Doc 0000173607

,; - ~~ ·. ~~~ '. ~ ; ·· {;~,~;,~~~~. .. :~--.. .: ~----~-----~ :::..;. ._ ;,. t:r~~~~~;~ 1 ~ :·:-~-~- . . { . , :-{ / .·:--...:,:J.;_ ~ J INTERIM REPORT PART II LIGHT SOURCE EVALUATION / I ·. February 1970 - o,J' .-> ·~ ·~:.-.:·,· ,- .""'\ ~:·\t1 ~-;~~--~ 1. FACTORS AFFECTING THE PERFORMAI'JCE OF PYROTECHNIC .·.-;'-""·."':·.tiS MIXTURES The object of this study is to investigate the feasibility of utilizing high intense light emitted from rapidly burning pyrotecnnic mixtures for optical int::apacitation. Several mixtures have been selected for initial study. The compo.sitions of these mixtures were itemized in a previous progress report.l It is useful to review the mechanisms of pyrotechnic burning and the important factors, relevant to light emission, so as to fully under st~_nd the utility of this approach. 1.1 DESCRIPTION OF BURNING PROCESS The basic ingredients of most pyrotechnic compositions consist of a fuel and an oxidizer. These ingredients s£1ould be stable under normal shelf conditions, yet they should be easy to ignite. Further, once ignition occurs, the heat released during burning should be to. .sustain the burning. process. sufficien~- It is useful to consider the following model to explain the burning ..... --= .-· behaviorof"il:rpyrateeim~ixtaxe.·-·'"" ~-~---~- ~ ·UC I Three thermal zones are established when an illuminating composi tion is ignited and burns propagatively (see Figure 1). I· ll . Air Flow //1 . Qs.. ) ~*-! e Tf ---- ~--"~""';....._·__.:,..:1 II< Qc). c e Q) E-1 Ta - - - - . :U ) ~ii"'--< = Flame Temperature ~~ = Ambient Temperature = Distance Below = ·~·-··· ~~;: :j~ Burning Surface -;.,·---~ Figure 1. Profile of Combustion Zone 1 ;:., - %~'Fl'Ei2;;,~; L .·.·. .... ~~:'.~~:~-~~:-~:.~~~-~{,..;.·L-~·'.:-~~~i;~:.~:~:;.:..::.i:...:..··~~---;,.:~ -~ . . .:-~-/~ . ... ~~~- ...... _.. ~:-.:~-~"---.~-.--: .) .. :: .-:·-: .;I ~ ::·;-~ ~~:~ ~;! Zone A is essentially the "burning surface". Both exothermic and endothermic reactions take place resulting in the formation of gaseous fuel and oxidizer intermediates. These intermediates react exothermically in the flame zone. Usually the pyrotechnic is designed to be fuel rich and the excess fucl.reacts with oxygen from the atmosphere. In these cases the flame si~e and intensity arc somewhat dependent upon the required environmental oxygen and its availability. The energy required to form the reactive intermediates are generated by the exothermic reactions which occur in the flame zone and in Zone A. The dominant heat transport This page features stylized text overlaid on a dark background with a blue-tinted graphic of a vault door on the left. The prominent title "THE BLACK VAULT" is displayed in a distressed, white, handwritten font. Beneath this, white text provides information about the document's origin, mentioning it's from "The Black Vault," an online database of declassified government documents, specifically the "MKULTRA/Mind Control Collection" which contains over 20,000 pages declassified by the CIA. The text also indicates the entire collection is free to download at a given URL. No photographs, handwritten annotations, stamps, forms, diagrams, tables, redactions, or visual evidence of experimental procedures are visible on this page. from the atmosphere. In these cases the flame si~e and intensity arc somewhat dependent upon the required environmental oxygen and its availability. The energy required to form the reactive intermediates are generated by the exothermic reactions which occur in the flame zone and in Zone A. The dominant heat transport mechanisms are radiation feed back from the flame and conductive transport from condensed phase reactions which occur in Zone A. Energy from Zone A is also transferred to Zone B which may be considered the pre-ignition zone. Directly below Zone B is the remainder of the unreacted pyrotechnic composition, !!! . or Zone C. The radiative heat transport from the flame to Zone A can be described mathematically by the Stefan-Boltzmann equation i - I = e oF (T T~ ) (1) where I is in terms of energy per unit area per unit time (e.g. cals/ 1 cm2-sech'~·"i's'the· ertriss~tm:t-,-·~ St'efah ...