Das, Sushil K

Mukherjee, J

Sandell, Prabir K

English

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jH e ite tA  to  t k e  £ d i t o tThe Board o f  Editors does not hold itself responsible fo r  opinions expressed in  the lelten  published in  this section. The notes containing short reports o f  original investigations commu^ nicated to (hU section should not contain m any figures and should not exceed 500 words in  length. The contributions reaching the Secretary by the 15th o f  any month m ay he expected  to appear in the issue fo r  the next month. N o proof w ill be sent to the author.15X -R A Y  A N A LY SIS OF R A D IO A C T IV E  FA LLO U T OVER C A L C U T T APHABTR K. SANDELl., J. MUKHEIUEE a n d  SUSHTL K. DASDepartment of rjiY.sic,s, JAOAvrrp I ’nivkusity, (\\L( nTT\-32 (Received, Sejdember 9, 1903)Since 1961, the radioactive fallout ov'^ er Oaleutta has been systematicallycolloctcd and studied in our laboratory. Tiu' samjdc's won' ffenerally classifieflIaFig. I, X-ray Spor*tnim of Sample—A,at 36Kv, 24mA. Scale factor —  X 8 between O'" to 24®X 64 between 24® to 43°X 8 between 43° to 75®2$ Scans. Time constant—4,376Letter to the Editor 377>575 70 r>r>«  <uU. luS( alo factor(JO ru> 50 45 40 35 30 25 20Kig. 2. X-ray Spoctruin of SampU'.—B, at 30Kv, 24mA.X- 8 hctwoon lO'’ to  75°20 S(taii. Thu(^  fonstaiit— 4-15 10into three groups. Tlie first Oroiip 1 (sample* A) (jonsisted of air-liorne particles (le])osited in an (uianudled tray siu(*ared with glycerine, on dry rainless days. During rainy days, ho we v’er, tile rainhorne dust was coll(*(dt*d along with rain- Avat(*r in an empty tray. The w'at(‘r was filter(*d. tin* insoluble* residue forming the* material lor Group 2 (»Sample H). Tlie filtrate was finally i’vaporated to dryness, yielding working material for (houp II (sample C). The sanifiles were se])arately powder(*d in an agate* niewtar and pn*ss(*d into pills eif apprei priate* sizes.VtfScale factor 2& Scan,- X 8 between 10° to 75°Time constaeit—4.Tlie X-ray spectrographic analyses were carried out with a plane crystal cpiartz X-ray spectograph whose analytical range extends from Ti (At. No. 22) upwards. An appropriate idea of the distribution ot the heavy and light elements was obtained by varying the high tension applied to the X-ray tube. The X-ray378 Letter to the EditorBpt'ctra of the samples A, B, and 0, so obtained, were compared with standard curves of the following elements, Ni, Cu, Fe, Mn, Bi and Au. under the same parametric conditions for 26 calibration. To detect the presen(ie of recognisable (piantities of Uranium, all the spectra w'(>re compared to the sp('ctnun of a uraninite mineral sample.The graphs A, B and 0 represent the spectra of the respective grouj) samples taken at I16KV and 24MA. The spectra have been crosschecked in evc^ ry case with those taken at 20 KV. 24MA. The (iements identified ar(! talndated sample-wise in Table I.It may l>e noted that Pb and W ]>eaks are ])res(‘nt in all the graphs. Pn*- sumably the VV lines owe their origin to the of Hardtack test or scatterings of the incident beam, while the Pb lin(‘s could also be due to the presence of lead lining of the samj)l(^  holder.TABLE 1Sample A : dry fallout'An, Vo, Cti, Th, .Mn, Ni, Au. Hi, Kb. Sr. Yb, Ha.Sample H : Zu, Fc, Cu. iMn. Sr, Ni, .\u. Hi, Rb, Itu, V'b.Hesidue from rain- borne fallout.Sample C :Water soluble salts from rainborno fall-out.Zn, tv, (!u, Sr, Ni, Mu, Hi, Au. Yl».In sample‘A’(dry fallout). Zn. Ou. Fe, and Sn are present in much greater (piantities than in sample ’B', filtered as rain-borne fall-(»ut. Th is present only in sample A. It may be noted that Zn pn‘dominala‘S as a w^ ati'r soluble salt, while Ba and Fe predominate in insolubli^  form. Tin* pri'si'mic of large quantities of Fe, Zn and Mn have also been corroborated by chemical analysis.We are indebted to Prof. 8.1). Chatterjee for his active interest and guidance in the work.

X-Ray Analysis of Radioactive Fallout Over Calcutta

http://arxiv.iacs.res.in:8080/jspui/bitstream/10821/2365/1/X-rays%20analysis_Prabir%20K%20Sandel%20J%20Mukerjee.pdf

X-Ray Analysis of Radioactive Fallout Over Calcutta

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