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  Partner: UNT Libraries Government Documents Department
 Decade: 1940-1949
Biological Effects of Radiation

Biological Effects of Radiation

Date: August 10, 1948
Creator: Evans, R. D.
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Biological Effects of Radiation on Man: Discussion with Col. Cooney

Biological Effects of Radiation on Man: Discussion with Col. Cooney

Date: September 15, 1948
Creator: Friedman, F. L.
Description: None
Contributing Partner: UNT Libraries Government Documents Department
The Fission of Thorium with Alpha Particles

The Fission of Thorium with Alpha Particles

Date: April 15, 1948
Creator: Newton, Amos S.
Description: The fission distribution of fission of thorium with alpha particle of average energy 37.5 Mev has been measured by the chemical method. The distribution found shows that the characteristic dip in the fission yield mass spectrum has been raised to within a factor of two of the peaks compared to a factor of 600 in slow neutron fission of U{sup 235}. The raise in the deip has caused a corresponding lowering in fission yield of these elements at the peaks. The cross section for fission of thorium with 37.5 Mev alphas was found to be about 0.6 barn, and the threshold for fission was found to be 23 to 24 Mev.
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The Fission of thorium with Alpha Particles

The Fission of thorium with Alpha Particles

Date: October 15, 1948
Creator: Newton, Amos S.
Description: Soon after the discovery of fission, Meitner, Bretscher and Cook found differences in the decay of various chemical fractions separated from uranium irradiated with slow neutrons and thorium irradiated with fast neutrons respectively and suggested that a difference existed in the distribution of fission products in the two cases. In 1940, Turner suggested that the distribution in various modes of fission should be investigated. The fact that elements such as tin, cadmium, palladium, and silver were found in fast neutron and deuteron fission of uranium and thorium before they were found in slow neutron fission of uranium suggested that the middle region of the distribution was raised as the energy of the incident particle was increased. Since the compound nucleus formed in the fission of thorium with alpha particles is U{sup 236}, the same compound nucleus formed in the fission of U{sup 235} with neutrons, it is of interest to study the fission of thorium with alphas and compare the resulting distribution of fission products with that found with uranium with slow and thorium with fast neutrons. Any difference between the various results where the same compound nucleus is formed must be due to differences in energy content and possible ...
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The Distribution of Radioactivity in the Mouse Following Administration of Dibenzanthracene Labeled in the 9 and 10 Positions with Carbon Fourteen

The Distribution of Radioactivity in the Mouse Following Administration of Dibenzanthracene Labeled in the 9 and 10 Positions with Carbon Fourteen

Date: January 30, 1948
Creator: Heidelberger, Charles & Jones, Hardin, B.
Description: Dibenzanthracene, labeled in the 9 and 10 positions with carbon fourteen has been administered to mice intravenously and by stomach tube as an aqueous colloid, and intraperitoneally, subcutaneously, and by stomach tube in tricaprylin solution. The distribution of radioactivity in the mice at various time intervals after administration of the carcinogen has been determined. The radioactivity is rapidly eliminated, largely through the feces, and ordinarily very little is absorbed. The distribution and rate of elimination depends upon the mode of administration. There is an appreciable quantity of radioactivity in tumors produced several months after a single subcutaneous injection of dibenzanthracene. There appear to be no detectable effects from the radiation of the labeled carcinogen.
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Diffraction Effects in Neutron Attenuation Measurements

Diffraction Effects in Neutron Attenuation Measurements

Date: November 1, 1947
Creator: Sewell, D.C. & McMillan, E.M.
Description: All errors due to diffraction effects in a neutron attenuation experiment are computed. Also a special experiment to measure the forward intensity of diffracted neutrons from lead and copper is described, and the results given. These agree with the theoretical values.
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Progress Report for October 1947, Physics Section

Progress Report for October 1947, Physics Section

Date: October 1, 1947
Creator: Brobeck, W.M.; Hamilton, J.G.; Martin, M.; Alvarez, L.W.; Thornton, R.L.; Serber, R. et al.
Description: This summary discusses the following topics: (1) 184-inch cyclotron program; (2) a 60-inch cyclotron program; (3) synchrotron program; (4) Linear accelerator program; (5) Experimental physics, experiments with the 184-inch cyclotron, fast neutron scattering, and neutron-proton scattering; (6) Theoretical physics; and (7) isotope research program.
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Proton Angular Distribution for 90 Mev Neutron-proton Scattering