~ ltzmamr--"' ..... '" constant, F is a flame shape factor Tf is the flame temperature and T 1 0 is the temperature of the surface receiving the radiation. The temperature in Zone A is further affected by the local endo thermic and exothermic transitions which occur in forming the reactive intermediates. The important reactions which limit the burning rate of the pyrotechnic are the endothermic processes. Typically, these processes involve a. phase changes, and ~f"L •. ·~ b. pyrolytic decomposition to generate gaseous combustion reactants. Under steady-state conditions the thin pre-ignition zone (i.e., Zone B) can be assumed to. have a uniform temperature. For simple J:;: ~ ........ ,.· 7j systems this zone has thicknesses in the molecular size range and its 1 temperature is governed .almost completely by the endothermic processes ~H taken place. ~~-~. ~,: 4"'~;~'-';;:;,_:~,{~----~. -·. . . .· · .~ - ;· :~. ;;.. L-_),~;.;<_,_,;.::; :~}_ L':~ ~ :/j'};.:.'~;j~S;::;:-~;;'~~-Y~;;dt;:;::b"~D::~:Ci~.::;.;::.~~~:; :: .. :. . :..:.:::..~ ~ ~;,._ __ ·"··-·"'·'-... _. ... ~t~~,2~~~~~~' ~"-' = ~. ...: :,:j {~ The tempcruturc j:)rofile v;ithin the body of the pyrotechnic (i.e. 1 - II Zone C) can be approximutc~ by the Roscnthul cquation2 = Tx Ta + (Ts -T ) exp (-vx/a.) (2) 0 I ··,i:-.• where Tx is the temperuture at distance x below the reacting surface (Zone B) Ta is the ambient temperature Ts is the temperature within 1 1 Zone B v is the burning rate, and a. is the thermal diffusivity of the 1 The document is a title page for an interim report, dating from February 1970, with the title "LIGHT SOURCE EVALUATION." There are several handwritten annotations, including a number "2-4" and a signature that appears to read "Returntg" at the top of the page. A circled number "186" is present in the bottom right corner, likely indicating page numbering. There is visual evidence of redacting or obscuring content; however, no specific details about the nature or subject of the redactions are discernable. The page contains a scientific illustration of the "Profile of Combustion Zone" for pyrotechnic mixtures. This diagram depicts thermal zones, labeled A, B, and C, within the burning process, indicating temperature fluctuations over distance from the burning surface. The illustration also shows airflow and defines parameters like flame temperature and ambient temperature. The document includes numbered headings, body text, and a figure caption. There are no photographs, handwritten annotations, stamps, or redacted content visible on this page. -T ) exp (-vx/a.) (2) 0 I ··,i:-.• where Tx is the temperuture at distance x below the reacting surface (Zone B) Ta is the ambient temperature Ts is the temperature within 1 1 Zone B v is the burning rate, and a. is the thermal diffusivity of the 1 mixture: It should be noted that thermal diffusivity is related to more conventional th.ermaLpr.operties.,"i. e. •. . . ----.. ,~ = a. k/ pc, (3) where k is the thermal conductivity, p is .density and c is the specific heat. 1.2 FACTORS AFFECT!NG LIGHT OUTPUT The distribution of radiation in any spectral region is determined by the chemical nature and physical state of the products which emit in that region, and the temperature reached by these emitting species. Th.e rate at which a pyrotechnic mixture bums depends on the amount and rate at which heat is evolved. Sufficient heat must be produced to raise thetempe;ratm:a~:othe::..:inoredien:t..s.:ic;.a;..;p.oint.at.;.wbtch--an~xother:mic.