AB TOFI ORNL P 1943 EEEFEREE 1.25 14 116 MICROCOPY RESOLUTION TEST CHART NATIONAL BUREAU OF STANDARDS – 1963 B:"ORNL - ORNL -P-1943 Conf-660207-3 MASTER 111310 - ) } Y - 1840) . S RECENT SOURCS DEVELOPMMA HL, TIH AL:ROSPACE UTILITY* FEB 2 3 8988 F. N. Cilse Oak Ridge National Laboratory Oak Ridge, Iconnessee RELEASED FOR ANNOUNCEMENT IN NUCLEAR SCIENCE ABSTRACTS VI: ABSTVCT Ootaining the expected perfoi'mence of clectrical components and devices in a space radiation cnvironment requires a technique for simulating this environment. !nose devices primarily affectea ... · * * . by electrons are usually tested by: Van de Graaff accelerator irra- diations. However, radioisotope sources are also capable of sim- lating space radiations, and by biending two or more beta emitters it is possible to obtain energy spectrums which nearly match those As weed in the above, privately owmod rt data; or with the Commission, or din employment with such contractor. dianominates, or provides accen to, any tnformation purmuant to us employment or contract such employee or contractor of the Commalaslon, or employee of much contractor properne ployee or contractor of the Commission, or employs of toch oontractor, to the attent that person acting on behalf of the Commission" Inclades moyen- use of any information, apparatus, method, or procou diecloved in this report. B. Asames any liabilides with rospect to the use of, or for damage tonelttag from the of any information, apparatus, mothod, or proceso dlucioned in this report may not intrat racy, completeness, or wrofalnous of the information conta.lond in this report, or that we w A. Makes any warranty or represcatadion, expressed or ipaplied, with respect to the accu- Statos, por the Commission, nor any perton acting on behalf of the Commiuston: This report was prepared u an account of Government sponsored work. Noither the United LEGAL NOTICE . . . < ... 7 KK . . AT .. - 2 si OK. Wii observed at any specified altitude. Sources as large as 20 x 40 in. have been fabricated using 1/8-in.-diameter stainless steel tubes loaded with 90Sr. Eighty tubes, spaced on half-inch centers and each containing 12 curies of 90sr, produce a uniform radiation field of >1020 beta particles cm-2 sec-d at 2 in.. The energy spectrum of this source is shown in Fig. 1. A 347Pm source has been fabricated in whic the radioisotope is attached as a glaze to a ceramic backing. This source has a B NE 2 . Research sponsored by the U. S. Atomic Energy Commission .. under contract with the Union Carbide Corporation. :ONI - AEC - OFFICIAL OKHL - AEC - CINICIAL ... B I . r - . flux of >25-kev electrons of about 4.6 x 1010 electrons cm-2 sec- at 2 cm. The energy spectrum is shown in Fig. 2. Several advantages of radioisotope sources for electron