Exploratory development of fusion cast calcium fluoride for 1. 06 micrometer pulsed laser optics. Progress report, June 25, 1976--September 25, 1976

Technical Report · Mon Nov 01 04:00:00 EST 1976

DOI:https://doi.org/10.2172/7258592· OSTI ID:7258592

Willingham, C. B.; Newberg, R. T.

This program is an assessment of fusion cast polycrystalline calcium fluoride for optical components of 1.064 micrometer pulsed laser fusion systems. Task areas include casting of essentially stress-free 33 centimeter diameter, 5 centimeter thick ingots, developing surface finishing techniques for optically figured plane and spherical surfaces, and evaluate state-of-the-art antireflection coatings deposited onto the specimens of the cast material. During the first quarter, a new casting furnace was installed in the laboratory and put into operation. Two complete casting runs were made. Temperature profiles taken during the first run demonstrated the existence of unacceptably large radial gradients in the furnace and led to the design and installation of new heating elements prior to the second casting effort. Redesigned heating elements and other furnace modifications decreased the radial gradients by more than a factor of three during the second run, but the ingot was still badly strained. Furnace modifications made before a third run, which is now in progress, appear to have further reduced the gradients. Although the upper portion of the ingot from that second run contained growth defects, there is enough sound material to supply substrates for the antireflection coating task. Casting and post-casting annealing treatment studies are continuing.

• Research Organization: Raytheon Co., Waltham, MA (USA). Research Div.
• OSTI ID: 7258592
• Report Number(s): COO-4029-1
• Country of Publication: United States
• Language: English

Related Subjects

70 PLASMA PHYSICS AND FUSION TECHNOLOGY
700208* -- Fusion Power Plant Technology-- Inertial Confinement Technology
ALKALINE EARTH METAL COMPOUNDS
ANNEALING
ANTIREFLECTION COATINGS
CALCIUM COMPOUNDS
CALCIUM FLUORIDES
CALCIUM HALIDES
CASTINGS
COATINGS
FLUORIDES
FLUORINE COMPOUNDS
HALIDES
HALOGEN COMPOUNDS
HEAT TREATMENTS
LASER FUSION REACTORS
OPTICAL SYSTEMS
SUBSTRATES
SURFACES
THERMONUCLEAR REACTORS