Since the 25 content of the uranium to be used in a MTA multiplying lattice is quite uncertain at present, it is necessary to assume various degrees of depletion in order to estimate the multiplication constant K-o and the production of 49 in an infinite uranium-graphite lattice

The attenuation curve of the deuterons stripped from He3 has been measured with a Faraday cup. The corresponding curve at 190 Mev was fit by assuming that the deuterons were monoenergetic, with three processes taking place.

In the past it was felt that the easiest way to treat a three group equation for a MTA lattice was to solve it without certain terms. This iterative procedure converged rapidly for a medium with depleted uranium fuel, and in fact, a second iteration was not needed.

The use of diffusion theory to attempt to reproduce the chemical data of Hicks and Stevenson for the spatial distribution of neutrons in a solid block of uranium that is bombarded by 190 Mev neutrons is described.

The energy distributions of neutrons in the 3-10 Mev energy range resulting from the bombardment of thin U targets are being investigated by the measurement of proton recoils in photographic plates.

At high excitation energies, competition of proton and c-particle emission with neutron emission becomes important. For low excitation, the competition between Y-emission, neutron emission, and fission should be taken into account. To aid in the evaluation of this competition an experiment has been performed to measure the number and energy spectrum of the protons and c-particles emitted in the high energy bombardment of uranium with protons, deuterons, and c-particles.

This paper is intended as a preliminary report on the Homopolar configuration (axial magnetic field with radial electric field), which is the rotating configuration most thoroughly studied thus far. The analysis presented in this paper applies principally to the "ideal" Homopolar, that is, the configuration free from electrode-sheath drops and other disturbing but remediable phenomena. Design considerations for various interesting plasma appliances are derived and documented with preliminary experimental results. The experiments have been carried out under high-density (pinch-type) conditions which favor the creation of a totally rotating plasma and the actual physical measurement of the characteristics of such a plasma. When larger models of the Homopolar are built, it will be possible to use the present pinch-type technique of plasma formation at much lower density, just as has been done in the case of the toroidal stabilized pinch.

The basic investigation of transistor feedback amplifiers has proven mathematically simple and of great practical value. The behavior of single-stage common-emitter amplifiers is described and provides a building block with which cascaded feedback amplifiers can be analyzed and designed. From the results of this analysis the conditions for minimum drift for cascaded single-stages and cascaded loops have been derived.

The writer has initiated a comprehensive program of equipment development designed to give the maximum practical aid to the physicists and technicians who are carrying out track measurements. Some attention has also been given to developing systems of data handling using International Business Machine (IBM) equipment and Keysort cards. In addition, some of the steps to insure the accuracy of the emulsion data are taken long before the emulsion is studied under the microscope.

Apparent [Sigma] hyperon decay events in a large emulsion stack of 240 9" x 12" pellicles have been classified into those judged to have occurred at rest and those in flight. Of 36 decay events at rest, 21 secondaries were observed to be protons of about 1675 microns range. Of the events decaying in flight, 23 were decays into protons and 46 were decays into near-minimum secondaries. Attempts have been made to trace the tracks of 35 of the lightly ionizing secondaries; the results of this effort are summarized in a table.

A set of 69 pile yield curves for the production of plutonium, americium, and curium isotopes in a neutron flux of 5 x 10<sup>14 cm<sup>-2 sec<sup>-1 is given. The differential analyzer of the University of California Radiation Laboratory was used in obtaining the curves. The curves are given also on log-log plots for comparison.

Bismuth metal was irradiated with 340 Mev protons in the circulating beam of the 184-inch Berkeley cyclotron. Nuclides formed as fission products during the course of the bombardment were separated and studied through the use of radiochemical techniques.

The excitation function for the reaction T3 (p, y) He4 has been extended to proton energies of 7.3 Mev. No experimental evidence is found for a resonance in the reaction up to this energy of bombarding protons.

An experiment was designed utilizing a charge-exchange reaction to study the decay and interactions of the neutral K mesons produced. The experiment produced no events that could be interpreted as either the decay or interaction of neutral K mesons. The nature of the experiment and the possible explanations of this unexpected result are presented in this paper.

In an effort to gain information on the nature of the photon-meson and photon-nucleon interaction, a study of the artificial production of mesons by photons has been made at the Berkeley synchrotron. The major effort of this research was concentrated on a measurement of the energy and angular distribution of u+-mesons produced when the photons strike a target of liquid hydrogen. Detection of the mesons is accomplished electronically by the technique of delayed coincidence.

Numerous articles have recently been published on nuclear pulse height analyses. This report describes an approach to the problem using existing scaling equipment (scale of 1024) as building blocks in a multi-channel pulse height analyzer.

Equations are derived for the rates of heating of objects in induction furnaces and for the maximum temperatures attainable. The equations are primarily useful in designing conducting crucibles, shells, and cylinders so as to increase the power input and decrease heat losses. A very brief treatment is given of the factors which influence the current in the induction coil. The performances of various induction furnaces are compared.

A systematic set of thermodynamic data for most of the known compounds of plutonium is presented. From earlier data present, it is now possible to extend the tabulation of data for the compounds of plutonium to include PuF(4), PuF(5), and PuF(6).

As there is no accurate measurements of the energy distribution of neutrons emerging from large uranium blocks, it becomes of importance to see how much information of this kind can be derived from the slowing down distribution of the neutrons in a water tank.

The use of thermally fissionable material in the lattice adds a distributed source of fast neutrons which must be considered in evaluating the problem.

The purpose of this note is to recalculate the semi-empirical curve of neutron yield vs. deuteron energy originally obtained by H. York in order to predict, using it and the best available data, what yields may be expected for deuterons on uranium in the extrapolated energy region.

The mathematics of the approximation is developed for the case of a H2O-cooled, graphite-moderated matrix

Calculations are developed which indicate the Pu production is an infinite lattice

A two-group approximation of the fission ratios and Pu production in an infinite hollow matrix is developed