irra- diation studies are 1) radioisotope sources are much cheaper in original cost and operating cost then conventional machine sources; 2) source output is constant and needs to be measured only once at known distances; 3) continuous irradiation time can be weeks or months, which is not practical'with machine sources; and 4) the sources can be used to simulate the electron distribution and . frequency in space, allowing more realistic "real time". testing. NA . ::-; 42 fa . 7 . * . NON ir VA YOL Y . . . . ::. . . . ....... ....... .. ORNL - AEC - OFFICIAL Obtaining the expected performance of electrical components and acvices in a space radiation environinent requires ii tecinique for simulation of this environment. Those devices primarily wifected by electron irradiation are usually tested by Van de Graaff accelerator bombardments; however, increased .no . .. attention has been given to use of radioisotopic sources in spece simulation chambers. The advantages of radionuclides for electron irradiation studies are: 1) the radioisotope source is much cleaper in original cost and operating expense than conventional machine :sources; 2) the output of the source is coostatic and need be measured only once at known distances; 3) the irra- diation time can be weeks or months, which is not practical with machine sources; and 4) the source can be useå to simulate the electron energy distribution and Ilux in space. Open-face beta sources have been investigated as a promising method for obtaining maximuua beta output. The possibility of release of activity from the surface by abrasion requires that such sources be used under specific experimental conditions; tiowever, under controlled conditions these sources are relatively safe and their use should not be denied to experimenters when maximum output is of major importance. Promethium-147, a pure beta enitter with a maximum energy of 223 kev and a half-life of 2.6 years, has been used for irradiation of dielectric materials to observe charge storage effects caused by trapping of incident electrons. For these studies electron energies between 20 and 200 kev are desirable at a Llux of at least 20€ electrons cm-2 sec-1 at a distance of . - 1 3. ORNI – AEC - OFFICIAL". ..:: . : e nawaran senin menawaran mengamanan m 2 cu from the source. Calculations indicate that a 70 curie 147Pm source will provide the desired characteristics: 1) if it could be deposited to a thickness of 25 mg cm-2 or less; 2) iſ it could be deposited within an area of 25 cram; and 3) if it could be used with a covering window of 5 ms cm-2 or less. Such a source has been designed and constructed. The 147 Pun source was made by first mixing promethium oxide powder homogeneously with potassium silirate powder in alcohol. This mixture