--~.::--.. .;;.:~~--;. reaction will be initiated and the reaction rate must be sufficient to 1 more than compensate for heat losses in order for the burning to be l~:'o} sustained. Mathematically, the burning rate, v, can be related to the energy fedback from the exothermic processes and the rate determining endothermic process which must occur to produce the reactive inter- ~xi mediates ~f~ j = v E (I)/p (AH +CAT) (4) ~1 tn where E (I) is the radiative, convective and conductive heat flux fedback to the pre-ignition zone, AH is the heat absoroed in the pre-ignition zone by the endothermic processes and C tJ. T is the heat required to elevate the temperature of the pyrotechnic (i.e., at the boundary between ~1t~· -~ ~: Zones B and C) to the reaction temperature. The latter (p C AT), can be -~(:'J~I best described as a heat loss term. The rate of burning, the products formed, and the flame tempera JtU ture are affected markedly by the composition-of the mixture, as well as by the physical condition of the materials and the ambient conditions :;--;;.-~ ;.t under which it is burned. Some of the more important factors which affect [t:J i the performance of light producing pyrotechnics which were considered in ir·,,, our initial selection compositions are as follows, ~r~--t~ Jl~~z;:~'k~~f~':S:'•.y·;,:~;,;:;-t;i;Sft1t~~!'~~7~'f-:'i~~rt~~~~'•':2':~'2:-'1,'(":''1';:,cr:;:;;;r;~{;"'7 J:-~i'g-.:--: - ~ ••· .· ·-·~.-.-.'.·- . .. . .. -. . i...;. . :.... . --:. . ..\i. . ·.lo O · ' _ _,. which affect [t:J i the performance of light producing pyrotechnics which were considered in ir·,,, our initial selection compositions are as follows, ~r~--t~ Jl~~z;:~'k~~f~':S:'•.y·;,:~;,;:;-t;i;Sft1t~~!'~~7~'f-:'i~~rt~~~~'•':2':~'2:-'1,'(":''1';:,cr:;:;;;r;~{;"'7 J:-~i'g-.:--: - ~ ••· .· ·-·~.-.-.'.·- . .. . .. -. . i...;. . :.... . --:. . ..\i. . ·.lo O · ' _ _,. .,.,.,l>-o, . , :·_ · . < . . ..... . ..::. -·~ ;.:.·.·-":...~ •. -.. _. 1. heat of reaction 2. composition of emitters 3. particle size 4. consolid.ation 5. pyrotechnic diameter 6. container de sign 1.2 .1 Heat of Reaction The heat of a reaction is defined thermochemically as the difference between the thermodynamic heats of formation of the reactants and products of the reaction. For example referring to the energy dia 1 gram shown in Figure 2 one selects a pyrotechnic mixture having 1 substituents which have a higher heat of formation than the reaction products and one which requires a minimal amount of input energy, -- 6. Ha, to initiate burning. = R Pyrotechnic Components (Reactants) . = P Combustion Products , ' , • ' ,. -R - , , ' ' t ' ' .. ' - - .. p .. -'-.- Reaction Path ---,~ Reaction Energy Diagram - ', ~r':V:11'l!dii.L,.:: _ ·-:-•i·-"',.,1"_ .. ;:,~ ··.·-~--~~ ~.;-~ 1.2 .2 Desired Output Spuctra ~::; {~~ ·-J~ The ultimute pyrotechnic composition must emit intense light in regions most sensitive to the eye. It can be seen from the "standard observer curve", shown in Figure 3 that the eye is only sensitive to a very narrow region of electromagnetic radiation. '·' .. ·' ; .. ... ,.. Wavelength, millimicron Figure 3 •... Standard Observer. -Curve.. ·--·· I This region extends between approximately 400 to 700 m!Jo (or 4000 to :s:_,,., II 7000 Angstroms). In Figure 4, the visual response curve of the human eye is shown. In this figure the effective radiation, 1n terms of photometric units (lumens) as a function of wavelength is shown. The absolute 1A~it photopic luminosity is defined as the ratio of the electromagnetic flux sensed by