Kodak reports on: 2 more infrared transmitters that have to be considered . . . picturing slow neutrons . . . h o w to look around in the tunnel
Uniquely polycrystalline facts Since materials from which to make infrared-transmitting optical parts are selected by a mental process different from the one used in selecting a brand of shoe polish, a thin veil is hereby dropped: KODAK IRTRAN 1 material is our unique polycrystalline mag
nesium fluoride. This transmits usefully from 2μ to 8μ, over which range the refractive index runs from 1.37 to 1.26. It there fore wastes little on reflection. It has good microwave charac teristics and is comparable in general ruggedness with fused quartz, which is a great deal better than most optical glasses.
sheet without the film and then quickly pull it out of the neu tron flux and put it in contact with the film. As to whichfilm,we suggest you first read]. App. Phys., 33, 48 and Nucleonics, July 1962, pp. 60 and 61, and then ask for afilmrecom mendation from Eastman Kodak Company, X-ray Division, Roches ter 4, Ν. Y. Nice big sheets of gadolinium are not stocked by most neighborhood hardware merchants nor by us. Maybe your best bet after all is the 1°S scintillator. A prominent role in all this has been played by a gentleman named Kuan-Han Sun, who once worked for us before his interest turned from non-silicate optical glasses to nucleonics. Married one of our x-ray researchers and took her off with him. Lovely gal whose name was Laura McGillivray.
KODAK IRTRAN 2 material is our unique polycrystalline zinc
Cosmic film from France The cobblestones seen in this electron micrograph are grains of silver halide stick ing up out of a gelatin ma We now announce KODAK IRTRAN 3 trix. Originally prepared for optical material, unique polycrystal use outside the air blanket line calcium fluoride. It is clear enough to record the ambience of in the visible so that you can see through the universe. it to line up your system. Transmits to We must remember that 11 μ. Having no cleavage planes, it all matter is opaque below trounces monocrystalline CaF2 for about 2000À and that the shock survival, mechanical or thermal. tunnel is long and dark all True, the IRTRAN 1 material is even the way to x-rayland; for everything animal, vegetable, minbetter against shock and water, but eral, or gaseous is prone to electron transitions. IRTRAN 3 takes the lead on withstand The light in your eyes, of course, goes out at around 3800Â, ing a steady 900°C for 1 hour in air but any silver halide photographic material will get you down without forming any significant oxidation film. Index at 0.656μ, to 2500Â. The next 500À is sticky: you spread a fluorescent 1.4324; at 8.25μ, 1.3444. Maximum size at present: 5" diam oil over the emulsion to convert the energy to a wavelength eter χ VA" thick. long enough to penetrate the gelatin. Below 2000Â this stratThe newest of all, KODAK IRTRAN 4 agem poops out because even the oil robs you. At this point material, is our unique polycrystalline many years ago a spectroscopist named Victor Schumann had zinc selenide, a substance that trans the bright idea of eroding gelatin away with H2SO4 to uncover mits usefully from 1 μ to 21 μ. Still lim the halide crystals. This worked fine. Schumann plates also ited to a maximum diameter of 2" and proved useful for registering the focused ions in Aston's early thickness of VA" , which may suffice for mass spectrographs. your eval uation and planning purposes, About 15 years ago we improved on Schumann plates by a should you have any. With a refractive technique that left only enough gelatin to keep the grains index that descends from 2.5—much apart, as seen above. We call the product KODAK SWR Plates lower than that of germanium—opti and still recommend it unless you need high sensitivity so cal homogeneity is less exasperatingly desperately that neither granularity nor price can stand in difficult to attain. your way. In that event we can arrange to import for you All these KODAK IRTRAN materials have very low emissivity be some 180mm χ 35mm strips of film from Kodak-Pathé. Our cause we have worked like dogs to get the absorption out. Discuss clever French cousins have developed a very tricky centrifugal all this with Eastman Kodak Company, Special Products Division, coating technique that permits them to paste down much Rochester 4, Ν. Υ. larger halide crystals than the SWR kind, resulting in le film TYPE SC5 (environ 10 fois la sensibilité du film S. W.R. vers The Sun play 1200Â). Neutrons aren't much good by themselves for exposing photo If $72 for 24 such strips is not out of scale with the magnitude of graphic materials. Yet a mere few thousand thermal neutrons/ your thinking, get in touch on this matter with Eastman Kodak Com2 pany, Special Sensitized Products Division, Rochester 4, Ν. Υ. If mm can give decent photographic images. We don't mean you need nothing more special than a new free booklet entitled tracks, either. We mean continuous density, such as you might "Kodak Materials for Emission Spectrograph};" same address still find useful for neutron radiography (read the wine level inside applies. a lead amphora), neutron diffraction patterns, neutron flux Price subject to change without notice. measurements, etc. The topic of photographic detection of neutrons is too quiet for our liking. Let's have a little noise. Eastman Kodak Company ads like this have been appearing for 10 years. They suggest that w e make a wide variety of products. You do it by a triple play: thermal neutrons activate 10B Possibly you have at one time or another thought of buying one to emit alphas, which scintillate ZnS(Ag), which gives off but, not knowing h o w to go about it, have said, "The devil with visible light that exposes the film. For sharper images at the it." A r e you interested enough to send for a pocket reference book expense of longer exposure time, you can use a neutron activa that m a y help y o u and us achieve mutually beneficial contact? If so, address Eastman Kodak Company, Dept. 8, Rochester 4 , tion technique involving an appreciable half-life. There are Ν. Υ. It is a tiny bit out of date, but that can't be helped. (Everybody gadolinium, which works by an η,γ reaction, and dysprosium, dies a little each day.) which works by β decay. Expose such a neutron converter
sulfide; useful range, 1μ to 14μ; refractive index, 2.29 to 2.14. High index advantageous for lenses. Enjoying wide favor here and abroad among spectroscopists for its chemical and ther mal ruggedness.
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ANALYTICAL CHEMISTRY
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