This report discusses the following topics: (1) radium separation from K-65 residues - laboratory scale; (2) fractional crystallization studies barium - radium; (3) the concentration of radium from barium rich mixtures; (4) the coprecipitation of lead and radium sulfate; (5) the separation of radium and barium by ion-exchange; (6) engineering work on separation of radium from K-65 residues; (7) silica removal, corrosion tests; (8) radon counting; (9) the design of equipment for the measurements of radon in breath and air samples; and (10) proportional counting of radioactive gas.

The extraction of radium from uranium residues was proposed either by the use of the old (Curie) process or by the development and use of a new process. Qualitative procedures for the extraction of radium from pitch-blende are found recorded in the literature but little quantitative data are available. In order to become acquainted with the process and techniques involved, an attempt was made to use the method developed by the Curies, which essentially is being used by the Eldorado Gold Mines, Limited, Port Hope, Ontario.

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Certain laboratory processes require low-powered radio-frequency heating with fine continuous control. A lightweight low-powered induction heater which is capable of delivering about 20 watts of power into a load 12 feet from the heater with fair efficiency was developed to meet this need.

Part of the design and development work connected with the erection of the chemistry "cave" in the "GP" Building entailed an investigation of various protective measures for materials of construction. This work was based on the observations and recommendations of personnel engaged in work at a similar installation at Argonne National Laboratory.

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Investigation of the physical and chemical properties of polonium important to its behavior and for the improvement of the quantity and quality produced is being continued. A sample of polonium is approximatelyf 1 x 10{sup 9} disintegrations per minute was counted in a Logac for 250 days in order to determine the half life. A statistical treatment of the results gave a half life of 138.3562 {+-} 0.446 days. Combined with previous calorimetric determinations a new grand mean of 138.3975 {+-} 0.0091 days resulted. The wavelengths of 138 lines appearing in the spark spectrum between 3050A and 3463A (Region 4) have been tentatively assigned to polonium and have a probable error of less than 0.02A. Thirty six lines in Region 6 (4225A to 5675A) tentatively assigned to polonium have a probable error of less than D D6A. A measurement of the resistivity of polonium has given a value of about 95 microohm centimeters, and although the Hall voltage could not be measured with much precision, it was possible to set a maximum value of 0.03 millivolt. These values indicate the polonium is a metallic conductor rather than a semiconductor. A rugged but compact gauge made of stainless steel with a …

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The efficient prosecution of the research and process development on polonium, radium, actinium, waste disposal, and alpha-neutron sources requires the use of a wide variety of instrumental techniques such as: alpha, beta, gamma, and neutron counters and survey meters; emission, absorption, and mass spectroscopy: x-ray and electron diffraction; microbalances; and calorimeters. The complex and kaleidoscopic aspects of our research program require; (1) The application of standard instruments and techniques to a variety of problems; (2) The development of new techniques for the use of standard instruments; and (3) The development of new or improved Instruments. The sum of the above three categories constitutes the field of supporting research. The amplifier for counting pulses of wide dynamic range which was developed for counting beta particles in the presence of alphas has operated so satisfactorily that it has been decided to attempt to adopt it for neutron counting. Substantial improvement at medium counting rates has already been obtained but results at high counting rates are not as satisfactory. The development of a survey meter for monitoring fast neutrons has been under way for sometime. The attainment of higher efficiency has been attempted by the use of a dual-chambered counter tube. The tube …

One method suggested for soldering small beads to fine wires using a torch to heat the bead, flux, and magnesia brick did not prove entirely satisfactory in this case. It was found the brick would draw heat away from the bead and flux at too fast a rate resulting in a poor weld, a rough surface, and an excessive accumulation of flux on the bead. Secondly, removal of the depleted flux presented a problem when the welding was done on the surface of the brick.

The thermal conductivity of the gradient medium plays a very important part in the development of a calorimeter. It is a large factor in determining the sensitivity. The thermal conductivity apparatus was built primarily to find out why the measured sensitivities of the microcalorimeters were so much smaller than the calculated values. This question haa been resolved. The apparatus is now being used to study the thermal conductivity of Santocel, a granular insulating material produced by Monsanto Chemical Company. The Interesting fact is that though this material is in the solid phase it has a lower thermal conductivity than air. In a previous quarterly report approximate evidence was submitted to show that Santocel A has a lower conductivity than air at room temperatures. This result was worth verification, since this material would then prove useful in the construction of microcalorimeters. A verification is submitted in this report.

Research on polonium chemistry and physics is being continued on a reduced scale. Those problems which have direct bearing on the preparation of the metal and those which will lead to a better understanding of any phenomenon encountered are being continued. Data from the calorimetric measurements of polonium on Calorimeters 39 and 46 were treated by the method of least squares to give a grand mean half life of polonium equal to 138.3993 {+-} 0.0093 days (1-13). New apparatus has been constructed for the measurement of the vapor pressure of polonium and its compounds in the low and the high temperature ranges. Technical difficulties have delayed the actual collection of data (1-22). The constant current magnet to be used for the measurement of the Hall effect of polonium has been tested and found satisfactory. A device utilizing nuclear magnetic resonance absorption for determining field strength has been constructed on a preliminary basis (1-24). A total of 208 lines in the ultraviolet region between 3200 A and 1900 A have been measured with an error of less than {+-}0.02 A (1-28). Studies on the X-ray and spark spectra of polonium and its compounds have been conducted. A preliminary study by X-ray …

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Neutrons produced by 350 Mev protons impinging on beryllium are scattered by hydrogen. We measure the differential scattering cross section as a function of the scattering angle. Results are summarized in Fig. 3 of the paper.

An experiment is described in which an attempt is made to follow the path of oxygen in photosynthesis by the use of O{sup 18} as a tracer.

Since the end of the war when the long-lived isotope of carbon, C{sup 14} became available a new tool has been applied in the study of photosynthesis. Because of the interest evoked by the tracer method, research in all areas of photosynthesis has expanded. There have been reviews on various aspects of photosynthesis such as the primary photochemical reaction, quantum efficiency products, and comparative biochemistry, many discussions of which were included in the monograph of The American Society of Plant Physiologists, ''Photosynthesis in Plants''.