the eye (in units of lumens) to the total radiant flux (in terms II of watts). The most sensitive region in this narrow spectrum lies between 500 and 5 60 mf.L. Therefore, for effects related to visibility of the light source, the pyrotechnic mixtures should be designed to emit strongly in this wavelength region. A separate The image is a scan of a typed document page with a textured, speckled background, possibly indicating it was received as a photocopy. The page contains only text and a single mathematical equation. There are no photographs, handwritten annotations, stamps, forms, diagrams, tables, redactions, or visual evidence of experimental procedures. The text itself describes different zones within a burning process, specifically referring to "Zone A," "Zone B," and "Zone C" and discussing exothermic and endothermic reactions, heat transport, and chemical decomposition. The mathematical equation, labeled (1), appears to be the Stefan-Boltzmann equation related to radiative heat transport. The document page displays dense, technical text, including mathematical equations and scientific terminology related to pyrotechnics and thermal properties. There are no photographs, handwritten annotations, signatures, stamps, forms, diagrams, schematics, or organizational charts. The content is purely textual and includes formulas for temperature profiles, thermal diffusivity, and burning rates, along with a discussion of factors affecting light output in pyrotechnics. The page also exhibits a page number "3" at the bottom center and contains numerous small, dark speckles scattered across its surface, particularly in the upper left corner, which are characteristic of the document's age and condition. to the total radiant flux (in terms II of watts). The most sensitive region in this narrow spectrum lies between 500 and 5 60 mf.L. Therefore, for effects related to visibility of the light source, the pyrotechnic mixtures should be designed to emit strongly in this wavelength region. A separate ·question arises as to ~.;.:·····t whether optical incapacitation effects are similarly correlated over the ~t:~ visible range. This answer is not known at present.but will be assumed . ~~''t ~- to be positive for the present. Special design features must be ·included in a pyrotechnic to insure that a significant fraction of the total radiation emitted by the flame is in the visible region. The emission from a pyrotechnic flame is composed of line spectra, band spectra and continuum. The latter is directly dependent on the temperature of the flame. The continuum is essentially blackbody or grey body radiation. The distribution of the radiant energy versus wavelength can be estimated from Planck's equation ~::ft:,:~J ,~~'gj;;~'f.~ff!!fi7Cii¥i2~~;m0t'~I'~z~y:·¥;E~~;;~;.~,.;;;;~0iiS<;'}F~$J~S\~~~1'$ .·,·· - .<c·.:·:.;-:·~~-:~:ii:~::~.~:~.;~~-~·~·.1~:22-:,:S·~~~;.~;.~:.i:· -~ ,;.;: \ \ \ oJ~~.i ~ -1 · i ___\ ___ _. Xni 1 0 ~i:.:~ '------~-----....1.------L...-----.._ {s;,·: . 300 400 so-o soo 100 aoo ~~K ~~ Wavelength, millimicrons f;,~::-;,,,;a Figure 4. Visual Response Curve of the Human Eye, Spectral Dependence ;~;{~:~~ of Luminous Flux (Reference 3) i';.il~+f;:;i~~~ii:fc:;;; ,:c"SSF!i,~2:;~RiE2;'t~r2 ;;"::!J~'ii~;Jr '''7'i?'~'I~~~:~r""· ,::o:_ - ;_~~~:~£{: • :..::>t·~?~ -:~:: -"\:_,·~?t. ~;/_ :~~ < __ § :,:,~:; .. :[~ 1~1 ((5) A 5 (exp· (hc/k ).. T) -1) where IA is the radiant flux in terms of energy per unit area per unit I time at wavelength A, emitted by a hot source at temperature T, his Planck's constant, c is the speed of light, k is Boltzmann's constant and e: is the emissivity of the flame. Typical flux-wavelength distri butions calculated from this equation are shown in Figure 5. § B ~l1 - s.. -l.MAX 0 s ~1 250 .. ·r ~ · ..