UNITIZED SYSTEM OF IMAGE INTENSITIES USING FIBER OPTICS. Progress Report, October 1, 1960 to June 22, 1961

Technical Report · Thu Jun 22 04:00:00 EDT 1961

OSTI ID:4741245

Kalafut, J S

Four light intensifier types were processed. One had a 5-in. diameter fiber-optic input window and a 1-in. diameter fiber-optic output window. The other three had 5-in. diameter fiber-optic input windows and borosilicate output windows. Two of the latter displayed stable photocathodes with luminous sensitivities>40 mu a/lumen. Of these two both had a vast amount of cathode pattern; one also had high background characteristics. The fiber-optic faceplates displayed circular semi-opaque patterns in the body of the glass, but the luminous sensitivity of the pattern area varied only slightly relative to the clear areas. The single first-type intensifier exhibited a high (about 100 mu a/ lumen) initial luminous sensitivity that decreased at the rate of about 1 mu a/ luinen/hour because of a leak in fiber-optic window. The tube sensitivity to leaks proved to be far greater than that of present leak detectors. Experiments were performed on tubes of similar design to reduce and control the high background observed in these intensifiers. Partial success was achieved with selective heating, high voltage seasoning, and VACION pumping. Sudden application of full operating voltage to one tube was found to increase its susceptibility to field emission glow. Tests were also performed to develop substrates to prevent interaction of the lead glass with the alkali metals employed in photocathode processing. Tests examined effects of various things (MgF layers, etc.) on S-11 cathode processing at ambient and elevated temperature. MgF substrate showed a resistance to alkali penetration at elevated temperatures. Similar S-20 processing experiments were performed. Lime glass substrated faceplates arrived and proved acceptable. Leaks in the fiber-optic regions were sealed with silicone resin. Work on the ASTRACON with a photocathode made on a plain borosilicate input window centered on developing suitable photocathode processing techniques and designing the necessary electron optics. Fifteen photodiodes, eight with photocathodes, were processed and tested. Average luminous sensitivities were mediocre, partially due to nonuniform antimony evaporation. Multi-alkali (S-20) processing was dropped in favor of cesium antimony (S-9) processing. Eleven photodevices made after the change showed better uniformity and the last one displayed good response. Development of an Astracon using fiber-optic windows on input and output ends with photocathodes made directly on the input window involved designing, building, and test-leaking fiber-optic input and output sections. The decision to make the orthicon entirely of soft glass to permit use of frit sealing techniques on the fiber- optic faceplate was made. Breakage difficuities in fabrication of the image stem were encountered. (D.C.W.)

• Research Organization: Westinghouse Electric Corp. Electronic Tube Div., Elmira, N.Y.
• NSA Number: NSA-17-018543
• OSTI ID: 4741245
• Report Number(s): TID-14035
• Country of Publication: United States
• Language: English

Related Subjects

ALKALI METALS
ANTIMONY
BORON SILICATES
CALCIUM OXIDES
CATHODES
CESIUM
CURRENTS
DIODES
EFFICIENCY
ELECTRIC POTENTIAL
ELECTRON TUBES
EVAPORATION
FABRICATION
GLASS
IMAGES
INSTRUMENTS AND INSTRUMENTATION
LEAD COMPOUNDS
LEAKS
LIGHT
LUMINESCENCE
MAGNESIUM FLUORIDES
PHOTOELECTRIC CELLS
RESINS
SEALS
SEMICONDUCTORS
SENSITIVITY
SILICONES
TEMPERATURE
TESTING