The present report is concerned with the electronic relay which, upon the reaching of a pre-determined value of ionization current in the associated chamber, actuates the safety rod release mechanism. The are here proposed two independent suggestions: (1) An improved trip circuit of such sensitivity and stability as to allow it to be actuated by a signal directly from the chamber without the necessity of interposing intermediate amplifier stages. The value of chamber current at which tripping occurs is stable to +- 0.4%. (2) A triple-wound relay to prevent shut-downs of the pile which would otherwise be caused by development of defects in the safety circuits.

Technical report with short reports from the (1) Experimental Nuclear Physics Group; (2) Theoretical Physics Group ; (3) Lattice Design Group; (4) Pile Design Group; (5) Exponential Experimental Group; (6) Radiation Group; and (7) Shielding Group.

The following report on the nuclear synthesis of technetium is based on work performed under contract No. W-7405-eng-26 for the Atomic Energy Project at Oak Ridge National Laboratory.

The following report discusses the renewed element 43, or eka-manganese, whose discovery was heralded in 1925, but whose chemical properties remained unreported until the radiochemical investigations of Perrier and Segre."

Abstract: "A method of recovering the tuballoy from the trap washes of the high temperature salvage chlorinator is described."

From abstract: "A simple electronic circuit is described, the use of which greatly improves the temperature regulations obtainable with Beta equipment. The circuit utilizes the time derivative of the temperature to counteract oscillation and overshoot. No other changes are required in existing equipment for installation of the stabilizer."

Abstract: Twenty-two metallic oxides were refluxed with hexachloropropylene. The anhydrous chlorides or other products formed are described for each oxide. The reactions were particularly vigorous with higher valent oxides of the fifth and sixth group elements.

From abstract: "This report contains a summary of biological information on distribution, excretion, and toxicity of polonium; a comparison of results obtained when maximum permissible exposure rates for man are calculated from available data by different methods; and a critical evaluation of the present status of Po tolerance estimates."

The following report provides data based off of the solubility of sodium uranyl acetate that was measured under a variety if conditions.

The thermal decomposition of the higher oxides of praseodymium and americium have been investigated.

This report describes observations of a sample of Carbon-14, or radiocarbon, made using the method of mass spectrometry.

This report discusses the field of nucleonics in the wake of the development of the atomic bomb, ruminating on the training and curriculum necessary for the next generation of chemical and nuclear engineers.

From abstract: "A pile will run steadily at an arbitrary level if it is just critical. For a pile not at equilibrium, equations of motion can be set up that contain as variables the pile power, the number of delayed neutron emitters and, in case it is of importance, also the pile temperature. The coefficients will depend on the average lifetime of the neutrons in the pile, the fractions and periods of delayed neutrons, temperature coefficients of resistivity and similar quantities. For a definite 'excess resistivity', which may be positive or negative, the power level will change exponentially with time with periods determined by the so-called 'labour' relation. For control and safety problems the transient behavior of the pile under reactivity changes has to be investigated. A number of limiting cases can be solved explicitly. A general method for the solution of the pile equations is available for small deviations from a steady state. In this case a pile impedance can be defined in close analogy to electric circuit theory."

Positive and negative mesons produced in a common target in the cyclotron are received in two photographic plates. In the magnetic field of the cyclotron, negatives are deflected to one plate, positives to the other. The mesons must pass through an absorber before entering the plates in order to be observable.

Technical report with short reports on (1) Effect of radiation on organic compounds; (2) Effect of radiation on separation processes; (3) Effect of radiation on water and aqueous systems; and (4) Effect of neutrons on graphite.

Calculations were made to determine the temperature at various points of a thick disc and cap, on the assumptions that the heat production rate is uniform throughout the slug and that the slug is in perfect thermal contact with the cap. Results obtained by different methods of computation are compared with each other and with results obtained by Drew on the Paschkis electrical network computer at Columbia University.

Abstract. Some idealized calculations (CP-807) relating to the design of heat exchangers for minimum holdup of pile liquid are presented in compact form to facilitate quick estimates. Their use is illustrated by application to a falling film type exchanger.

With discussion under way concerning power production by chain reacting piles, it becomes pertinent to consider the ration of the temperature of the hottest spot in the pile to the average exit temperature of the cooling stream. This is important because the temperature of the hottest spot in the pile is one of the limiting factors in determining the maximum power at which a pile can be operated. However, the higher the temperature of the emerging cooling stream, the more efficient can be the thermal engine operated by it. Thus the ideal situation is to have the average exit temperature of the cooling stream as near as possible to the hottest temperature of the hottest spot in the pile.

Technical report with short reports on (1) P-9 recovery from UO2F2 solution; (2) Correlation of theories on action of radiation on matter; (3) Literature surveys on organic compounds and on chemistry of UO2F2; (4) effect of radiation on organic compounds; and (5) Effect of radiation on 100 area construction materials.

The problem of the separation or enrichment of isotopes is as old as the knowledge of the existence of isotopes of stable elements. The article focuses on the mass-dependent property of atoms continuing to be investigated in laboratories to test its usefulness for new solutions to this problem.