- >~ ~ : :~ ISO 100 so ;~.t:: --1 V{avelength, Microns :j ;.2-:~:. i;J · ~ttrl, Figure · 5. Planck's Law: Radiance as a Function of Wavelength "lll ,_. ~··i~ for Various Temperatures \"J~. :_·_;_~--:-:··_· _._:.~_-_-.·.·.:.:_~._~ -_._~ .'... . ...., ·_.,·. It can be seen from this figure that very little of the e_nergy emitted by : ~ blackbody radiation is distributed in the wavelength band most sensitive · to the eye. Further in. order to generate an intense ~··i~ for Various Temperatures \"J~. :_·_;_~--:-:··_· _._:.~_-_-.·.·.:.:_~._~ -_._~ .'... . ...., ·_.,·. It can be seen from this figure that very little of the e_nergy emitted by : ~ blackbody radiation is distributed in the wavelength band most sensitive · to the eye. Further in. order to generate an intense source in the visible I ~--.~-~_.~·__. _:.._' .·-·~~-·.-~-~-j:.:··-·.···-~.~-~.--•_:i'::·: :::~:~~d~ti:~~ !i;:f~i~7:n~~m~t~~~u::;~~ ~~ ::::~~ t~:d f;::t~o~~~r -•. -•. ~- ; visible light energy generated out of the total radiation energy would be ·very low. >~'.J;:.t&;~gfii*%:' tti~~:~;~;~;,~~~iii~~~~,,>:'ii?:'i'iJ~k~~;;,.:,s:;''8Tti;:;;:''R7:~7"0""'"''C':~?;~I:;E _. ',JD.'E~&~;LlL • ·.::-~;-:.~?' ·;_.:.-"t,,.. :.;; ·-:.' :.:· l::~i ... ~-~-. ~:,·:: r:~i ~~ 1.2 .3 Desirable Pvrotechnic Ingredients ;_}.:;-~ . This observation leads one to recognize that pyrotechnics composed of organic fuels which have the highest heut of reaction can not be considered since these mixtures produce flames having character istics similar to blackbody emitters. This is particularly true for fuel rich compositions which have a tendency to generate significant amounts of carbon and aromatic soot particles. ,. l The radiant· e mi s ston-in -the -v-isible-ca 11 ·'he-"improved "'by-in-etudtng--' ~- .... - - -~ chemicals in the pyrotechnic mixtures that will form thermally excited ·:.(:,'!- ;.¢ reaction products capable of emitting radiation at desired wavelengths. This process can be described by the following equation, - - J A+B [C+ heat] [C* - C + hv {6) Pyrotechnic Reaction Thermally Light Components Product in Excited Emission Flame Product SpeCies Many inorganic salts exhibit this phenomena. Several elements which· react in pyrotechnic flames forming oxides, hydroxides and chlorides have been used to "color" flames. These include, strontium which pr9duce$ -a. .. xe.d;eqlor.,· har,ium,.{g.r~,~~l'-&~~:d.um~iow-~~•"n;~ .., ""' green and orange) and copper (blue to green) . Lithium (red), boron {green), thallium (green), rubidium (red) and cesium (blue) are also strong color producers but their use is not as practical because of cost, ,~s -~ toxicity or the nature of their compounds. ~r-~ j ~;~~'< The actual emitting species of these metals are known to be the di- and tri-atomic species which can exist at high temperatures in 1.1 the flame. For example, ;::.~ 4t a •. the red light produced by flares con~aining -~1~.:~~-~~ ~ strontium and a source of chlorine is a i.l ' result of SrCl emission (strong emission near 640 m!J.). In the absence of chlorine, emiss_ion has been attributed to SrO. ':~il:· } ~} ~J b. BaClz emits in the 505-535 m!J. region ~\;?.'~ The document page contains a diagram illustrating a reaction energy profile for a pyrotechnic mixture. The diagram, labeled "Figure 2. Reaction Energy Diagram," shows relative energy of formation on the y-axis and reaction path on the x-axis, depicting activation energy ($\Delta\text{H}_a$) as the energy required to initiate burning. Text labels define R as "Pyrotechnic Components (Reactants)" and P as "Combustion Products." The page also includes a numbered list of factors related to pyrotechnics and a definition of "Heat of Reaction" from section 1.2.1. There