was distributed evenly on the surface of the thin disc (1/8 inch thick by : 2 inch dia.) of magnesium silicate. After drying, the disc was fired at 1100°C for 16 hours to effect a reaction between the promethium oxide and the silicate fluxing agent. Subsequently & 1.5-1011 Pyrex glass protective overlay was fused ca the surface of the source by heating at 900°C. The glass covers only the center of the source, exposing about 1/4 in. of the rare earth glass source at the perimeter. Wipe tests oỉ the exposed source surface consistently yield dose rates of 20 to 30 mr per hr. This is be-' lieved to be due to the abrasion of the source and not to loose radioactivity.. No transfer of contamination fron the source to adjacent surfaces has been observed even when cycled over temperatures ranging from room temperature to 2100 °C and pressures from atmospheric to 10-5 torr. No variation in the amount of radioactivity observed in smear tests was observed after these cycles of temperature and pressure. It is believed that the source can be used safely in a controlled experimental program in which routine frequent smear testing is performed. Figure i shovs the completed source. The finished source had a flux. of electrons above 25 kev of about 4.6 x 2010 electrons cm-2 sec-' at 2 cm. . . . - - - - - - - mong T ao... . - - - . . .... . . " " *:- . .mi--- home w ithin en... .. mer ......... ... ... .. . .. mere . . Fig. 1 Open Face 2*7 An Source . i . omni-Aic - OFFICIAL Tigure 2 is an energy spectrum of the source, taken with an anthracene crystal. A counting rate of about 3.4 x 105 counts per minute was obtained by placing a 1/2-inch-thick lead collimator with a 20-mil hole in it on top : of the source. This source has a maximum energy of 175 kev and has a . . :: ... . maximum number of electrons at 75 kev. The source output measured with a thin-shell ionization chamber ivas 2000 r. per hour at 3 inches from the surface. Uniformity of distribution of the 147 Pra activity over the surface of the disc was determined by auto-radiography, using Polaroid film. Very large space simulation sources may be 'fabricated, using tubes containing posr or mixtures of radionuclides which may be proportioned to yield energy distributions needed for particular experimental irradiations.. Figure 3 shows a large or source deve loped for use in experimental irradiations of components of the pegasus micrometeoroid detection system This 20-in. by 40-in. source contains 82 individual tubes, each of which is loaded with ~10 curies of Sr absorbed on a molecular sieve. Each tube is 21 in. long, 7/8 inch 0.d. stainless steel with 20 mil wall thickness: Each end is Heliarc welded and leak-tested at less than 300 microns mercury . . : pressure. : . . . 