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.

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.

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

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 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.

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

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).

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.

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.

Recent underground nuclear tests conducted by the U.S. Atomic Energy Commission have yielded data on the effects of contained nuclear explosions in four rock mediums: tuff, alluvium, rock salt, and granite. This report presents and compares data obtained primarily through exploratory mining and drilling into the postshot environment of 35 such events.

In this study, a physical-numerical model is used to investigate processes important for cratering, or excavation, physics for high-explosive sources in desert alluvium. High explosives do not vaporize much of the geological environment surrounding the initial cavity containing the explosive. Thus, a relatively simple, and in some cases a well-known, equation of state exists for the high-explosive cavity gas for pressure greater than 1 atmosphere. However, nuclear explosives are known to vaporize a great deal of surrounding geological environment during the early part of cavity life history. This vaporized material is believed to condense late in the life history of the cavity, and prior to vent of the cavity gas to the atmosphere, such that the latent heat of condensation plays an important role in nuclear excavation. So far, no numerical-physical models of the response of a geologic environment to a nuclear explosive includes the effect of condensation on the hydrodynamics of late times. Thus, the calculation of the cavity pressure at late times including the effect of condensation is one of the current unsolved problems in the calculation of a crater formed by nuclear explosives. This study, then, develops a predictive, numerical-physical model for H.E. sources of the cavity …

The production of energy by nuclear reactions results in the production of radioactive nuclei. Therefore, in considering the possible utilization of nuclear explosives for peaceful purposes it is necessary to be able to predict the expected activities, their amounts, and dispositions. The amounts and kinds of radioactivities produced by detonation of a nuclear explosive are dependent upon the specific design of the explosive. The behavior and ultimate fate of the activities produced by the explosion depend on the composition of the medium in which the detonation occurs, the nature of the detonation, and the chemical species involved.

In any underground nuclear explosion, the shock front that propagates from the shot point carries with it energy from the explosion, and distributes this energy by doing work on the surrounding material. In the process, the material undergoes changes in both its physical and mechanical states. If enough energy is deposited in the material, it will vaporize or melt thus changing its physical state, or cause it to crush or crack. During the past few years, special computer codes have been developed for predicting the close-in phenomena of underground nuclear explosions using the laws of physics, and the knowledge of the properties of the materials in which the detonations occur. As a consequence, a better understanding of experimental observations and measurements has evolved.

The effects of explosion-induced ground motion must be evaluated in planning and executing any nuclear excavation project. For some projects ground use intensity may dictate the use of less-than-optimum yields to minimize damaging effects. In remote areas, weighing the alternatives of outright purchase of some property or use of smaller yields may be required. The cost of indemnifying owners against damage must be considered in any case. Discussions of the effects of ground motion on three broad types of facilities - engineered structures, residential buildings, and equipment required for the support of nuclear excavation operations - are presented. A method of predicting the response of single- and multi-storied buildings, the response spectrum technique, is discussed, with emphasis on the application of explosion-induced spectra.

In November 1952 an event took place which was to have a profound effect on political alignments of the world. This event was the detonation of "Mike", the first large thermonuclear device. The political implications of this experiment overshadowed what has come to be a major advance in the development of scientific tools; the experimentally verified, extremely high thermal neutron flux observed in Mike. Subsequent to this observation, the Atomic Energy Commission established a study program to investigate this particular characteristic of nuclear devices. Under the program, Los Alamos Scientific Laboratory and Lawrence Radiation Laboratory, Livermore, have studied the mechanisms of high fluxes, capture systematics, general stability characteristics, and more specifically, nuclear design to accomplish this massive neutron irradiation. Utilization of these greatly increased fluxes can be expected to significantly advance understanding in many fields.

A fraction of the energy released by the underground detonation of nuclear explosives is locally deposited as residual thermal energy. An accurate prediction of this usable fraction of the energy released is necessary to evaluate the feasibility of several of the proposed projects in the Plowshare Program. This paper will present a summary of the available data on residual thermal energy from nuclear detonations in three different geological media: tuff, halite, and granodiorite.

The Chapman-Jouguet pressure and equation of state of the high explosives PBX 9404 and LX04-01 have been experimentally derived. To assure a strictly one-dimensional geometry, spheres of high explosives were used. Experimental measurements of the radius-time history of material accelerated by the explosive gases were used in conjunction with finite difference calculations of the hydrodynamic equations to obtain some previous inaccessible data on high explosives.

The angle errors of a rotary table can be accurately measured by stepping off the angles with an optical caliper and computing table error from (1) the error readings at each angle measured and (2) the cumulative caliper error that will be evident when the circle is closed at 360', eliminating the necessity of adjusting the caliper to the exact setting.

The increasing exponential function e-at [a > 0] characterizes such natural events as gas discharges, neutron multiplication, and the transistor avalanche phenomenon. This report describes an instrument for measuring the rate of rise, a, of an increasing electrical exponential signal.

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.

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.