To date limited agreement has been obtained between theory and experiment for 4f to 4f transitions for Tm (IV) (4f12). It is clear from the considerations that have appeared so far in the literature that intermediate coupling is important in the case of Tm (IV). Solutions of the intermediate field equations yield [formula], and [formula]. Experimental agreement to [formula] was obtained.

"This report presents some of the theory of operation of the Mirror Machine, and summarizes the experimental work which has been carried out...The modus operandi of the Mirror Machine is to create, heat and control a high temperature plasma by means of externally generating magnetic fields."

This technical report analyzes an experiment designed to test the theory of seismic decoupling of underground explosives proposed by Latter, LeLevier, Martinelli, and McMillan [1959]. The theory calculated the amplitude of a 1.7-kiloton nuclear explosive in a hole in salt and compares it to the measured value of the 1.7-kt Rainier shot in tuff at the same distance. A decoupling factor of about 300 resulted. The experiment, called Cowboy, was designed to test the decoupling principle by carrying out a series of eight high-explosive shots in two spheres made in a salt dome and nine tamped shots for comparison purposes. The seismic data reported here was obtained primarily at 14,000 and 22,000 feet from the shot at frequencies of 10 to 30 cps. A salt-to-salt decoupling factor of 100 was obtained which is consistent wit the predicted 300 tuff-to-salt factor. When the sphere was over-driven so that the walls did not move elastically (a condition which violates the theory), decoupling factors of 10 and 30 were measured. The report interprets the seismic data to give the dependence of decoupling on the various parameters of the experiment. The decoupling deduced from measurements made 80 feet from the shot points is found …

A series paired explosions in a salt mine near Winnfield, Louisiana, has been conducted to test a theory by A.L. Latter concerning seismic decoupling by underground cavities. The theory predicted a decoupling of 132 Free-field and surface measurements from an explosion in either a 6-ft- or a 15-ft-radius spherical cavity were compared with similar measurements from a completely tamped explosion of equal size. Shot sizes were from 20 pounds up to a ton. Surface measurements were made out to 100 km and covered the frequency range from 0.05 to 100 cps. The experiments confirmed that decoupling does occur. For explosions that produce an average cavity pressure up to one-fifth and possible more of the lithostatic overburden pressure, seismic waves were decoupled by the 100, i.e., two order of magnitude. Even for explosions producing an average cavity pressure of six times the lithostatic overburden pressure, the seismic waves were decoupled by 20 -- more than a full order of magnitude. Minimum decoupling factors as a function of frequency are presented.

A systematic study is made of the electromagnetic properties of charged vector mesons. The various formalisms used to describe charged particles of spin 1 are compared, and a new first-order formulation of the Stuckelberg theory is developed.

The spin of neodymium-141 was measured by the method of atomic beams and found to be 3/2. A lower limit placed on the hyperfine separation of the states with total angular momentum [formula] by second-order perturbation theory shows [formula]. A prerequisite for the determination of the nuclear spin from hyperfine-structure measurements is the knowledge of the electronic structure. The ground-state configuration of neodymium is known and the value is used throughout this work.

Reactivity measurements made by the pulsed neutron technique were compared with results obtained by conventional techniques. The pulsed neutron results were in good agreement with those obtained by stable period measurement and rod drop. Differential effectiveness of partially inserted rods was shown to be well represented by elementary perturbation theory. Finally, the pulsed neutron technique was found to be the only good method for measurement of large reactivity changes.

This revised version contains material published in the two years since the original report was issued in January 1960. The report covers the history of the discovery of fission, fission theory, and the probability of fission. It discusses the distribution of mass in fission, the distribution of nuclear charge in fission, kinetic energy of fission fragments, and the role of neutrons and gamma rays in fission.

The theory of the hydrodynamic origin of cosmic rays proposed by Johnson and the author (Colgate) has developed to the point where the final evolution of a star to the supernova instability and subsequent explosion can be described with sufficient detail such that cosmic rays with appropriate intensity, composition, and spectrum to account for observations are a logical and necessary result. In the first publication it was pointed out that nuclei in the surface of the star may acquire many orders or magnitude more than the average energy per particle released in the explosion because of the large ratio of matter density between the core and the outer mantle. A shock from a sudden pressure increase in the core intensifies as it advances into lower-density material, thereby imparting extreme relativistic energies to the outermost layers. The shock wave was assumed on the basis that the observed explosion occurred in a time short compared to the traversal time of sound across the dimensions of the star. It was argued without proof that an adiabatic process would be inconsistent with the accepted gravitational instability as the trigger mechanism. In an attempt to confirm this supposition we extend the hydrodynamic calculations to describe …

The absolute differential cross sections for elastic scattering of 31-Mev He3 ions on Be, Al, Cu, Sn(nat), Sn120, and Bi have been measured in the angular range of approximately 10 to 120 deg in the center-of-mass system. Thin self-supporting foil targets were chosen to span the parameter A 1/3, where A is the target mass number. The first excited states of the isotopes of the above elements had sufficient energy separation from the ground state to enable elastic scattering to be resolved from inelastic scattering. The detection system, consisting of Cal(Tl) scintillation crystals, was capable of 3%pulse-height resolution and 1 degree angular resolution. Characteristically, the light-element angular distributions show strong diffraction effects. The differential cross section divided by the Rutherford cross section decreases exponentially at large angles for the heavy elements, and the differential cross sections break away from Rutherford behavior at angles which increase almost linearly with increase of atomic number of the target nucleus. A comparison of the results for natural tin, and tin enriched to 85% in Sn120, indicated that within the experimental uncertainties over the measured angular interval, there were no pronounced isotopic effects. The data are presented both in tabular and graphical form to allow …

This report is a corrected copy of the authors "rapporteur talk" at the 1959 Kiev Conference on High Energy Physics. It contains data on the rapporteur system and on interactions of strange particles with protons and neutrons, using data from bubble chambers, counters, and emulsions.