2.... . . . - -. A total of 900 curies of Osr-90y provides an electron flux of 6 x 1.08 electrons cm-2 at 2 in. from the source face. Less than 2% of the total radiation was found to be bremsstrahlung as determined by absorption measurements. . Strontium-90 loading can be increased by use of undiluted ®Sr?103 to a maximum of 168 curies per foot of tube. This would increase source : output to ~1020 electrons cm-2 at 2 in. from the sources Tubes spaced on 1/2-in. centers produced a source with a highly uniform beta flux over the . " s asa " ... ORNL - AEC - OFFICIAL . . ..:.' : . ............... NV171330 - 33V - INDO 1 - INYO: :: .. :..: 04 4. .. .:. : ORNL-DWG 66-525 10,000 .. 8000 . . . . . . . . . 6000 - .................... . counts/min ......... .............. ..... .... .. ... ... ... ... 0. 250 . 50 100 150 200 : ENERGY (kev) Energy Spectrum of Pm147 Source. .. ܂ 1 .. .. ' ....... .. ..... .... . .. . .. ܀ ............... ... ܕ. . ܕr' '" . . ' . ܙ .ܪ. ܟܕ ;n rܢܐܢ ܙܗܕ..܆ ܪܙܫܙܚܝܺܙܚ.ܤ ܝܚܫܚܝܝܝܚܚܚܚܚܚܚܚܚ ܚܫ . -... ..܂… .. ܕ . . .. . .. . . . . . . . ، ، ،،، . . ܙ ܢܙ , . . ܇ ܂ ܃ ܂ ܃ ܃ ܇ ܀ : ' ܕ : ܙC ܙ . ܀ ، ، ، ܀ ܂. .. ܐ܀ ܙ . ܘܝ ܙ ܙ.ܫܚ . . . . ܂ . .. . . .. . . * . . . .. .....… . ܙ. ܟ . .. . .. ܙ. ܫܝܙ ܝ ܚ. ܀ . .ܫ.ܫ.ܫܙܝ .. ܝ. ܘ . ܫܚܝܙܚܚܙܫܫ. ܫܫܝܚ ܙ… ܕ ܙ ܝ . . ܫܙܫܙ ܝ ܗܙ.ܐ..ܫ .. ܐܢܝܫܫܝܝ ܫܫ ܙܫ܂ . ܙܢܙ ܕܙܫ . . ܕ ܫ. . . .ܫ ܙ . . . . . .. ܝ ...... . . . . . .. ... . ... ܚ ܚܗ̇ܝ ܝ. . . .. . ... . . ..... .ܚܚܚܚܚܚܚܚ .. . ܙ.ܗ . . . . . ܚ ܙܙܫ ܫܝܨܫܙ ܙܫܫܫܚܣܝܫܙܝܫ. .. ..ܕܩܫܝܫܝܝܗܪܢ . ܖ ܖ܇ ...ܝ. .: -. . .. .....ܝܐ ܫܝܝܺܐܙܫܺ .. -.ܫܫ.ܝܫܚܓܚ ܫܚܪ.܀ ܚ .. ,-; -... .. . .. ܕܿܪ ܪ ܝ... ܕܙܚܝܙܝܐ ܙܙ ، ܝ، ܙ ܝܫܫܝܫ ܫܫܫ ܫܙ ܚ . ܂ ܙ ܀ ' ܙ ܝ ܂ ܝܙܣܪ: ܚܕܚ ܙ ܙ ܂ ' .ܫ.ܫ-. . . . . ، ;. .. .. .. . . .ܙܙܫܘܝܫܙܫܙܙ .. ܕܨ ܝܙܕ ܀ ܙ ܝ ܢ ܚܿܫ. ܕܫܙܫܝܫ . . ܚܚܚ ܝ ܝ ،, . ܫ . ܝܙܫܫ. ܝܚܫܫ - ܕܝ :. ܕܚܕ. ܚܝܝܫ . . .. . .;.. .. .. . . .'ܙܟ݁ - ܀ . . -- ܕ .1 .. ܢ ܚܫ. ܫ ܫܫܫܚܫܚܫܚܫܚܬ.ܙܐ · ܕ ܙܙܗܚܿܝܝܚܝ. ܚܘܫܫܙ . ܫܫܫ ܫܚܝܬ ܂ ܢܚܿܚܙܫܕ ܝ. .ܫ.ܚܫܫܚܫܡܫܚܢܚܚܚܙܝ ܙܙ.܂ ܝܙ ܫܝ.. ܚܫܐ ܗܐ. ... ܗ ܕ ܪܝ ܗܝ ܙܗܘܝ.܂ ܀ • : : ܚܫܙܝ . . . ܕ ܫܫ. ...ܪܺܝܫܚ. .. . . . ، .. . ܫܝ ܝܝܫܫܚܗܚܗܗܚܚܘܚܚܚܚܚܚܚܚܚܚܫ ܙܙܛ..ܚܚܚܚܚܚܚ܀. ܨ ܙ ܩ ܚ ܝܫܪ.ܚܘܙܫܙܝ... .... -. -, -. .- . . - ܝ - - ܝ -.-- . ܢܿܫܫܝܪ..ܝܫܝܝܪܢܫܚܫܣܝܩܟܤܚܚܚܚܚܚܚܚܚܙܘ ܫܝ ܤܕܫܚܚܘܚܚܗܚ ܚܚܚܚܚܗܚܚܘܚܨܝܝ ܣ ܢܝܚܝܙܝܺܝܳܗ ܫܝܝܵܚ̈ܟ ܚܫܚܚܚܗܚܚܚܚ . . . ...Fig. 3 Large 20" x 40" gosr Beta Source .ܫܫܫܫܫܫܚܝܫ. . - ܙ ܙ ܫ ܕ ܙܒܙܡܚܕܐܫܩܬܟܘܣܘܙܕܕ:£. Stur ܕ ܫ ܫ ܚܢ ܚܚܚܵܝܲܪܚܵܙܫܫܚܪܙܝܚܟ ܝ. ܫܚܚܪܪܐܝܚܝܚܚܚܚܺܚܺܚܺܚܺܚܺܚܞܬܞ ܗ. ܪܫܩܫܐܗܙܫܢܢܐ. ܓܚܚܫ ܨܫܒܨܝܼܪܝܼܪܝܼܢ ;-; ܕ݁ܰܡܟܚܙܙܪܝܕܝܝܝܝܝܝܝܝܝܝܝܝܪܪܪܫܝܝܝܝܪ ܐ ܀ ܙܝܺܚ̈ܐܺܚ ܙܪܫܙܝܝ ܢܪܢܪܚܤܚܫܚܚܝܝ.ܫܚܝܺܙܚܚܫܝ. ܫܢܙܚ ܫܝܫܫ ܝܕܪܝܝܚܝܝܪܫܘܚܚܢܚܝܙܚܫܒܢܝܫܚܚ ܫ ܪܚܪܙ ܙ ܫܫܕܝܝܕܝܚܚܫܪܚܙܲܚܫܪܚܚܿܗܕܫܩܙܙ ܕܢܨ .ܚ ܝ̣ܒ̣ܝܼܒ ܝܼ ܫܩܚܝܪܝܒܫ ܫܝܫܫܙܝܫܪܐܚܐܫܝܩܫܚܬܐ ܡܬܚ : ܝܶܨܶ .! ?: ܝܕܚܝܚܝܟܚܚܝܫܫܝܝܟܫ , . .. - - .ܚ . ܙ ܘܢ ܕܡܢ ܕܪܩ ܟ . ܘ ܗ ܙ ܗ. ܫ ܝ ܙ ܂ ܐܫܐܫܝܵܚ̈ܫܰܚܪܚܝܝܚܚܚܿܚܚܚܚܚܚܚܚܚܚܵܚܫܫܝܚܫ ܫܙܚܚ. ܚܚܪܪܙܪܬܚܐ ܢܚܬ. ܩܕܪܐ ܫܲܒ ܢܵܕܵܢܸܫܐ̱ܟ݂ܘܿܒܼܚܲܕ ܚܲܚܵܝܼܕܝܵܪܪ ; ܟܫܣܝܫܘܝܪܚ̈ܚܵܚܲܢܲܝܼܫܝܫܒܝܚܸܗܵܚܲܪܩܫܫܙ.ܫܫܚܫܫ.