/•^ /,^c>^'0- Yf^ UDDC - 796 UIITED STATES ATOMIC ENERGY COMMISSIOH ABSTRACT OF MATERIAL FOR POSSIBLE PRESENTATION TO RADIO TR/VCER CONFERENCE AT THE UNIVERSITY OF CHICAGO MARCH 3 AND 4, 1947 Dat« of Manuscript: Date Declassified: February 17, 1947 March 18, 1947 Ihis document is for official use. Its issuance does not constitute authority for declassification of classified copies of the sane or similar content and title and by the same author(s). This document has been reproduced by direct photography from copy as submitted to this office. Technical Information Division, Oak Ridge Directed Operations Oak Ridge, Tennessee X2-293-Cov«r 1 - ABSTRACT OF MATERIAL FOR POSSIBIi PRESENTATICffl TO RADIOTRACER CONFERENCE AT THE UNIVERSITY OF CHICAGO MDDC - 796 I. Materials March 3 and 4, 19A7 CLASSIFICATION CANCELLED For the Atomic Energy Commiasion 3'-/^-'^^ m&^ A. BaC-^Oj from Ca(N03)g Declassification Off icojj^; - ' A brief discussion of probable quality of this product from the stand- point of radiopurity and specific activity will be presented. It will be pointed out that the only radioisotopes produced In this prepara- tion (the source of C-^ for the next several months) are Ca^*, A^*^^ and C^. Ca^5 ig non-volatile and a3'7 is not trapped by alkali nor precipitated by Ba'*'*. The C-^ appears quantitatively as C^^2 ^^"^ therefore is volatilized, trapped in alkali, and precipitated as BaC-^O'j. (No effort is being inade at the moicent to push the recovery and marketing of Can-^ (iue to its low specific activity.) Argon^" is being distributed locked jflp in crystals of Ca salts. The C^ produced from CaCNOj) bombardment at Clinton Laboratories should have a specific activity of the order of 50-100 uo C-^/mg C (^-156 C^/Cl2). B. BaC-^03 from 303^2 The average over-all specific activity obtained if all of the C"^ froB irradiated Be^Kg is converted to BaCO-j will be of •Uie order of * ^c C^/mg C. Of course the specific activity obtainable is a function of: (a) the amount of C^2 present in the nitride originally; (b) the time of bombardment; and (0) the power level of the bonfcardment. These points sill not be discussed further. The specific activity of alkaH-volatile, acid volatile, and non- volatile but oxidixable fractions will be presented if the work is completed in time. C. Other C"^ - containing oogyoimds from 803^2 Work is in progress to determine the dlstjribution of C"^ between the various fractions and probable groups of fractions as follows; 1. Alkali volatile fraction (65SK of total) a. CO «The actual value for specific activity is not yet available but will come out of current experiments. 12-293-P2-''" ^"fense of "the ::^'^* . 2 . MDDC - 796 b. Hydrocarbons (1) Saturated (2) Ilnsaturated 2. Aold volatile ffactione (about 5jt of total) a. CO2 b. HCH 3. Non- volatile, oxidlzable (30JE of total) Probably little if any work will be done in atteapting to identify the coiqxjnents of this fraction by the time of Hbe meeting. II. Techniquee A. For filtering and counting BaC'^03* A alurry of BaC03 in Ba(0H)2 is run throu^ a porcelain filter disk held between two nxbber gaskets. (The disk is made hj cutting off all but a few milllmetexs of the top of a Selas filtering crucible.) After rinsing with water and acetone, the apparatus is disassembled az^ the filter disk with its cake of carbonate is dried and welj^ed. The disk is then aounted in a metal holder iriiieb fixes its position in a standard counter hotising. Counting is done with a mloa-window tube (2.2 to 2.7 agfo/Go^ window thickness). This counting is thiok- saiqple counting since sufficient carrier is added to give a BaC03 precipitate of approximately 25 mga/oia^. Samples are then corrected for self -absorption to a standard weight of 25 ogn/cn^. This correc- tion is usually small in magnitude and of course yields relative rather than absolute counts. idvantages of this method are its speed and ease of opetration. the ohief disadvantage is its lack of precision since the filter diska are not standard in area> height of rim, angle of rim, etc. Counts on replicate samples agree within a few percent. B. For continuous mor^itorlnf: of a e^a stream containing C^ compounds An ionization chainber was inserted as one unit In the gas train used for studying the volatile C^ compounds which could be swept out of Be3N2 and Ca(N03)2 solutions. The dried gas stream was led directly ♦This apparatus and its operation is similar to that described by Henrlques et al. ; Ind. £ng. Chem., Anal. £d. 18> 349, 1946. T-J-'^^W 12-293-p3-*« UNIVERSITY OF FLORIDA 3 - 3 1262 08910 9713 MDDC - 796 throu^ the iqolsatlon cbeinber, and the current flow troa the chaniber was anpllfied in a Beckoan microaiDmeter, The Beokaan in turn drove a Uioroioax recorder. The sensitivity of this apparatus was such that about 0.1 jac of C^ in the ohanber gave fall aeale (10 inches) deflec- tion on the most seneitlve scale. This apparatus was extremely useful In determining how long to run an aeratioHi in studying the effloieooy of trapping agents and apparajtus, and in detecting unesqpeeted activities (auoh ae the presence of A^ from irradiated Ca(N03)2). fe^;/, D. 5. Anthony February 17, 19^7 Distribution: l"?. J. R. Coe, for Declassification 8. G. E. Boyd 9. W. E. Cohn 10. C. J. Collins 11-14. D. S. Anthoiqr ■a«aa«j(E-.ii l2-293-pH-bu-f Inat