Proton Angular Distribution for 90 Mev Neutron-proton Scattering

Date: November 3, 1947
Creator: Hadley, James; Leith, Cecil E. & York, Herbert F.
Description: The angular distribution of the recoil protons in neutron-proton scattering at 90 Mev has been measured for angles between 5{sup o} and 65{sup o} from the direction of the neutron beam. The neutrons were produced by stripping 190 Mev deuterons in a 1/2 inch Be target in the 184-inch F.M. cyclotron. R. Serber has calculated the neutron energy distribution; it has a peak at 90 Mev and a half width of 27 Mev. This distributiQn has been checked experimentally for the neutrons by Wilson Powell and by W.Chupp, E.Gardner, and T.B.Taylor for the protons also produced by stripping. The neutrons were collimated by a two-inch hole through 8 feet of concrete. Thin paraffin scatters of known hydrogen and carbon content were used; the number of protons arising from neutron-carbon and neutron-air reactions was determined by using pure carbon scatters and by making blank runs. The scatters were placed in the beam outside of the concrete shielding at a point approximately 52 feet from the cyclotron target. The scattered protons were detected by a telescope of four proportional counters used in coincidence, and set at a constant distance from the scatterer but at a varying angle from the neutron beam. A ...
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Proton Angular Distribution for 90 Mev Neutron-proton Scattering

Proton Angular Distribution for 90 Mev Neutron-proton Scattering

Date: November 3, 1947
Creator: Hadley, James; Leith, Cecil E. & York, Herbert F.
Description: None
Contributing Partner: UNT Libraries Government Documents Department
Production of Mesons by the 184-inch Berkeley Cyclotron

Production of Mesons by the 184-inch Berkeley Cyclotron

Date: January 1, 1948
Creator: Gardner, Eugene & Lattes, C.M.G.
Description: The authors have observed tracks which they believe to be due to mesons in photographic plates placed near a target bombarded by 380 Mev alpha particles. For a 10-minute exposure in the cyclotron, about 50 meson tracks are found along the 3-inch edge of a photographic plate. The mass has been determined by measuring the bending in the magnetic field and the range in emulsion. From the first 50 meson tracks measured they find a mass of 313 {+-} 16 electron masses. It is highly probable that these mesons are the heavy mesons described by Lattes, Occhialini, and Powell.
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Production of Mesons by the 184-inch Berkeley Cyclotron Part I. Experimental Arrangement

Production of Mesons by the 184-inch Berkeley Cyclotron Part I. Experimental Arrangement

Date: April 1, 1948
Creator: Gardner, Eugene & Lattes, C.M.G.
Description: The authors have observed traks which they believe to be due to mesons in photographic plates placed near a ta5rget bombarded by 380 Mev alpha particles. The plates used were Ilford Nuclear Research Plates, type C.2. the identification of the particles responsible for the tracks was first made on the basis of the appearance of the tracks; they show the same type of scattering and variation of grain density with residual range found in cosmic ray meson tracks and about two-thirds of them produce observable stars at the end of their range. For a 10-minute exposure in the cyclotron, about 50 meson tracks are found along the 3-inch edge of a photographic plate. Carbon, beryllium, copper, and uranium have been used so far as target materials, and all are found to give mesons. When a carbon target was bombarded with 300 Mev alpha particles, mesons were found but with reduced yield.
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The Production of Thin Be Foils

The Production of Thin Be Foils

Date: March 18, 1948
Creator: Bradner, Hugh
Description: 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.
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Products of High-Energy Deuteron and Helium Ion Bombardments of Copper

Products of High-Energy Deuteron and Helium Ion Bombardments of Copper

Date: March 1, 1948
Creator: Miller, D.R.; Thompson, R.C. & Cunningham, B.B.
Description: 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.
Contributing Partner: UNT Libraries Government Documents Department
Progress Report for 1947

