This report covers work done by the Physical Chemistry Group and the Pile Engineering Groups. Subjects covered are as follows: corrosion laboratory testing details; pile borescopic inspections; slug deformation details; Van Stone flange corrosion details; corrosion rate at elevated temperature; added control ink facility; borescope equipment and repair; water recirculation cooling tests; pile expansion; carbon dioxide experiment; special graphite measurements; graphite core sample; vertical thimble temperature; beta experiment; x-ray diffraction studies; thermal annealing; empty process tube temperatures; oxidation of graphite; thermal annealing -- interferometer measurements.

Activities for the month of February are as follows: (1) calculations of reactivity and temperature limits; (2) calculations of operating levels of D pile if reduced in size; (3) symposium on power coefficients; (4) test of new vertical (safety) rods; (4) metal quality studies; (5) status of process tube ionization chamber failures; (6) reactivity balance of each of operating piles; (7) graphite testing; (8) water activity calculations; (9) pile shielding; (10) radioactivity of titanium; and (11) critical mass experiments.

Activities covered in this report for the month of January are as follows: (1) power coefficient test of the F Pile; (2) control rod calibration; (3) investigations into reactivity gains possible by zoning the pile for metal charging; (4) polonium production under emergency conditions: (5) analysis of process tube ion chamber failures; (6) measurements of the thermal neutron flux in various pockets of the E Test Hole of the F Pile; (7) reactivity balance of each of the operating piles at beginning and end of this report period; (8) graphite studies; (9) pile shielding; (10) radiation measurements on a simulated D-R rod guide and rod; and (11) calculation of radioactive isotopes expected in cooling water.

The pile physics group reports on reactivity power coefficients from the production test No. 105-248-P, the water leak in B pile, graphite properties, xenon equations from the B pile shutdown of March 1946, and reactivity balance. The experimental physics group headed by J.M. West reports on graphite testing, the P-11 project, and shielding. The experimental physics group headed by E.B. Montgomery reports on diffusion length measurements in the DR and H piles. (GHH)

Work of the pile physics and experimental physics groups is reported. Theoretical work is also reported.

This report contains brief summaries of activities at the Hanford production reactors for the month of Oct. The activities for the Pile Physics Group are: (1) H Area start-up; (2) outlet temperature recording systems; (3) reactivity balance for each pile for this period. Activities for the Experimental Physics Group are: (1) graphite testing; (2) 305 testing -- P-slug standardization and graphite standards; (3) shielding. Also status is given on critical mass project.

This monthly report details 100 Area technical activities of the Physics Group for the month of August 1949.

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On July 14, 1949, and office memorandum was written about operations of a reprocessing building on the Hanford Site being suspended due to the mishandling of some plutonium powder. The letter describes the process of decontamination of the building surfaces, and the ventilation of the rooms of that building. It also describes the problem with the ventilation fans due to increased temperature and pressures.

This report is a descriptive journey of the Activation Analysis of the Rare Earths.

Experimental results on the adsorption of U from solutions by activated C indicate that low pH values reduce the adsorption and that a marked change occurs in the adsorption of U(VI) at pH2. Under a given set of conditions the adsorption of U follows a typical Freundlich isotherm. The particle size of the charcoal affects the rate of adsorption but not the amount of U adsorbed at equilibrium. The temperature coefficient of adsorption is negligible, and the adsorption of U from uranyl solutions is a reversible process. (BJH)

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Some time ago we started work in an attempt to observe alpha-particle decay in isotopes of atomic number less than 83. In the first experiments, thin targets of gold leaf were bombarded with 190-Mev deuterons in the 184-inch cyclotron. Two alpha-decay periods were observed in these targets; one of 0.7 minutes half-life and another of 4.3 minutes half-life. The alpha-particle energies were 5.7 and 5.2 Mev, respectively. Chemical separations proved that the 4.3-minute period is due to a gold isotope and suggested that the 0.7-minute period is due to a mercury isotope. The mass numbers of these new isotopes have not been determined. However, the results of excitation-functions in the production of the gold isotope by bombarding gold and platinum with protons suggest that its mass number lies in the range 185-188. The work on this isotope indicates that the alpha to electron capture branching ratio is of the order of magnitude of 10{sup -4}, and that positron activity accompanies the 4.3-minute alpha-period.

