This report discusses the multi-channel pulse analyser including its components and operation.

From cover page: This document has been assigned the above MDDC (Manhattan District Declassification) number, as given in the List of Declassified Documents issued semi-monthly by the Research Division, Manhattan District. In the case of Los Alapnos reports, LADC (Los Alamos Declassification) numbers are listed on the title page if known. This declassified document may differ materially from the original classified document by reason of deletions necessary to accomplish declassification. Hence, this copy of a declassified document does not constitute authority for declassification of classified copies of a similar document which may bear the same title and authors. Reference is made to District Circular Letter (Research Control 47-3) dated 31 October 1946, subject: "Instructions for Use of List of Declassified Documents," which outlines the procedure by means of which declassification of classified copies may be effected. Every effort has been made to reproduce with accuracy of detail the declassified document as certified for declassification. No corrections or changes have been made in the content of the document.

Abstract: Mice of different ages ranging from 1.5 to 12 months have been exposed to gamma rays in an effort to determine the change in radiosensitivity with age. The dose necessary to cause 50% killing was determined for each age group and sex. No change in sensitivity with age was observed with either sex, although the experimental error in the case of the males was quite large. The females were found to be more resistant than the males.

Abstract: The purpose of this research was to obtain data that would be useful in predicting changes that might be expected to occur in the oxidation state and degree of hydration of powdered uranium oxides maintained for long periods of time at temperatures between 30 and 300 degrees C. in the presence of excess water, hydrogen, oxygen and possibly hydrogen peroxide. The reaction of hydrogen and oxygen with water slurries of U3O8 were studied at 100-300 degree C.

Technical report describing a procedure for the determination of lead in pitchblende. The procedure was determined as needed in the course of an investigation of the processing of pitchblende for the production of uranium. Summary: The volumetric dichromate method for the determination of lead was selected from among several methods investigated as being best suited for a rapid determination of lead in pitchblende. The method as described is accurate to within 1% and it does not require the application of an empirical factor as suggested by Willard and Diehl for this determination.

Abstract: In the NaF-UF4 system the following intermediate phases have been found: NaUF5, -Na2UF6, -Na2UF6 and NacUF7. NaLaF4 is the only intermediate phase observed in the system NaF-LaF3. In the course of an incomplete study of the system NaF-ThF4 the phases NaTh2F9, -Na2ThF6, -Na2ThF6 and Na4ThF8 have been observed. Crystal structure data are given for all the phases.

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

This two page report discusses the processes followed and findings of an effort to estimate the minimum amount of hydrogen peroxide concentrations required for the formation of a precipitate in 50 percent solutions of uranyl nitrate and uranyl sulfate containing various concentrations of excess anion as acid. The report contains a table detailing the results.

From introduction: "The first part deals with stationary detonation waves...the second part is concerned with the structure of detonation waves of finite age...the third part deals with the steady state motion attained by a detonation wave in certain cases of two-dimensional flow."

From abstract: "Some investigations have been made to ascertain the similarity of the mechanism of action of radiation which are different in their specific ionization. A suggested approach was to determine if the energies absorbed from the different types of radiation are additive in their lethal effects on biological objects. In an attempt to determine the additivity of ionizing radiation various dose combinations of fast neutrons, gamma rays and beta rays were administered to Drosophila eggs. These test objects were chosen because their dimensions are such that they tend to absorb these three radiations uniformly throughout their volume. Although the three radiations were found to vary in their biological effectiveness, per unit energy absorbed, all three were shown to be completely additive in their lethal effect on these organisms."

From abstract: "In estimating the activities of β-emitting materials used in the Biology Section, most measurements were made with Geiger-Mueller counters, although Lauritsen electroscopes were used in early work. All samples were mounted on flat porcelain capsules."

From abstract: "This report describes methods used for radiochemical analysis of fission products most used in the Experimental Biology Section. The report includes methods of analysis of Sr89, Ba140-La140, Zr95-Cb95, Ce144-Pr144, and Y91 by standard chemical procedures. In addition, a method of analysis by use of an absorption curve is described in some detail for Zr95-Cb95 mixtures. The absorption curve method makes possible rapid determination of percentage composition of a mixture of isotopes with a minimum of chemical manipulation by utilizing the differences in absorption characteristics of the emitted rays."

From introduction: "These data were taken on a 1/16th scale model of the magnet shown on sketch no. FS-2. The object of these measurements was to get information that would determine the final design of the full scale magnet. The one main point to be settled was whether a tapered or a cylindrical pole piece would give the largest value of Hρ for a given power input into the magnet (the cylindrical pole piece is shown in dotted lines in sketch FS-2)."