ܬ̣ ܐ̱ܝܬܫܪܫܢܗ݈ܝ ܐܚܢܚܝܫܚܚܚܚܚܚܚܚ ܫܚܝܤܫܝ ܚܙܬܐܙܝܫܚܢܩܙܐܤܣܫܤܗܨ ܚܝܪܝ ܚ ܪܕܝ. ܀...ܚܪ ;.;iܪܚܼ ..ܕܫ ܚܕ : ܂ ܚܲܝܵ ܫܵ ܚܲܚܲܪܟܝܦ ܀ ܀܀. ܀-1 .*،ܐܼܿ. . ܘܪ: ܐܬܪܤܝܚ ܤ ܬܝܪ ܀܀ ܚܲܚܫܪܚܫܪ .. ܪ ܗܪܙ: ܙ ...ܕܫܕܫ ܬܪ ••• ܫܚܪܫܚܚܚܝܚܝܚܚܚܝܺܚ̈ܫܺܫܝܺܐܫܺܕ݂ܺܚ̈ ܙܶܚܚܺܚܺܗܐ.ܝܝܺܝܝ.ܝ.. ܫ . . ܫ ܝ. ܫ ' ܫܫܫ ܚ.. ܝ ܫܝܪܚܝܺܝܚܳܚܝܙܫܚܪܚܪܚܪܚܪܪܚܚܝܪܝܕܕܫܫܬ݁܀ . .. . ....... ܚ܀ . ܢܨܙܚܝܚܫܫܚܫܚܚܝܝܚܝܝܝܚܚܝܕܙܫܫܫ ܙ ܓܪܐܝܟܿܪ. ܚ...ܘܚܐܝܺܫܝܺܚܫܢܰܝ̈ܗܝܣ-... .... ܪܝܪܝܝܝܫܫܫܫܚܚܲܡܲܪܚܲܚܚܪܘܺܚܫ -… ... ܘܺܗ݈ܚܬ. ܚܕ. ܗܚܲܝܘܿܚܲܚܲܝܚܝܪܨܚܚ..ܝܩܫܙܗ݈ ܀ . { $ { } { • • • • • es x .-.-.-.-.-.-..-.-.- ta -- ܂ . . ܚܿܚܪ. ܪܙܝܫ .ܕ.ܪܝܫ ܫܕܫܚܫv .܀ܚܙܝܙ - ܙ ܙ . ܝܐܝ ܙܘܙ. ܙ ܙܝ .ܙܝܣ .--.: ܙܙ -In ܇ ܚ ܝܘܗܚܝܕܚܚܚ . . ܙ . ܚ ܘܙܙܝܚܫܘܚܫ.. ܊ ܂ . . . .. . . .. .. .ܫܙܝܗܘܫܚܚܫܚܫ ܚ.uo ܙܚܬ܆܇܇ܙܙ ܙܙܙܙ ܐܕ ܘܘܚܝܚܟܢܝܩܢܟܐܚܝ. ܝܫܫܘܗܝܚܚܚܗܚܚ ܗ....-,{ ܚܚܚܚܚܚܚܚܚܚܚܚܚܚܚܚܫ.܂ [ . . 1 ܨܗܕ * . . . ܂. .. .. .. .. .... . .. . . . ..... ...... ܫܝ.. ܚܝܫ. . . .- .; : ܪܗ ܫܫܘܫܚܟ-- .- -ܗܿܙܘܗܘ.. . ܙܢ. : ܚܚܚܚܚܚ ܗܚܚܫ ....…..… .. ܂ ܂ ܙ ܙ ?"'nr arܚܫ ܝ ܚܫ. ܝܘܙܚ:.-.. .ܫ .-..... . ܬ ،،، ، ܕܙ. ܗܳܕ݂ܶܐ ܚܫܝܬܝܝܝܚܫܪܚܕܝܫܐ. .. .. ܚ.-... ܘܫܙܙ ܙ13 ܚܙܐ ܙܗܠܐ ܝ ܚ .. ܕ . ܙ. -ܗ̇ ܗܿ...ܫܪܚܫܪܪܪܪܪܚܪܘܗܝܫܣ. ܃ ܃ ܝܼ ܝܼܚ ܚܚܚܚܝܚܝܝܢܚܫ.... ! . - . - 9ܙܐ 30 ܙ7ܐ . . . rifii rf f1 if ' 11 ' . ܚ ܢܝܚ ܥܡܗ. ܚ ܗܚܫܚ....... . . . .. .. . Our . ; MO . . . .. . . . ܙܟ . ܀ . ܝ .ܙ , . ܂ . . . ܀ ܀ . . .. .. . ' . . - . ........... .... " ...on. . .:: ORNICAEC - OFFICIAL area of the source, extending to within 1 incir of the edge of the source. The energy spectrum from a posr source is shown in Fig. 4. This spectrum was obtained using ea anthracene crystal to measure the radiation from tubes oi identical geometry but with microcurie so Sr loadings. This source was prepared for NASA to be used by Lockheed at Dawsonville, Georgia, in a .... om ... ....... vacuum chamber for irradiation of pegasus panels. The only limit to size of such a source would be the size of the hot cell in which such a source is . assembled. .. . . . .. ; Krypton-85 sources appear to have a good potential in aerospace devices. When considered from a safety standpoint 85Kr has several desirable char- acteristics. In case of capsule failure the gas is rapidly dissipated ana if ingested it is rapidly expelled from the body. The possibility of equip- : ment contamination by a leaking source is almost non-existent. A: 85Kr source was developed for use with a helicopter close-order formation keeping system under development by Industrial Nucleonics. This source was designed for production of 98-kev x-rays from the SSKr 0.67 Mev: beta on 4-mil uranium foil placed on the inner surface of a 20-mil stain- less steel source capsule. Output from this source is shown in Fig. 5. A possible objection to use of 85Kr is the lack of a sharp energy peak when.. : measured from a distance. . of interest for radiographic inspection techniques of aircraft com- ponents is the development of very