Progress Report for 1947

Date: November 1, 1947
Creator: Authors, Various
Description: The year 1947 has witnessed the dawn of a new era of atomic science, a flowering of fundamental knowledge of the nature of matter which appears to be unsurpassed even by that period of the 1930's which led to the age of plutonium. A great new cyclotron, an atom-smasher ten times more powerful than the one which brought plutonium into the world, has carried mankind over a new horizon of sub-atomic space. It has brought scientists at last to grips with the infinitely small and rapid forces, until now beyond reach, which operate within the incredibly tiny distances of nuclear space. On the new energy frontier created by the giant machine, now laws govern nuclear reactions. methods are at hand, heretofore unavailable, which permit the measurement and determination of the nature of sub-atomic forces. Under ultra-high energy bombardment, the nucleus presents a different appearance from the nucleus of Bohr and Rutherford, the nucleus of atomic energy fission. The new exploration of the atom has been sponsored by the Atomic Energy Commission with the giant, new 4000-ton cyclotron in the Radiation Laboratory of the University of California. This is the thirdmajor machine built by the Director of the Laboratory and inventor ...
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Summary of the Reseach Progress Meeting

Summary of the Reseach Progress Meeting

Date: November 1, 1947
Creator: O'Brien, Inez
Description: A 1,000 Mev synchrotron is under construction. The magnet will be a ring magnet containing about 900 tons of steel. The plates are of 1.2 inch steel with a 0.1 percent carbon content. A diagram of the cross section of this magnet is given in Figure 1. The design of the vacuum chmnber presents some difficulties since the space behind the gap is not large enough to permit easy access to the windings and to the vacuum space behind the gap. The field strength at the gap is 15,000 gauss with a 1 sec. rise time. A d.c. generator of 1,000 v and 10,000 amps and a flywheel will be used to energize the magnet and store the energy. Plans for the vacuum system are not complete, but probably a porcelain system will be used. This will reduce the gap quite considerably. It is planned to inject at 3,000 volts. The energy added to be about 200 ev per revolution. The frequency range is 250 kc/sec to 10 mc/sec; the power required is 10 Kw. A diagrammatic view of the electrical arrangement of the r.f. system is given.The variable inductance is a coil tipped at variable pitch into a pool ...
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Summary of the Research Progress Meeting

Summary of the Research Progress Meeting

Date: March 18, 1948
Creator: Folden, M.F.
Description: 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.
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Summary of the Research Progress Meeting

Summary of the Research Progress Meeting

Date: November 1, 1947
Creator: Wakerling, R.K.
Description: This summary discusses the following topics: (1) Neutron Scattering. By R. Hildebrand. A series of measurements have been made of the angular distribution of neutrons scattered from small spheres of various materials placed in the neutron beam of the l84-inch cyclotron. The scattered neutrons were detected by copper covered carbon detectors placed in a symmetrical arrangement about the scatterer. The carbon detectors, which wore activated by the neutrons through the C{sup 12}(n, 2n)C{sup 11} reaction, were counted using an arrangement involving four counting tubes. The copper around the detectors served the purpose of stopping any protons. A carbon disk monitor was placed at the collimating channel in the cyclotron shield. This disk Was also counted by the same arrangement. (2) Electrical Resistance of the Blood. By R. Rosenthal. It has been found that animals exposed to total body irradiation developed in their blood an anti-coagulant called heparin. This substance, which can be produced synthetically, has the property of prolonging the clotting time of the blood. In an article which appeared in 'Science' some work was reported on the variation of the electrical resistance of the blood with the amount of heparin present, If some simple relationship could be found between ...
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Summary of the Research Progress Meeting

Summary of the Research Progress Meeting

Date: April 8, 1948
Creator: Wakerling, R.K.
Description: This report discusses progress on the following topics: (1) some new isotopes in the rare earth region; (2) remarks on a new alpha series; (3) solid counters; (4) naphthalene crystals have been replaced with anthracite in one of the experimental counters and some excellent results are obtained; and (5) biological experiments with the deuteron bean of the 184-inch cyclotron.
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Studies with Colloids Containing Radioisotopes of Yttrium, Zirconium, Columbium, and Lanthanum: 1. The Chemical Principles and Methods Involved in Preparation of Colloids of Yttrium, Zirconium, Columbium, and Lanthanum

Studies with Colloids Containing Radioisotopes of Yttrium, Zirconium, Columbium, and Lanthanum: 1. The Chemical Principles and Methods Involved in Preparation of Colloids of Yttrium, Zirconium, Columbium, and Lanthanum