From abstract: "This is a review, with annotated bibliography, of the mode of occurrence of the elements columbium and tantalum. It is not a list of specific ore deposits, but a summary of the types of minerals and rocks in which these elements have been reported to occur. In addition, the unpublished spectrographic studies of the Geological Survey are summarized, best sources for columbium and tantalum are indicated, and suggestions are made for further investigation."

From abstract: "This is a review, with annotated bibliography, of the mode of occurrence of the element germanium. It is not a list of specific ore deposits, but a summary of the types of minerals and rocks in which germanium has been reported to occur. Best sources for germanium are indicated, based on the data in the literature and on the unpublished spectrographic studies of the Geological Survey on mill and smelter products. Suggestions are made for further investigations."

From abstract: "The distribution of carrier-free thorium, protoactinium and neptunium in the rat following intramuscular and oral administration has been studied. Oral adsorption for all three is negligible. Following parenteral administration, the skeleton is the organ showing the highest degree of prolonged and selective localization."

From introduction: "Due to the hydrogen overvoltage at the surface of a mercury cathode, uranium solutions is hydrochloric acid may be reduced not only to the tetravalent state, but until considerable trivalent uranium is formed. Other metallic ions act as oxidation-reduction catalysts as well as being reduced themselves. The following paper is a study of the various reactions taking place in solution and at the surface of the cathode."

From abstract: "Benzene shows weak absorption bands in the 3 aliphatic C-Z region of the spectrum. The peaks of these bands are at 3.439, 3.459, 3.504, and 3.545."

From abstract: "Several different techniques were used to introduce tracer quantities of plutonium into the lungs of rats. When aerosols were produced by atomizing aqueous solutions of the nitrates it was found that approximately 20 per cent of the dose was absorbed and deposited in the skelton [sic] with tetra-, hexa-, and trivalent plutonium. Thus with these compounds, the lungs represent a more dangerous portal of entry than either oral (0.05 per cent) or intramuscular (13 per cent) administration. Tetravalent Pu was eliminated most slowly from the lung, the average half-time during the first month being 15 days. But when citrate was added to complex the Pu, over 70 per cent was eliminated within 1 day. This was accompanied by a deposition of over 30 per cent in the skelton [sic] and over 20 per cent in the liver. Presumably citrate breaks up the insoluble colloid in which Pu exists in the lungs. Complexing with cupferron which, unlike citrate, produces a "fat soluble" compound, greatly diminished the extent of absorption from the lungs. Plutonium oxide smokes which were produced at high temperatures were eliminated more slowly from the lungs (average half time of 30 days during the first month) and …

From introductory paragraph: "This is the first quarterly report of the Biology Division of the Argonne National Laboratory. During the three-month period covered by this report, a large share of the time of many investigators has been spent in collating work done under the Biology Section of the Metallurgical laboratory for publication in the Plutonium Project Record. The large amount of work done under wartime pressure has made this, as in other divisions and projects, an important part of the transition to the post-war period."

This technical report is divided into two sections addressing two different chemical effects of nuclear transformations. The first section discusses the beta decay of lanthanum to cerium. The second section discusses the beta decay of selenium to bromine.

From abstract: "In an attempt to gain some insight into the physiological condition of mice surviving massive doses of radiation, a study of their vitality was undertaken. It was assured that the ability of these animals to do forced work would be a measure of their vitality, Stimulating exposed animals to run in exercise wheels to their fullest capacity, has resulted in a demonstration of a striking vitality less during a post-irradiative period, when no other effects are demonstrable by gross examination. Mice subjected to a medium-lethal dose of fast neutrons show a continuous vitality loss over a 300 day period following exposure. Control animals show no appreciable loss of vitality up to about 8 months of age, after which a gradual loss can be noted, probably due to a normal gereologic process."

Abstract: This is basically a counting rate meter, with an alarm circuit, operating from four GM tubes as the detecting elements. The Hand Counter comprises four logarithmic counting rate meters working from four GM tubes mounted individually, with associated electronic circuits, in suitable shields with a metal mesh type of window. Both sides of both hands are sampled simultaneously. In the Foot Counter, two GM tubes are separately and mounted in a suitable mesh window shielded with the electronic circuit; the foot counter uses only two counting rate meters, and both feet are sampled simultaneously. Each circuit is built in two parts; two tubes are in the shield and the balance of the circuit is in the electronic unit which is a standard 17" x 13" chassis. Circuit diagrams are included.

Technical report discussion of the complicated problem of the spatial distribution of slowed down neutrons. The introduction covers the current research on the topic. The following chapters cover the topics: (1) approximate treatment and its limitations, (2) age-velocity distribution, (3) general scheme of treatment based on transport equation, (4) Fermi's one-dimensional model, (5) moments, (6) remarks about the distribution function, and (7) point source.