are no photographs, handwritten annotations, official stamps, or filled-in forms present on this page. The page contains a graph labeled "Figure 3. Standard Observer Curve" illustrating the human eye's relative response to different wavelengths of light, peaking in the green to yellow region. Beside the graph, there is a section heading "1.2.2 Desired Output Spectra" followed by explanatory text. The text discusses pyrotechnic compositions and their light emission in relation to human vision. There are marginal notes throughout the text, but no stamps, signatures, or handwritten annotations are clearly visible. The content is purely textual and graphical, with no visual evidence of experimental procedures or facilities. light produced by flares con~aining -~1~.:~~-~~ ~ strontium and a source of chlorine is a i.l ' result of SrCl emission (strong emission near 640 m!J.). In the absence of chlorine, emiss_ion has been attributed to SrO. ':~il:· } ~} ~J b. BaClz emits in the 505-535 m!J. region ~\;?.'~ ~ {green) •. It· c. BaO emits over a broad spectrum, 400 to 800 m!J.. 1" ~~: i\;t,} . <~~1 8 -- ~tr~tFJs:~~-~-~ -~ j;J~ -~{! d. The hydroxides of these metills also emit in the respective wavelength bands. e. MgO emits at apprcximately 500 miJ.:. 4 1. 2.4 Color Intensifiers Where possible, chlorides are added to the pyrotechnix mixtures to enhance the color of the flame. Perchlorate oxidizers contribute the minimal req·uirements without reducing the efficiency of the energy out put. In some cases it has been found that the addition of chloro organics significantly increase the color intensity. Substances such as he.xachlorethane, hexachlorobenzene, polyvinylchloride are sometimes employed for this purpose. 2. CRITERIA USED TO SELECT CANDIDATE PYROTECHNIC MIXTURES The following considerations-were ·ma-cfe in selecting candidate ,~!:1 pyrotechnic formulations 1 for the initial experimental investigations. Based ·or?- the.premis.ed desirability. of producing flames which emit . ~;~~ -~! radiation in the visible wavelength region,primary consideration has ,J ~;~~- been given to inorganic compositions. II 2.1 OXIDIZER Comprehensive literature surveys by Shock Hydrodynamics and ,j other investigators have shown that perchlorates are the most desirable iilt oxidizers. They contain a relatively high ratio of oxygen to total mole- . cular weight, their heats. or reaction with metals such as aluminum and ~i~ magnesium are significantly better than other oxidizers and they generate only oxygen as a gaseous product. Perchlorates are generally stable, i;,~ yet they are easily ignited, unlike oxidizers such as nitrates and metallic oxides. Nitrates· suffer additional disadvantag.es in that they are not as exothermic and thus tend to have a slower burning rate with fuels such -~~-E-:·<._J~ '""'.•~ as aluminum and magnesium (see Equation 4), and they generate a non §~·-~i:t ,_. reactive gaseous product, nitrogen. -""~~ ~~(1 Of the alkali perchlorates, lithium and sodium perchlorates have II the highest rates of oxygen to total molecular weight, viz., 64/106.4 and 64/127.45, respectively. However, these compounds are extremely ~hygroscopic. This characteristic decreases the storage life of a pyro technic system. The absorption of water by these oxidizers is an exo- . -~ thermic process. Because of this factor one The image displays a graph titled "Visual Response Curve of the Human Eye, Spectral Dependence of Luminous Flux." The graph plots absolute photopic luminosity in lumens per watt against wavelength in millimicrons, showing a bell-shaped curve peaking around 550 millimicrons. The y-axis is on a logarithmic scale, ranging from 10^-1 to 10^2. The x-axis ranges from 300 to 800 millimicrons. There are no photographs, handwritten annotations, signatures, stamps, forms, diagrams, tables, or other visual elements beyond the graph and its labels. the highest rates of oxygen to total molecular weight, viz., 64/106.4 and 64/127.45, respectively. However, these compounds are extremely ~hygroscopic. This characteristic decreases the storage life of a pyro technic system. The absorption of water by these oxidizers is an exo- . -~ thermic process. Because of this factor one must also be concerned •!