high specific activity 182 Ir sources. These sources, prepared by neutron irradiation of <2-mil-thick iridium ribbon followed by melting to form small metallic spheres, can be provided · with specific activities >600 curies per gram. Current work with high Page : : .. .. . - ::.ORNL - AEC - OFFICIAL ORNL- DWG 66-524 .. counts/min 500 2000 1000 4500 ENERGY (kev). Energy Spectrum of Sr Source. ORNI - AEC - OFFICIAL ... O'RNL-AEC - OFFICIAL . ::.. : .. . . . . . . . . . . . . . ORNL-DWG 66-523 000ʻoi : 93 kev 5000 0.54 Mev sr 100 ft counts/min 200 ft - 300 ft BACKGROUND . .. 01 0: 30 60 150 180 210 $90 120 CHANNEL NUMBER : :.. Fig. 5 .. . ORNL-AEC - OFFICIAL .. : : . ...... ORNL-AEC - OFFICIAL :: . . ,:. .. .. . ..:. .ORNI - AEC-OFFICIAL .. -- - .... . - - ... ....... .::... . . ... . neutron flux irradiation indica te >1000 c/& Iridium can be prepared by this method. This is 4-5 times as high as sources now available to radiographers and should provide better image definition in radiographs than now obtainable. Tigure 6 shows a typical spherical pellet of 700 curies of iridium per. sram. Approximately 200 curies or 1921r is contained in a pellet of this size. Very thin sections of lightweight materials such as aluminum and titanium can be radiographed using 147Pın sources of the type shown in Fig. 7. The upper limits of radiation output from these sources are controlled by .. absorption of the low energy radiation within the source material. For example, the output from a source containing 250 curies 247 pm in the form of a pressed pellet of promethium oxide, 7 mm dia., can be increased only about . 10% by increasing the loading to 500 curies and holding the diameter constant; however, by use of intensifing screens and high speed emulsions, exposure time can be reduced to practical limits. Figure 8 shows typical radio- graphs using 147PM. Many sources are designed to meet the needs of particular experiments. A study concerning the effect of zero gravity on radiation-induced chro- mosomal aberrations in white blood cells was conducted using 32P sources. An irradiator was prepared in which 32p sources were inserted between plastic chambers containing blood. Figure 9 shows. 20 of the sources during one phase of fabrication: Filter paper attached to platinum backing places was saturated with solution containing B2P, then dried, and finally satu- rated with a solution of catalyzed epoxy resin to hold the 32p in place. Sources prepared in this way were found to meet the requirements of one:..-::. -; . ::. .:: : . .::. . ... . .. . . . . .. ......... CRNL - AEC-OFFICIAL .;.. .. . . .:. - ....................... ... * vers..... Fig. 6. 192I: Sigh Specific Activity Point Source : - : :.