This is a report on Analytical Services of the Pile Area Laboratories at Hanford. Pertinent facts are listed regarding the analytical services currently provided by the Analytical Section in the pile areas. The work of the Analytical Section in the pile areas may be classified into five categories as follows: Analysis of pile process water, analysis of power plant (boiler) waters, analysis of drinking water, analysis of columbia (non-process) and Yakima River water, and preparation of reagents and standard solutions.

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About four-fifths of the energy of the fission process is shared by the two heavy fragments into which the nucleus splits. This energy, of about 80 Mev. per fragment, is transferred to the medium in which the fission takes place in two ways. First, because each fragment is stripped of about half of its electrons during most of its path, it will interact strongly with electrons and thus lose energy through ionizing collisions with other atoms. Secondly, the fragments will lose energy by elastic collisions with atoms as a whole. Each fragment leaves in its wake a cloud of moving electrons and atoms. This cloud will roughly resemble a cylinder whose radius will increase with time on account of the motion of the struck electrons and atoms. They may now investigate two features of the slowing down process. First as it affects the fragment, i.e. we calculate its range, straggling, etc. And secondly they may work out the motion of the cylinder of moving particles, its effect on the medium, etc.

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This semiannual report includes references in future items in the Brookhaven National Labratory program as well as an account of progress in the post six months.

This is a progress report from Brookhaven National Laboratory for the period July 1 through December 31, 1949.

The constant temperature bath is in operation. A ballistic type instability was detected in the calorimeter circuits and corrected by grounding the bath. Calorimeters 37, 39, 40, and 43 have been installed are now being run. Calorimeter 40 was found to be unstable, and is to be disassembled and examined for the trouble. Calorimeter 46 was finished and placed in operation. Construction details are discussed. Six Logac samples were run in Calorimeter 38. Tests of this calorimeter are in Table 1. Comparison of Calorimeter 38 in a water bath and in an ice bath is shown in Table 2. Good results were obtained for such a drastic change in environment. Calorimeter 38 was turned over to Calorimetric Assay marking the end of the tests of this particular microcalorimeter. Calorimeter 44 was completed and installed in the ice bath. Table 4 shows the results of tests. The zero bridge potential is small and is very stable compared to Calorimeter 38. The comparison of the values with those from Calorimetric Assay is summarized in Table 3. The characteristics of Calorimeter 44 are shown in Table 5. Construction details are given for the platinum-manganin bridge-type thermometer. An instrument was needed that could be …

The cyclotron is the only practical source of many carrier-free radioisotopes. The preparation and radiochemical isolation of a number of these activities, produced in the 60-inch cyclotron of Crocker Laboratory, will be presented in this paper and in subsequent papers of this series. In most cases the carrier-free radioisotopes were prepared for use in biological systems and the final preparations were in the form of isotonic saline solutions at a range of pH from 5 to 8. The present paper reports the radiochemical isolation of carrier-free Sn{sup 113} and In{sup 114} produced by bombarding cadmium with 38 Mev alpha-particles. At this energy, Sn{sup 113} and In{sup 114} are produced in a thick target by the nuclear reactions; Cd{sup 110}({alpha},n)Sn{sup 113}, Cd{sup 111}({alpha},2n)Sn{sup 113}, Cd{sup 112}({alpha},3n)Sn{sup 113}, Cd{sup 111}({alpha},p)In{sup 114}, Cd{sup 112}({alpha},pn) In{sup 114}. The shorter-lived tin and indium activities together with the possible radioisotopes of silver produced by (n,p) reactions, were allowed to decay out prior to the chemical separations.

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