This progress report discusses the activities of the P Division for the month of January 1950. The B, D, F and H pilan operated throughout the month except for outages listed under Area Activities. Power levels were as follow: B pile -- 275 megawatts (MW) D pile -- 305 MW, F pile -- 275 MW increased to 305 MW during the month, and H pile -- 275 MW increased to 330 MW during the month. The piles operated with a time operated'' efficiency of 88.8%. A total of 53.07 tons of metal at an average of 91.2% of the current goal concentration was discharged from the piles during the month. A new record canning yield of 93.9% for 4 inch canned slugs was established during January.

Neutrons produced by 350 Mev protons impinging on beryllium are scattered by hydrogen. We measure the differential scattering cross section as a function of the scattering angle. Results are summarized in Fig. 3 of the paper.

Six subjects received a few millicuries Of tritium by inhalation of isotopically labeled hydrogen gas. The concentration of H{sup 3} in the urine of these individuals has been followed for a period of some 15 days. The rate of excretion of the tritium was found to be constant for a given subject but to vary considerably, among individuals. Data on five individuals arbitrarily normalized to coincide at zero time showed a range in biological half-life from about 9 days to nearly 13 days. These values are to be compared with the value calculated for the Chalk River ``Standard Man`` of 13.5 days, assuming the tritim to be confined to the body water.

This report discusses the following topics: (1) radium separation from K-65 residues - laboratory scale; (2) fractional crystallization studies barium - radium; (3) the concentration of radium from barium rich mixtures; (4) the coprecipitation of lead and radium sulfate; (5) the separation of radium and barium by ion-exchange; (6) engineering work on separation of radium from K-65 residues; (7) silica removal, corrosion tests; (8) radon counting; (9) the design of equipment for the measurements of radon in breath and air samples; and (10) proportional counting of radioactive gas.

The recent production and identification of isotopes of elements with atomic numbers up to six higher than the target element through bombardment with hexapositive 120-Mev carbon ions made it seem worthwhile to apply this technique to the transuranium region. Accordingly, small pieces of natural uranium metal (about 0.5 mil thick and 205 cm by 0.6 cm area) were irradiated in the internal carbon ion beam in the Berkeley 60-inch cyclotron. Following the irradiations, the uranium was dissolved in dilute hydrochloric acid containing hydrogen peroxide and a transplutonium fraction was isolated through the use of lanthanum fluoride, and lanthanum hydroxide precipitation steps followed by the ion exchange adsorption column procedure in which concentrated hydrochloric acid is used to separate the tripositive actinide elements from the rare earth elements. The transplutonium fractions in hydrochloric acid were evaporated as weightless films on platinum plates which were placed in the ionization chamber of the 48 channel pulse analyzer apparatus in order to measure the yield and energies of any alpha-particles which might be present. In the best experiment at about one hour after the end of the 90-minute bombardment, some 50 disintegrations per minute of the distinctive 7.1-Mev alpha-particles of Cf{sup 244} were observed …

The X-ray Spectrum Produced by 322 Mev Electrons Striking a Platinum Target. The differential energy spectrum of the photons produced by 322 Mev electrons striking a 20 mil platinum target was measured by observing the energy of 3467 pairs produced in a one mil thick lead foil in a Wilson cloud chamber in a magnetic field of 10,000 gauss. The spectrum is found to agree with that predicted by the Bethe-Heitler bremsstrahlung theory using a Thomas-Fermi model with suitable corrections for the thickness of the target. The energy of the 322 Mev electrons was determined by the spectrum of the photons observed in this experiment. Apparatus used and the experimental data and results obtained are reported fully in UCRL-660.

The efficient prosecution of the research and process development on polonium, radium, actinium, waste disposal, and alpha-neutron sources requires the use of a wide variety of instrumental techniques such as: alpha, beta, gamma, and neutron counters and survey meters; emission, absorption, and mass spectroscopy: x-ray and electron diffraction; microbalances; and calorimeters. The complex and kaleidoscopic aspects of our research program require; (1) The application of standard instruments and techniques to a variety of problems; (2) The development of new techniques for the use of standard instruments; and (3) The development of new or improved Instruments. The sum of the above three categories constitutes the field of supporting research. The amplifier for counting pulses of wide dynamic range which was developed for counting beta particles in the presence of alphas has operated so satisfactorily that it has been decided to attempt to adopt it for neutron counting. Substantial improvement at medium counting rates has already been obtained but results at high counting rates are not as satisfactory. The development of a survey meter for monitoring fast neutrons has been under way for sometime. The attainment of higher efficiency has been attempted by the use of a dual-chambered counter tube. The tube …

