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.

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.

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.

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.

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.

Plus-minus ratios for pion production by 340-Mev proton bombardment were measured at 13 Mev, 18 Mev, and 42 Mev with the use of the spiral orbit spectrometer.

One of the techniques by which highly ionized plasmas can be generated in the laboratory makes use of strong, electromagnetically driven shock waves propagating into a cold gas. In this paper the phenomenon is analyzed as a one-dimensional single-fluid hydromagnetic problem, neglecting dissipation behind the wave. We hypothesize that the rarefaction wave remains attached to the front. In the limit of essentially complete ionization behind the front the problem can be solved analytically as long as the transverse magnetic field there remains small compared with the longitudinal field.

This paper describes the method developed and the results obtained in an extensive program of measurement of the masses of charged pions. Measurements were made of the total ranges in nuclear track emulsion and the momenta (obtained from the curving of the particle trajectory in the magnetic field of the 184-inch cyclotron) of pions and protons of nearly the same velocity.

A displacement of energy levels has been observed in the K=O band of odd-odd deformed nuclei. It is shown that this shift is due to a particular type of scattering in which the final state is obtained from the initial state by a rotation of 180'. This circumstance allows one to state certain selection rules on the parts of the n-p residual interaction responsible for the shift. The Wigner component of the force cannot contribute to the shift. In certain cases the contribution of all central forces will be strongly damped allowing observation of the tensor force scattering contribution. Numerical results are presented.

Report on UCRL progress in general physics research and accelerator operation and development.

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).

The problem of the reduction of an arbitrary truth function to the minimal union of basic cells is discussed. The solution to this problem has applications to pattern recognition and logical circuit design. An algorithm is presented that solves the problem and generates the class of minimal unions. It partitions an arbitrary truth function into a well-defined set of subfunctions (components) in such a way that the partition is invariant under all transformations that preserve the topology of the original truth function.

It is possible to generate a relatively uniform, highly ionized plasma by passing a powerful discharge between electrodes so arranged that the current is forced to flow across an initial strong magnetic field. The magnetic induction due to the discharge causes a bending of the original field. If the discharge is operated with a low-impedance current source, the electric breakdown starts in a limited region near the current-input connections (minimum-inductance path) and propagates as a well-defined front in the manner of a hydromagnetic shock wave. In this paper we analyze the phenomenon as a one-dimensional single-fluid hydromagnetic problem, neglecting dissipation behind the wave.

During the past five years, potentialities of space travel have greatly increased and new knowledge has become available regarding the nature of cosmic radiation. In the present article the knowledge pertinent to dose evaluation is reviewed for conditions of flight in space in the vicinity of the earth but away from the influence of its atmosphere or magnetic field. Certain properties of the heavy nuclei are also discussed as well as some of the available information on their actual biological effects. Development and completion of the new Heavy Ion Linear Accelerator allows extension of quantitative biological work with these particles. Finally, the statistical nature of the hazard from cosmic radiations and the limitations of space flight due to such rays are discussed.

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.

Over the past 13 years a considerable body of data on explosive cratering has been developed for application to nuclear excavation projects. These data were obtained from some ten cratering programs using chemical explosives (TNT or nitromethane) and seven nuclear cratering detonations. The types of media studied have ranged from marine muck to hard, dry basalt, although most effort has been devoted to craters in NTS desert alluvium and basalt. Considerable effort has also been devoted to the study with chemical explosives of the use of linear explosives and rows of point charges. This paper is intended to be a summary of these data and a statement of the understanding which has been developed from them.

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 development of high-energy charged particle accelerators such as the Bevatron and of improved nuclear-event detection devices such as the Berkeley 72-in. hydrogen bubble chamber has greatly increased the need for high-speed data reduction of nuclear events. Full exploitation of the potential of the 72-in. bubble chamber demands a very high-speed analysis system. This paper describes an approach to such a system.

LRL has the responsibility of demonstrating the feasibility of a reactor for use as a power plant for a low-altitude, high-Mach-number missile. This reactor is literally a very high power air heater which must work at temperatures in excess of 2000' F. The reactor is exposed to high loads so one of the primary problems is providing high temperature structure. Considerable effort has been devoted to developing ceramic structural elements. One of the materials considered for this purpose is silicon nitride. In ceramic structural elements operating over large temperature ranges, a major problem is coping with thermal stress. In this respect there is a similarity with the radome problem. The work on silicon nitride at LRL consisted of limited fabrication studies (principally for familiarization), measurement of properties of interest to the application, and funding of fabrication scale-up efforts.

Quarterly progress report for the Chemistry Division of the University of California Radiation Laboratory: nuclear chemistry, bio-organic chemistry, metals and high temperature thermodynamics, basic chemistry, and chemical engineering.