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Title: MOUND LABORATORY PROGRESS REPORT FOR NOVEMBER, 1963

Technical Report ·
DOI:https://doi.org/10.2172/4004883· OSTI ID:4004883

As a part of the effort to establish the vapor pressure of /sup 3/He as the international temperature scale between 0.3 and 3.2 deg K, the manometric contections from /sup 4/He to /sup 3/He are being determined. The results of a single run did not agree with the predicted values. Calculations indicated that a two to one thermal diffusion column cascade is more efficient than a three to one cascade for separation of neon isotopes. Gaseous impurities in neon were reduced from 3.40 to 0.26% by passing the impure gas through a charcoal trap at liquid nitrogen temperature. About 15 liters of gas containing 9% /sup 78/Kr and /sup 80/Kr were accumulated. Calculations to determine the shape factors for the thermal diffusion system were completed. A six-stage cascade system was converted to an eight-stage cascade system of ten hot-wire and concentric-tube columns. Prior to the conversion the sixstage system enriched natural methane to 74%. Additionally, 74% of that enriched methane product was mass 17. The concentric-tube columns completed the purification of a commercially enriched methane from 60% to over 90% /sup 13/C in the total carbon, About eight grams of the methane product were accumulated. A method was developed for fabricating threshold detectors by sealing them in copper cans. Twenty-two plutonium threshold detectors, returned because of high wipe counts, were removed from the aluminum cans; then the detectors were sealed inside copper cans by tungsten inert gas welding. The recanned threshold detectors had zero wipe counts. The erratic behavior of /sup 140/Ba- /sup 140/La was traced to a macroscopic impurity in the stock solution. A separation of this impurity by cation exchange indicated tentatively that it is stable strontium. The multiple source method for determining coincidence correction was compared with the double source method. The multiple source method offered no advantages and had the distinct disadvantages of complexity and increased working time in comparison to the double source method, The radioactive decay of /sup 208/Po and /sup 209/Po is being studied. A gamma ray at 565 kev in the /sup 208/Po spectrum may actually be two or more gamma rays arising from different spin states in the daughter nucleus, /sup 208/Bi. This premise was confirmed by a detafled study of the electron conversion spectrum of the /sup 208/Po--/sup 209/Po mixture. Conversion electrons apparentiy arise from gamma energies at 535 plus or minus 10, 565 plus or minus 10, and 595 plus or minus 10 kev. The visible absorption spectrum of polonium(IV) in hydrochloric acid was measured with a mixed isotopic source of /sup 208/Po and /sup 209/Po. An attempt to measure the visible absorption spectrum of polonium(H) in hydrochloric acid was unsuccessful. The half life of /sup 209/Po was determined in several different experiments. The most reliable data, based on a measurement of total polonium by absorption spectrophotometry and total alpha activity by gamma counting, indicated that the haif life of /sup 209/Po is 36 years. The currentiy accepted haif life value is 103 years. The half life of /sup 210/Po is being determined to the nearest minute at a 95% confidence level using gadolinium polonide. A study is being conducted on the separation of neodymium and samarium in preparation for the isolation of promethium. The study of a method for separating promethium from americium is nearly complete. Americium exists in promethium samples at a concentration of about three atom per cent. (auth)

Research Organization:
Mound Plant (MOUND), Miamisburg, OH (United States)
Sponsoring Organization:
USDOE
DOE Contract Number:
AT(33-1)-GEN-53
NSA Number:
NSA-18-021708
OSTI ID:
4004883
Report Number(s):
MLM-1178
Resource Relation:
Other Information: Orig. Receipt Date: 31-DEC-64
Country of Publication:
United States
Language:
English