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

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.

Five isotopes of bismuth occur in nature. Using particle accelerators providing helium ions up to 40 Mev in energy and deuterons up to 20 Mev in energy, it was possible to produce and identify two artificial radioactive isotopes. With the advent of the 184-inch Berkeley syncho-cyclotron and its hundreds of Mev energies, it was possible to form highly neutron-deficient bismuth isotopes extending more than ten mass units below stable Bi(209).

The general method of controlling the radio frequency for the full scale Bevatron will be the same as that used on the 1/4 scale machine. The details of course will be modified to meet the requirements of greater range, higher output voltage and closer tracking tolerances. In addition, there is the added complication introduced by the current ripple.

Calculations presented were done to determine what maximum temperature gradients and stresses would be in typical designs of flat thorium plates, 100 mils thick and coolled on both sides by NaK.

Calculations indicative of the power loss for 75 in.radius gap splitters are given.

Studies of ionic entropies in methanol and ammonia have led to the suggestion that ionic entropies in water are abnormally high. An explanation of this hypothesis may be given in terms of entropies of solvation and the high degree of hydrogen bonding in water. When an ion enters water, more disorder is created than when it enters another, less hydrogen-bonded, solvent.

The question has arisen of how the beam in A-12 as a long resonant cavity might effect the frequency of operation and the field distribution. This study is published to make available the calculation of the direct beam effect as an illustration of general methods of attacking perturbing effects in resonant cavities.

Summary of progress on various research projects conducted during January, 1952.

Radioactive decay data are used to calculate the atomic masses of the heavy isotopes, A> 203. The four radioactive families are then connected by means of neutron binding energies known from reactions on various isotopes. Finally all the masses are collectively adjusted for the best fit with mass spectrographic information available in this region. The masses so calculated are presented. Differences between masses of isotopes are estimated to have an of (plus/minus) 0.00020 mas units or about 200 Kev; the position of the masses taken collectively is in doubt by about 1.5 Mev.

The study was undertaken with the objective of observing the distribution in the rat of organic compounds of phosphorus labelled with the P32 isotope as tracer. The fate of several of these compounds was studied in animals bearing tumors. The distribution of inorganic phosphate in animal tissues is well known but was included in this work for comparison with the organic phosphorus compounds.

The angular distribution of the reaction p + p--w+ + d has been measured with the meson and deuteron detected in coincidence. Measurements were made at 30' and 90' in the center of mass system for an incident proton energy of 338 Mev. Similar measurements were made at 30', 60' and 90' for 332 Mev protons.

The purpose of this letter is to point out certain discrepancies between previous work on the decay of Rb82 (6.3 hour, B+, K-capture) and studies made recently at the University of California Radiation Laboratory.

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.

In the past year, exploratory data have been taken to determine the relative solubilities of hydrogen and deuterium in various solvents in the vicinity of room temperature and atmospheric pressure. This investigation is one phase of a program to determine the feasibility of separating deuterium from hydrogen by means of rectified absorption.

Absolute differential cross sections for the reaction p + p - w+ + d were obtained by detecting meson-deuteron coincidences produced by passing the 340-Mev external proton beam of the Berkeley synchro-cyclotron through a liquid hydrogen target.

The angular distribution of charged x mesons produced by 300 <x> 30 Mev neutrons on C12 and Be9 have been studied. An analysis of the kinematics for meson production in a nucleon-nucleon collision indicates a fairly well defined center-of-mass system.

Progress reports on Accelerator Development Program, High Frequency Program, beam dynamics in strong focusing linear accelerators, spiral beam buncher experiments, dynamical properties of Mark I, mechanical design, and Target Physics Program.

An apparatus is described that permits the use of highly ionizing radiations of the Berkeley 60-inch Cyclotron for radiobiological experimentation (ie., deuterons, alpha particles and carbon nuclei).

With the increasing availability of accelerators capable of producing beams of heavy ions it has become useful to know the cross section for a heavy ion to form a compound nucleus by interaction with a target nucleus. The results of calculations based on two simple models are presented here in order to give some idea of the magnitude of this cross section as a function of the energy of the bombarding particle.

Since 1940 ten transuranium elements have been discovered. This lecture describes the history of these elements and the methods used in their discovery.

A method is presented for measuring the average energy of the neutrons from a source. The attenuation of the neutrons by polyethylene is measured by the use of a long counter in good geometry. The attenuation length is a sensitive function of the neutron energy. The average neutron energies from several (o, n) sources have been measured and agree well with values obtained by other techniques.

This report was prepared at the request of the Subcommittee on Radiochemistry of the Committee on Nuclear Science of the National Research Council as a contribution to a proposed master file on the radiochemistry of all the elements. All known material on the radiochemistry of thorium is included in this report.

Thin foils suitable for transmission electron microscopy have been prepared from bulk specimens of Cu-12.0% Al alloy quenched from 800' C to produce martensite. The martensitic structure consists of long lenticular plates which are twinned on 20-50A scale. The twin planes in the martensite are shown to be [formula]. There is evidence that this structure is ordered as expected for a transformation from an ordered parent lattice. Experiments using a high temperature stage show that the decomposition of the martensite on tempering can be followed directly, but the martensitic transformation did not recur on cooling.