None

None

Mound Laboratory is cooperating on a joint development program directed toward the production of polonium-208 by proton irradiation of bismuth. Because of the greater half life of polonium-208 compared with polonium-210 (2.93 years versus 138.4 days), it would be a desirable substitute for polonium-210, At the present time the Electromagnetic Division of Oak Ridge National Laboratory is operating a cyclotron for the production of polonium-208 on an experimental scale. The targets produced are sent to Mound Laboratory for evaluation of the results which have been obtained, as well as for processing of the targets to obtain experimental amounts of the polonium in a purified form. The California Research Corporation is designing the target to be used in the Mark I linear accelerator located at Livermore, California. The overall responsibility for the Mark I design and operation is being handled by the California Research and Development Corporation. Before it is used for the production of polonium-208, the Mark I will be convert d from a deuteron beam, on which it will first operate, to a proton beam. This report describes progress on separation processes of bismuth and polonium, and diffusion of polonium through aluminium.

Activities discussed in this report are as follows: shielding studies; xenon generator; assay of xenon sample counting techniques; crystal diffraction neutron spectrometer; C{sup 12} cross sections measurements; magnetic spectrometer; scintillation spectroscopy; improved pile structure; criticality for the untamped 16 inch spherical reactor; exponential experiments; large scale pile structure; and operational pile physics.

None

A review of the present design information and studies relating to nuclear power plants indicates that the weight of the power plant components, exclusive of crew shield and nacelles, may at a particular design point be represented by an equation of the form, W{subpp} = W{subo} + K{subt}T. By use of this, a power plant parameter psi is defined as the ratio of the part of the power plant plus nacelle weight that varies with thrust to the net thrust of the power plant less nacelle drag. The funamentall part that this parameter plays in determining the gross weight of a nuclaer powered aircraft is shown. This parameter depends on the design point Mach number and altitude, and the weight and drag increments attributable to the nacelle installation.

None

Monthly activities for the following studies are given: (1) pile graphite monitoring; (2) graphite burnout and chemical studies; (3) graphite physical properties studies; (4) controlled temperature exposure; (5) thermal conductivity of gases; (6) damage mechanism study; (7) special exposures; and (8) experimental graphite program.

The purpose of this report is to specify the water flow rates and pressures which must be maintained at the process unit immediately following a Bonneville electrical power failure.

None

Experiments are described in which the change in thermal conductivity of U-impregnated graphite under neutron irradiation was measured. Thermal resistivities relative to the thermal resistivity of undamaged impregnated graphite are reorted as functions of exposure. From applications of the expermental results to the North American Aviation low-power research reactor the peak tem. of the core is determined for a given reactor power and time of operation.

This memorandum discusses procedures to test new methods of bonding boron to aluminum tubing in the fabrication of horizontal control rods.

The intercycle evaporators in the Chemical Processing Plant are controlled by density-measuring instruments. Because of difficulties in controlling these evaporators in a satisfactory manner, a series of investigations was begun to measure the boiling points at the elevation of the CPP, and densities near boiling temperatures of a number of solutions in the uranyl nitrate-nitric acid-water system. From these data it was hoped to evaluate temperature sensitve devices as controllers for the evaporators.

This report presents a brief review of reports concerning radiation hazards in the event of various reactor accidents. Conclusions regarding tolerance distance are reported.

The Bevatron status is: (1) Physical structure of magnet now assembled and being tested. Initial pulsing to rated field currents indicate that magnet is performing as designed. Currents of the order of 8500 amps peak have already been rendered. (About 15,000 gauss). (2) Pumpdown time to approximately 10{sup -5} mm Hg is of the order of 24 hours at present but is expected to improve to 12-15 hours as the high vapor pressure solvents are removed. Lofgren and Brobeck expect that it will be possible to make interval target, etc., changes between operating shifts without excessive loss of experimental time. (3) Injector and linear accelerator are now operating stably. Injected currents to Linac are approximately 3 x 10{sup -3} peak at 450 kev. Linac output is approximately 5% or 70 x 10{sup -6} amps peak with an angular divergence of 10{sup -3} rad. and a maximum energy spread of less than 0.8% at 9.8 kev. (4) Inflector and induction electrodes are to be installed after December 15, 1953. (5) Complete machine, both mechanical and electrical, will be ready for testing and 'de-bugging' approximately December 15; 1953. Initial operation as a research instrument should begin after the first of the year, …

On April 1, a new energy peak of 6.1 Bev was attained with the Bevatron. Scattered particles monitored with a counter telescope in triple coincidence gave approximately 100 counts per beam pulse. April 2s the machine was down to air to allow work on beam monitoring equipment. Test operations resumed April 5. Though the total number of accelerated particles is still small, due to low energy beam losses, some cloud chamber tracks have been observed. Several plates have been exposed for Goldhaber. Stars with up to 29 prongs have been observed. The following consists of a discussion of the administration, operation and some of the experimental techniques evolved in the use of the Cosmotron.

None