Thesis describing the Auger effect in the heaviest elements. The elements detailed in the report are ytterbium, polonium, and uranium. Measurements of K fluorescence yields and K Auger electron intensity ratios are given.

Thesis discussing the study of deuterons produced at wide angles to a beam of 300 Mev neutrons and a beam of 300 Mev protons. It was observed that the deuterons are formed by "a two step process in which the incident nucleon, or its collision partner, is scattered and then picks up in the same nucleus." Some tritons are also observed, and it is thought that they are formed by the same process as the deuterons. From these findings, the author concludes that "for heavy nuclei, there is a nuclear skin rich in neutrons."

Abstract. The cross section of photoneutron production in Be9 at energies of 1.692, 1.720, and 1.78 Mev has been investigated using radioisotope gamma-ray sources. Neutron counting was by manganous sulfate bathe and a long counter. Gamma-ray counting was by a scintillation spectrometer consisting of a NaI(T1) scintillation crystal and a 256 channel pulse-height analyzer. A theoretical treatment of the P [right arrow] S transition near threshold using square-well potentials is also presented.

Thesis describing a research conducted to extend observations on nuclear energy levels and how they effect the nucleus itself, and an investigation on the gamma rays associated for the even-even isotopes and to obtain additional data for the oddmass neclei in the hope that more regularities will become apparent for that class of nuclides.

Report discussing "experimental results on the classical stabilized pinch," "the usefulness of the Levitron in Stellarator-type operation," and "practical details of the levitation process." A configuration is presented which involves a "toroidal pinch tube inside which a rigid toroidal conductor is levitated by means of an induced magnetic field." Additionally, "an alternative scheme is considered, where the toroidal core is suspended from current-carrying wires, but this approach does not appear promising."

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.

From introduction: "This article constitutes the third of a series of three papers on the "direct" measurements of the meson masses by the "Hp vs. Range" mass ratio method...The study here reported is a logical extension of the pion-proton mass ratio technique."

In this paper, a theoretical solution is developed for the transient thermal stress distribution in a reactor fuel tube of circular cross sections with spatially uniform internal power generation and forced convective heat transfer at the inner surface of the tube. Solution of the equation of heat conduction is done my means of a Laplace transform with subsequent application of the inversion integral to arrive at a final expression for the transient temperature distribution. The solution is of interest in the analysis of transients in reactors which use either a gas or liquid heat transfer medium. The work was initiated in conjunction with the quench testing of ceramic fuel elements for a gas-cooled reactor. Expressions for the component stresses are given explicitly and examples of application of these formulas to startup of a gas cooled reactor and the flow quenching of a fuel tube are given.

This paper reports an extension of previous experimental work with Alfven waves. We consider hydromagnetic waves propagating in a cylindrical plasma in a uniform axial magnetic field. The copper tube is filled with highly ionized plasma by an electrically driven switch-on ionizing wave. After the tube is filled with plasma, a hydromagnetic wave is induced by a radial current flow from the small molybdenum electrode to the copper tube. The force produced by this radial current together with the static axial magnetic field displaces the plasma in the azimuthal direction, and a transverse wave is propagated in the axial direction, along magnetic field lines. The transient magnetic field associated with the wave is also in the azimuthal direction.

This report follows the radiochemical study of fission and spallation products produced by bombardment of U-235 with 18- to 16-Mev helium ions and of the spallation products produced by 8- to 23-Mev deuteron bombardments of Np-237.

Abstract: "Microwaves have been used for several years at Lawrence Radiation Laboratory to study conditions in the magnetically contained plasmas of controlled fusion research. There are two basic microwave techniques. One gives information on electron density and distribution in the plasma, the other provides data on electron temperature. This paper briefly summarizes the established techniques, discusses engineering requirements and limitations, and describes some further applications of microwaves presently being considered."

Abstract: "The elastic double scattering of deuterons by complex nuclei has been investigated experimentally. Measurements were made on carbon, aluminum, and copper at around 157 Mev; on lithium, beryllium, and carbon at around 125 Mev; and on carbon and aluminum at 94 Mev. The expected tensor components of the deuteron polarization have not been observed. Measurements have been made of the differential cross section and vector-type polarization as a function of angle for the scattering of deuterons from the above elements, at the above energies. The observed polarizations were larger than would be expected on the basis of the individual nucleon-nucleus interactions. In a second experiment we measured the 169-Mev proton-proton polarization at 10, 15, 22.5, 30, and 35 in the laboratory system. The results indicate that partial waves up to and including L = 3 are important at this energy."

Abstract: "A dc magnetic mirror machine has been built and tested by the ARC Research Group. Radiofrequency enhancement has been included in the design through the use of rf plates in the vacuum chamber of the machine. For the proton beams of the order of 1[mu]a, the mirror action has been observed as a function of both the rf voltage and the magnitude of the mirror field relative to the main magnetic field. Current measurements were performed with the aid of a Faraday cup with suitable bias grids."