The dark fixation of carbon dioxide by green algae has been investigated and found to be closely related to photosynthesis fixation. By illumination in the absence of carbon dioxide followed by treatment with radioactive carbon dioxide in the dark, the amount fixed has been increased ten to twenty fold. This rate of maximum fixation approaches photosynthesis maximum rates. The majority of the radioactive products formed under these conditions have been identified and isolated and the distribution of labeled carbon determined. From these results a tentative scheme for the mechanism of photosynthesis is set forth.

This monthly progress report covers the following programs: (1) 184-inch Cyclotron; (2) 60-inch Cyclotron; (3) Synchrotron; (4) Linear Accelerator; (5) Experimental Physics; (6) Theoretical Physics; (7) Chemistry; (8) Medical Physics; and (9) Health Physics and Chemistry.

Quantities of the order of ten million to 100 million radioactive particles per month were emitted from the stacks over a period of several months. High activity in the range 0.1 to 3..mu..c was probably confined to large carrier particles of corrosion debris from iron ductwork in the separations plant ventilation air system. This report discusses chemical, physical and radiochemical properties of the particles, and possible biological and health effects of exposure to them. (ACR)

This report summarizes the contamination observed at the Hanford Works and vicinity for the period October, November, and December, 1947. Trend charts showing trend of contamination for the various sampling locations are only included where a true trend can be established for the three month period; a thorough analysis of all trends will be considered in detail in the annual report from this section. The report is divided into the following topic sections: Meteorological -- dissolving data; beta contamination in the air and the radiation levels in air; alpha and beta contamination in the Columbia River; beta contamination in the rain and snow; alpha and beta contamination in drinking water; beta contamination on vegetation; and alpha and beta contamination in Hanford Wastes. An appraisal and review of all the results is considered in detail for each section. Statistical analysis is used whenever possible to determine significant values and differences in levels of contamination measured.

Records show that difficulty has been encountered with the discharge of two tubes in B Pile, twelve in the D Pile, and fifteen in the F Pile during the period from initial start-up until March 15, 1948. In sixteen cases the tubes have been replaced, six of the tubes which were in the fringe have been made air tubes, four did not warrant replacement, and three are to be replaced in the future. General statistics for these twenty-nine tubes are presented with additional details in this report.

An investigation of the assimilation, distribution, retention, an excretion of the fission products and actinide elements in the rat has been conducted at the Crocker Radiation Laboratory, University of California, Berkeley, California. These studies were initiated October 15, 1942, and are continuing at the present time. An extensive survey has been made of the metabolism of twenty-two different radio elements in the rat.

A test dose of Zr{sup 95} was given to a female patient which had a metastatic reticula endothelial tumor at the distal portion of the left femur. A comparison of the deposition of Zr{sup 95} showed greater uptake 24 hours after administration than any of the normal tissues investigated.

A procedure for making Be foils between 10{sup -5} cm. and 10{sup -3} cm. thick, and with diameters up to an inch and a half is described, and methods of mounting these foils are indicated.The problem of making thin Be foils was presented in connection with focusing the proton beam in the Berkeley Linear Accelerator, and although the foils are not now used in the accelerator, they have proved to be quite useful as thin targets, target supports, thin windows, etc. The Be was evaporated in vacuum and deposited on a metal collector plate. The problems encountered were: (1) obtaining reproducible quantities of evaporated Be; (2) stripping of Be from the collector plates; (3) preventing curl of the foils when they were stripped; and (4) mounting the foils.

This summary of the research progress meeting on March 18, 1948 covers the following topics: (1) Proton-proton scattering at 7 Mev; (2) Some animal experiments with 90 Mev neutrons; and (3) Yields of spallation products of antimony.

This summary of the research progress meeting for March 25, 1948 covers the following topics: (1) Recent n-p scattering measurements; (2) Mass measurements of mesons; and (3) Naphthalene counters.

The linear accelerator is again in operation after a shutdown fore repairs and minor changes. Radiofrequency checks of the instrument were made while the Van de Graaff was open. The vacuum of the system is now very good, the base pressure being 1.7 x 10{sup -6} mm Hg with a rate of rise of 800 s/{micro}s. Some preliminary results have been obtained on the activation of carbon with protons. The experiments were done using 10 mil, 50 mg/cm{sup 2} polystyrene discs. The activation curve obtained is shown. The break shown in the curve was found on two separate runs and it yet unexplained. In another experiment a proton induced activity in nickel was found. This had a 3.3 second half-life. Positive mesons have been detected on plates exposed in the 184-inch cyclotron with an arrangement shown schematically. The beam ws allowed to strike a 1/16 inch carbon target, and the mesons, which are bent around by the magnetic field, were detected with photographic plaes placed beneath the circulating beam. A series of experiments were done in which the plates were placed at distances varying from 1-1/2 to 3/4 inch from the beam between 1/4 inch plates of copper. The plates …

The identity and relative yields of about twenty of the radioisotopes produced by the bombardment of natural copper with 190 Mev deuterons and 380 Mev helium ions have been determined. Two previously unreported isotopes were detected: Zn{sup 62}, decaying by orbital electron capture with a 9.5-hour half-life, and Fe{sup 52}, decaying by positron emission with a 7.8-hour half-life.

Three individuals were inadvertently exposed to polonium. Activity determinations on the routine weekly urine samples submitted by the individuals revealed counts of 174, 734, and 2190 c/min/50 ml respectively. An investigation was immediately launched to determine the source of the exposure, since there was no report of a spill or accident involving active material. By the process of elimination, the time of exposure was narrowed down to a time when two of the individuals were engaged in the denitration of a polonium solution in a small kettie inside a hood when a leak developed in the kettle. The active solution was transferred from the kettle to a carboy. All three individuals were present during the transfer period. Two wore respirators, rubber gloves, and smocks over their coveralls while the third stood well behind and watched the procedure. However, it was concluded that an inhalation exposure resulted. A medical study of each case was instituted and data are summarized. No immediate toxic effects were observed. (C.H.)

None

X-ray diffraction patterns have been obtained from a sample of elemental polonium over a period of more than four half-lives. This time study was made for the purpose of determining the effect of decay upon the lattice constants and crystal structure of the element.