-'•): . i~¥: ~~} with the design of special safety precautions. !!?.~~ .}'· ~~:1 .-:~ ~-~f~~ ·'\.":<;;1 9 ':~8:f}'1tit·:~i;~},'f,'f:i;i~:;~cz,(~R<f!fifl'(')[!;E'io''¥W'c%.'iii''S40'07S~:J,~~':;?:"%07S'%;??3)"{?s:- ifr:~g}}~, L.:.:~ •·· · · - · ~ - : ~ :~ . ;;Jj~:_;:~~-:.: ~.; ..-._.·~,.;;;-:,;~;.;. - -:-..~~-j _-_ · · : · ~ ~; ~~~:. - ;;..~:..:....:.. ........ ~-%'-· ~-·;.:..·;..._~.:.. .. : ,..;.:_~_: ... ..:.. =:~-.::..~ ..,.;.:: :.::.: <::. -~;; . r::--i~ -~~ ".":-..-:·};.,:,..:_;; Potassium perchlorate wus selected as a primary oxidizer for the initial candidate mixtures. ·This oxidizer hus an oxygen-total weight ratio of 64/138.55, which is somewhat lower than LiCl04 and NaCl04, however, it is a stable compound and its heat of reaction with aluminum, for example, is slightly greater than the reactions between LiC!04 or NaCl0 and aluminum. 4 2.2 FUEL COMPONENTS ,.--~ -~ It has been found that aluminum and magnesium are the best fuels %·,;_~] for use -in photoflash mixtures. The heat of reaction and peak light intensities resulting from Al/KC10 are much higher than equivalent 4 Mg/KCl04 compositions. The radiation emitted follows generally what would be expected for continuum radiation. Peak light intensities for stoichiometric mixtures of Al/KCl04 and Mg/KCl04 have been measured to be approximately 40 and 18 million candles, respectively • 7~~·) _- 2.3 CONSOLIDATION OF MIXTURE It has been shown, that the manner in which the fuel and oxidizer are incorporated in the pyrotechnic device will greatly influence its · performance. 5 Consolidated compositions contain binders, usually .. ,organic~y..m.ei'.$~ -¥Jbich...farm..a...r.i.g,i.l:L.ar semi:-dg:id.~_l'ba_c.ons.oU::. ... ------- dated composition however is a burning system which has a relatively large spatial separation between fuel and oxidizer. Thus, the burning •t.t) 1:i rates are relatively slower than a comparative non-consolidated system. il;t;.: II Non-consolidated systems under confinement usually have higher deflagration rates than consolidated systems and the intensity of the emitted light is greater. Most photoflash systems are thus non- consolidated, and this type of system was selected for these studies. ~} 2.4 OUTPUT IMPROVEMENT (SELECTION OF STANDARD MIXTURE) :<~;;x~ A standard photoflash composition, III-A, was selected as a reference. The composition of this mixture is shown in Table I. The [~·~i. addition greater. Most photoflash systems are thus non- consolidated, and this type of system was selected for these studies. ~} 2.4 OUTPUT IMPROVEMENT (SELECTION OF STANDARD MIXTURE) :<~;;x~ A standard photoflash composition, III-A, was selected as a reference. The composition of this mixture is shown in Table I. The [~·~i. addition of barium nitrate to this mixture increases the radiation output I ~~ I ~~ . ,. in the visible spectrum over that of the basic Al/KCao 4 mixture. As discussed in a previous section, the BaO and BaClz formed in the burning processes emits strongly in the wavelength region most sensitive to the fH eye. 2.4.1 Mixture "D" :t<:r. -~ During the Korean conflictS an experimental photoflash mixture having a very high fuel to oxidant ratio was developed having a peak - :frrt~S~~P32Siiiz:ii..