Date: April 21, 1948
Creator: Gofman, John W.
Description: For a number of investigations, including fundamental studies of radiation effects on living tissues and therapeutic utilization of radioisotopes, it is valuable to have methods for the selective localization of radioisotopes in certain tissues. Finely dispersed anhydrous chromic phosphate has been found useful by Jones, Wrobel, and Lyons in selectively irradiating the liver and spleen with p{sup 32} beta particles. The present studies, reported in this and the following communication, are concerned with methods for controlled selective localization of colloids (incorporating radioisotopes) in the liver, spleen, or bone marrow, and with an analysis of some of the factors involved in the phenomenon of localization.
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Studies with Colloids Containing Radioisotopes of Yttrium, Zirconium, Columbium and Lanthaum: 2. The Controlled Selective Localization of Radioisotopes of Yttrium, Zirconium, Columbium in the Bone Marrow, Liver and Spleen

Studies with Colloids Containing Radioisotopes of Yttrium, Zirconium, Columbium and Lanthaum: 2. The Controlled Selective Localization of Radioisotopes of Yttrium, Zirconium, Columbium in the Bone Marrow, Liver and Spleen

Date: April 21, 1948
Creator: Dobson, E.L.; Gofman, J.W.; Jones, H.B.; Kelly, Lola S. & Walker, L.
Description: Several workers have shown that certain colloidally dispered materials are removed from the blood stream by the liver and spleen. Jones, Wrobel, and Lyons have utilized suspensions of anhydrous chromic phosphate for the selective irradiation of the liver and spleen with p{sup 32} beta particles. Gersh demonstrated that colloidal calcium phosphate is taken up by the liver and spleen. He stressed the failure of bone marrow phagocytes to take up this colloid in rats and dogs (though he referred to possible uptake in the marrow of rabbits under special conditions), and commented on the relative 'refractoriness' in general of the bono marrow as compared with liver and spleen with respect to the uptake of colloidal dyes from the blood stream. Some histological data indicate that 'Thorotrast' (a colloidal thorium dioxide preparation) is deposited in the bone marrow as well as in the liver and spleen, but no quantitative data as to the relative distribution are available. In the preceding communication the methods for the preparation of colloids incorporating radioisotopes of yttrium, columbium, and zirconium were given. The present studies are concerned with the localization of such colloids primarily in the bone marrow or primarily in the spleen and liver, with ...
Contributing Partner: UNT Libraries Government Documents Department
The Metabolism of Curium in the RAT

The Metabolism of Curium in the RAT

Date: January 15, 1948
Creator: Hamilton, J.; Scott, K. & Axelrod, D.
Description: The heaviest of the known elements is curium, which was recently discovered by Seaborg and his associates. This new element can be produced by the alpha particle transmutation of plutonium by the following reaction: {sub 94}Pu{sup 239} + {sub 2}He{sup 4} {yields} {sub 96}Cm{sup 242} + {sub 0}N{sup 1} This isotope of curium is radioactive and decays by the emission of an alpha particle to form plutonium 238 which, in turn, is also radioactive. Curium 242 has a half-life of 150 days, and its radioactive daughter, plutonium 238, has a half-life of 50 years. This isotope of plutonium decays by the emission of an alpha particle to form uranium 234 which has a half-life of 233,000 years. Shortly after the organization of the Atomic Energy Project, it became apparent that formidable problems would be presented as the result of the release of nuclear energy. One of the most urgent of these was the hazard presented by the production of large quantities of the radio-elements created by the fission of uranium and the coincidental formation of neptunium and plutonium. In an attempt to evaluate the potential danger presented by these radio-elements from the chain reacting pile, a large series of metabolic ...
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Medical and Health Divisions Quarterly Report October 1947 To Jan. 1948

Medical and Health Divisions Quarterly Report October 1947 To Jan. 1948

Date: February 4, 1948
Creator: Authors, Various
Description: This quarterly report discusses the following topics: (1) the metabolic properties of plutonium and allied materials; (2) biological studies of radiation effects; (3) biological effects of radiation from external and internal zones; and (4) health chemistry.
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The Metabolic Properties of the Fission Products and Actinide Elements

The Metabolic Properties of the Fission Products and Actinide Elements

Date: March 1, 1948
Creator: Hamilton M.D., J.G.
Description: 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.
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Estimation of Required Shield Thickness

Estimation of Required Shield Thickness

Date: September 16, 1948
Creator: Goertzel, Gerald
Description: None
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