOR SPACEFLIGHT OPERATION; THIS IS THE PRINCIPAL OBJECTIVE OF PHASE I. THIS APPARATUS WILL EMBODY SEVERAL NOVEL DESIGN FEATURES FOR COMPACTNESS, EASY FIBER REMOVAL AND STORAGE, AND AUTOMATION. DURING PHASE II, WE WILL DEVELOP THE GROUND-ENGINEERING MODEL OF THE APPARATUS AND DEFINE AND DEVELOP CRYSTAL-CORE FIBER EXPERIMENTS FOR PERFORMANCE IN SPACEFLIGHT MISSIONS DURING PHASE III.