·~~--:v :.;:._$ .:. ·" ~ ">:':1 ""-'::-';~ --~~ .::ii: TABLE I. CHAR!~CTERISTICS OF TYPE Ill PHOTOFI.J\SH COMPOSITION 6 Ingredients Specification Microns Percent Aluminum, atomized ]AN-A-289 15 40 Potassium Perchlorate PA-PD-254 24 30 Barium Nitrate PA-PD-253 147 30 PHYSICO-CHEMICAL DATA: Heat of Reaction, cal/g-2774 (calc) Reaction Temperature, 0G-approx. 3500 Gas Volume, cc/g-24 (calc) Tapped-1.67 Vac. Stab, 120°C, cc gas/40 hrs-0 .16 SENSITIVITY DATA: Impact: PA, inches-40 + Friction Pend: Steel-Crackles; Fiber-No Action Ignition Temp, oc: 5 sec value-610; 'DTA-No Ignition Hygroscopicity: 57% RH, room temp; ,Hrs 24; % Wt Gain < 0. 1 Electrostatic Sensitivity: Joule, Min 2 .14; 50% Pt-3. 5; 100% Pt-4.5; T~mp-650f; % RH-40: Unconfined-Yes - -~.:;:,/'-<,; -. ;.;;; .. .. _.;_ i.;.:~.} -~-:~2~~ :.:.~ ~-;..;~~: -·~·.:~·.:·..:.:-~.--.~- ....... \ . :h~U~ h1Il light output twice that of the Type III mixture. This mixture consisted of 70% Al/30% KCI04. A further improvement in performance is anticipated by replacing a portion of the KCl04 oxidizer with Bu(N03) which will 2 ~lt act as an oxidizer and color enhuncer (see Table II for compositions of candidate pyrotechnic mixtures). §~;~ ~ TABLE II Pyro* Arbitra__ry Type Designation c Composition A B ·D Designation Ingredients % % % % Al . 40 .50 25 70 KC10 30 40 30 20 4 - Ba(N0 ) 30 10 10 3 2 CaSi 10 1::~r 1~ ' Mg . :.- ... 35 ~ . TOTAL 100 100 100 100 'l"-c· .• ~··.~ *All mixtures prepared in accordance with PA-PD-267. ~nL~ TYPE A Follow.s the formulation given in PA-PD-267 for J ·~-,,~. Type III Class A (Fir.e Oxidizers). ~~;'~ TYPES B, C, & D follows The document page features a scientific graph, labeled "Figure 5. Planck's Law: Radiance as a Function of Wavelength for Various Temperatures." The graph plots radiant flux density against wavelength for different temperatures, illustrating blackbody radiation curves. Above the graph, a mathematical equation for radiant flux intensity is presented. Text below the graph describes the implications of the plotted data regarding the efficiency of visible light generation from blackbody radiation. There are no images of people, locations, equipment, or subjects, nor any handwritten annotations, signatures, or official stamps. The document page is primarily text-heavy, focusing on technical information related to pyrotechnic ingredients and their light-emitting properties. Visually, the page features a section number "1.2.3" and the title "Desirable Pyrotechnic Ingredients." Below this, a chemical equation is presented in a box, illustrating the process of light emission. Scattered throughout the text are a few small, dark marks that could be ink blots or possibly minor damage to the paper. The right margin contains a parenthetical numeral "(6)," likely referring to the equation. At the bottom center of the page, the number "8" is visible, indicating the page number. There are no photographs, stamps, or handwritten annotations present on this particular page. 1::~r 1~ ' Mg . :.- ... 35 ~ . TOTAL 100 100 100 100 'l"-c· .• ~··.~ *All mixtures prepared in accordance with PA-PD-267. ~nL~ TYPE A Follow.s the formulation given in PA-PD-267 for J ·~-,,~. Type III Class A (Fir.e Oxidizers). ~~;'~ TYPES B, C, & D follows the same guidelines including ~~·~ particle size given in PA-PD-26 7 • ......... :. ...· .~-~~ ~l1~ . ... ~i~~~ ~ ~~-· - 12 ~:r.:~Jr];;:i:t: ~c~.- ,:t~~(~;:ri ;.:-_;-:·.;:;.;;_ 2.4.2 Mixture "B" The addition of calcium silicide should have two effects on the basic Al/KC10 reaction: 4 1. Because of the exothermic nature of CaSi in an oxidizing environment, the heat of reaction of vc·', -~ this mix should be greater than the selected reference-(i.e ... .,. .. .mixture A).~.-'Ihis inc.r.e?J.se . .in~. the h