- . :. .. ::. ; ORNI - AEC - OFFICIAL :ORNI - ASC-naririni : " .. .. '. MAAR Wory.... Nii bakalanditawarantowane na cor in interessant in the interior writing investiciniisi m k without women ingent Coming Klu<*rare ORNI - AIC - OFFICIAL Fig. 7 Source Capsule for 167 Pa Radiographic Source . ..... ........ . .. ............. ...... . m · · •- -. .. - comme ... ... . . . ... -- - r. Fig. 8 Radiographs using 247 Pa Souce *? ; ORNI - AEC - OINICIAL.. . . . . . . Horosevanemo. . . . :". .. ORNI - ATC orricial : . \" . . . . مه. . . . . . . . . . . .. م ن. .. .. .. ... .. . 1 "* ومتش. . . . . . -- .. *• •• - . . .- . .." " . . همه...من دخمامته ۱۸اد " . .. . . . دنتی س محملسكس ته ننه ... ...م ممم ... ن . - . . ... ة . م . .. م بز مت .. .. .. .. .. سهم . . . . .... تيم .. منسمحض سسس .. سامسسسسسسنن .. ه. .... .......... سمه ده د " " .. :': .. ماه عدهن منه هيمسه حمله .. .. سه ته ام .. همه مساعده عوامماس ته نه تمام Mo . R ecom Blová Irradiator Asserably .... Used on Gemini III Flight Fig. 10 .. .: .::. than . I ' i . Wahaimaa kubishite balance....mmm ..mmm come i novom... 2 : INCHES . 1 - *OrNi-AEC - OFFIC ORNL - AEÇ - Officiais: . . . MOUNTING BRACKET : SHEAR PIN PROTECTED TAPE DECK URANIUM SHIELDING ( 4 SPHERE) - GUARD. LANCHOR TO PLANE STRUCTURE COGO SOURCE DIRECTION OF FLIGHT . . . . . Fig. il Flight Recorder Beacon - - . .. .. . . ORNL - AEC - OFFICIAL :: . . ::ORNI - AEC - OFFICIAL , -, ... ..::: ". umartesi is ---. . .:. :. . RNL - AEC - OFFICIAL . : .. n . ... . ... www homogeneity of 328 over the entire source area and of reproducibility of : output characteristics, and were used in the Gemini III space flight. The entire assembly is shown in Fig. 10. Locating flight records from aircraft involved in crashes can be made easier by use of radioactive beacons. A device utilizing boco has been developed and meets all FA1 Slifications concerning operating range, radiation exposure, operating 1:fe, power supplies, and environmental conditions under both normal ani crash situations. Less than 10 me of the isotope is required in a high integrity stainless steel capsulė. Figure 12 shows design details of the source and breakaway, shield; alternative designs have also been considered. In general, radioisotope sources should be evaluated in terms of the · particular use proposed for the source. While most sources can be fabricated to meet given safety requirements in nearly all eavironmental extremes, i alpha and beta, emitters require special considerations due to the loss oi .. radiation output in capsule materials and absorption within the source material itself. By careful evaluation of the intended use of the source, one can maximize output consistent with capsule integrity requirements. . :. ] . . ... · .. . . . .- . . . ; .'.. . . . . . . . . . . .. o . . .. . . END . -- DATE FILMED 3/ 25 / 66 th .. . . 'I