The most important source of radioactivity at the exit manifold of the pile will be due to O19, formed by neutron absorption of O18. A recent measurement of Fermi and Weil permits to estimate that it will be safe to stay about 80 minutes daily close to the exit manifolds without any shield. Estimates are given for the radioactivities from other sources -- both in the neighborhood and farther away from the pile.

Report discussing progress made in metallurgy by the Ames Laboratory during the the term from October 1, 1950 to March 31, 1951.

From abstract: "The following report presents a summary of operating experience with decelerating receivers for ion beam reception. Sample calculations for design of such a receiver for the isotopes of lithium are presented. Estimates of maximum production and requirements to attain such production are given. The maximum ion beam envisioned is 17 amperes obtained from extrapolation of experimental results."

Report discussing specifications for the design of a waste heat steam boiler "for the purpose of generating steam to operate a condensing steam turbine electric generator from the clean hot radioactive air that has cooled the atomic energy reactor of [a] laboratory under a pressure less than atmospheric."

The following report covers the literature available in the Battelle library as well as the Atomic Energy Commission (New York, N.Y.) on the processing of monazite sands for thorium and rare earth contents.

In a discussion about design of cyclotron resonators, the suggestion has been made that a wide range variable-frequency system might be constructed with two coupled resonant circuits. It also would present the possibility of tuning without the switching of high-current contacts, a troublesome item now commonly used for cyclotrons. One of the circuits would be the dee and its stem which might, or might not, be tuned. The second circuit could be located out of the magnet gap in a region where more space is usually available. Tuning could be accomplished by variation of the coupling between the two circuits and/or by, say, variable capacitance of the tuned, or tunable, circuit.

Since the end of the last century (Tarknow, 1896) radiation effect o the nervous tissue has been studied in experimental animals and humans by numerous investigators, using mostly pathomorphological changes as a parameter of radiosensitivity . With increasing time intervals following radiation, pathomorphological changes are more evident, which has been known for quite some time.

Numerous studies on the effects of radiation on the central nervous system used traditional pathomorphological changes as parameters of radiosensitivity, but pathogenesis and mechanisms of radiation injury to the nervous tissue are still little understood. Furthermore, the great discrepancy of dose requirement leading to physiological responses and on the other hand to pathomorphological changes in the central nervous system is not satisfactorily explained.

"This is the fourth Quarterly Report on Task II dealing with Methods Development for Radio-Tracing of Coal Product Hydrocarbons With Tritium. The problem of radio-chemical purity of traces is resolved by developing a new method of labeling with tritium that generates essentially no highly tagged side products or impurities."

"An investigation of the chemical effects of 1-Mev electrons on BrF3 at 25 degrees C has been carried out. Pressure measurements taken during the irradiation suggest the presence of Br2 and BrF5 as decomposition products and a fractional distillation of the irradiated liquid confirmed their presence. The extent of decomposition was determined both by fraction distillation and spectrophotometric methods. The radiation effect seemed to reach saturation when approximately 10 per cent of the BrF3 was destroyed. The exposure necessary for the decomposition products to reach a concentration of half the saturated value was calculated to be 2.7 microampere hours/cc BrF3 while the "G" value was found to be 1.5. A qualitative comparison of irradiation dosages from the Statiltron with that expected from spent fuels revealed that little decomposition of BrF3 reagent is to be expected from 1-say cooled Hanford fuel (in pile for 100 days) while in the case of 1-day cooled MTR type fuel (in pile for 12 days) a saturated effect might be realized in 1-3 hours. Since at most only 10 per cent of the BrF3 is destroyed it is concluded that BrF3, from a radiation resistance standpoint, is a suitable standpoint, is a suitable reagent for …

Abstract: Exceedingly pure uranium tetrachloride was prepared for use in determining the physical constants of the compound. Measurements were obtained of the melting point and boiling point at pressures ranging from the triple point pressure to atmospheric pressure. Calculations were made of the vapor pressure equation for the liquid, the heat of evaporation, molar boiling point elevation, the vapor pressure equation for the solid, and the critical temperature.

"The effect of a single vacuum sublimation of contaminated uranium tetrachloride, with fractional condensation of the vapors, was investigated to determine whether a high degree of purity would result. It was found that this procedure was an excellent and simple method for obtaining exceedingly pure uranium tetrachloride."

The spectrum of the mono-energetic neutron transport operator for a homogeneous sphere where the neutrons are scattered with spherical symmetry in the laboratory system is considered.

"The grafting of methacrylic acid, styrene (2: 1 mole ratio) co-monomer mixture on polypropylene film and fabric, was studied to compare electron accelerators and isotopes as sources of radiation. An aluminum block that contalns i/8-in.-deep pockets covered with Mylar film for holding sample and monomer during mutual irradiatlon was developed. A preliminary comparison was made in post grafting polypropylene film and fabric preirradiated with Cow and with an electron accelerator source. It was found that post grafting was rapid at 80 ts C but slow at room temperature. Monomer equilibration before irradiation increased the grafting rate. Higher grafts were obtained when samples were irradiated in sparged and sealed containers. The grafting rate increased as dose rate decreased."

Fillerwelding is a fusion welding process that provides for the automatic addition of controlled amounts of fillerwire during inert-gas-shielded tungsten-arc welding. Fillerwelding aluminum jacketed fuel elements has been successfully demonstrated and is being used on a routine basis. This manual was written to provide the necessary information to operate and maintain the fillerweld equipment.

This note is concerned with the numerical integration of the integrals of the form anti l*SUB infinity/*SUP infinity/ f(x) *phi/(x) dx is "smooth."

This is the fifty-fourth progress report of the Laboratory for Nuclear Science at the Massachusetts Institute of Technology. Progress reported covers the period for Physics and Chemistry through April 30,1959. Progress is reported on: (1) Chemistry of the fission elements group, (2) Nuclear chemistry (inorganic) group, (3) Nuclear chemistry (organic) group, (4) Cosmic ray group, (5) High energy accelerator physics group, (6) Bubble chamber group, (7) Liner acceleratory group, (8) Rockefeller generator group, (9) ONR generator group, (8) Radioactivity group, (9) Cyclotron group, (10) Theoretical group, (11) Personnel listing.

"Equations for the heat-transfer coefficient existing at the interface of two metals in contact are discussed. The results of applying the equations (with a graphical determination of the geometric parameters) to an iron--aluminum contact are presented. A method is given for performing the graphical analysis by means of a general purpose analog computer. Data are included that were obtained by applying this method to Blanchard ground stainless steel surfaces in contact. Statistical analysis was applied to surfaces to determine the geometric properties of the contact as a function of root-mean-square roughness and method of surface preparation."