The guiding center motion and the adiabatic invariants of charged particle trajectories in electromagnetic fields are treated in this review. General and specific theories of charged particle motion are also reviewed.

Antiproton-production and nucleon-interaction cross sections were investigated for antiprotons in the energy range 0.5 to 1.0 Bev. The antiprotons were distinguished from other particles produced at the Bevatron by a system of scintillation- and velocity-selecting Cerenkov counters. The excitation function and momentum distribution were recorded for antiproton production in carbon and compared with statistical model expectations.

Previous attempts to interpret chemical structure in terms of x-electron resonance have been recently criticized. A reinterpretation of the lengths of the C-C bonds in terms of orbital radii has not revealed any effects of x-electron resonance in the ground states of classical molecules such as 1, 3-butadiene, methyl acetylene, etc. Even in a non-classical molecule such as benzene, resonance shortening of the CC bond is only in terms of the strengths of the hybrid orbitals. If the lengths and force constants of the C-C bonds vary with hybridization, so also must their bond energies. If resonance is not important in classical molecules, the heat of atomization of a classical molecule must be given by the sum of either the energies of the bonds or the contributions of the atoms present in it. To test this theory, we have estimated the contributions of some standard carbon atoms, viz., primary, secondary, tertiary, quaternary, trigonal, and diagonal carbon atoms.

An electron can suffer a very large acceleration in passing through the Coulomb field of a nucleus, and in this interaction the radiant energy (photons) lost by the electrons is called bremsstrahlung (also, bremsstrahlung sometimes designates the interaction itself). If an electron whose total energy [formula] traverses matter of atomic number Z, the electron loses energy chiefly by bremsstrahlung. This case is considered here.

It is shown that a radial pressure gradient exists in the silver chloride when it is used as the pressure transmitting medium in Bridgman anvils. The gradient can be obviated by the use of circular sections of wire. The center of curvature of the wire hoop is made coincident with the anvil center. When the inner and outer diameters of the pyrophyllite retaining ring are 1/2 and 7/16" respectively, the pressure, P, is P = (0.725 + 0.468R) L where R is the fractional displacement from the center, and L is the average pressure as determined from the total load and area of the anvil face. The above appears to be valid to 125 Kbars. The Bismuth 6-8 transition is found to accur at 88+3 Kbars.

A carrier-free separation of hafnium from several hundred milligrams of rare earth oxides by anion exchange from saturated HC1 solution is given. The procedure is completed in 4-8 hours and is suitable for remote control work.

Even in its present primitive stage the molecular beam method promises to open up many opportunities for detailed studies of reactive collisions. The early results described here have revealed several features inaccessible to the traditional methods of kinetics. We hope this program of beam studies will ultimately provide the basis for constructing a theory of the molecular mechanics of reactions. By borrowing what are now everyday techniques in nuclear physics (modulation of the beams; mass analysis and counting of detected ions) it appears possible to gain from four to six orders of magnitude.

Molecular sieves are synthetic zeolites which, when dehydrated, contain a network of empty pores and cavities that constitute almost 50% of the total volume of the crystals. They have the unique property of adsorbing within these cavities only those molecules that are small enough to pass through the pores of the crystals, Molecular sieves have a very strong affinity for water and other polar molecules. It is this selective property plus their stability and reasonable cost that make them of interest for the application described herein.

Calorimetric measurements by Rao and Giauque (1960) showed some unaccountable residual entropy in crystals of [formula] at low temperatures. We have investigated the crystal structure in search of an explanation of the disorder. The resulting structure offers no possibility of disordered rings of hydrogen bonds such as were found in [formula], nor do we find any other explanation of the entropy discrepancy.

The crystal structures of the normal fatty acids of low molecular weight have been rather neglected until recently. Formic acid and acetic acid occur in the solid as hydrogen-bonded linear polymers, while several acids with eleven or more carbon atoms per molecule exist in the solid as dimers. The melting points of these acids, when plotted against number of carbon atoms, fall on two rather similar curves for even and odd numbers of carbon atoms, respectively, each with a minimum near five carbon atoms. These facts and hope of explaining the melting-point behavior led us to examine the structures of propionic and butyric acid crystals. These crystals have different structures, but both contain dimers.

"This bibliography lists selected books, articles, and unclassified reports which have appeared in the following abstracts and indexes between August 1959 and December 1960."

This paper discusses a group of high-speed switching circuits using the basic current-switching mode of operation. The first part of the paper presents a dynamic analysis of the basic current-switching mode and the second part is the dynamic and steady-state analysis of a current-switching flip-flop.

The structure and operation of cyclotrons are discussed. Factors limiting cyclotron size and energy are given. Improvements to the basic continuous-wave cyclotron are described, including frequency modulation, strong focusing, and variable-energy facilities.

Figures 1 and 2 summarize total decay energies for the four radioactive series. The alpha-decay energy obtained by measuring the energy of the alpha particle leading to the ground state includes the energy of the recoil nucleus. The curve shown in figure 3 defines in broad outline the conditions and regions of alpha instability. A great deal more is to be learned from a more detailed examination of the region where alpha radioactivity is prominent. Of great value to the experimentalist is that he is able to predict alpha energies, and the agreement between predicted and measured values often serves as a criterion for isotopic assignment. A number of systems for correlating alpha decay energies have been employed, and that perhaps most widely used is illustrated in figure 4. Here the isotopes of each element on a mass number vs. energy plot are joined, resulting in a family of curves which over a wide region comprise a series of nearly parallel lines.

Specimens suitable for transmission electron microscopy have been prepared from bulk polycrystalline molybdenum after tensile deformation and recovery. The resulting dislocation substructures are described. Some tentative conclusions concerning the mechanism of plastic deformation in molybdenum are discussed.

In a previous publication we reported measurements of the momentum spectra of He<sup>3 and H<sup>3 nuclei produced in collisions of 740-MeV protons with deuterium. The He<sup>3 spectrum exhibited an anomaly in the form of a peak in the region corresponding to double pion production. For reactions resulting in a He<sup>3 the two pions (or particle) can be isotopic spin states 0 or 1; if a H<sup>3 nucleus results only 1 = 1 is allowed. We have since repeated the experiment with a new arrangement which enabled us to measure both the He<sup.3 and H<sup>3 spectra with improved resolution and accuracy.

The effect of temperature on the yield strength of the polycrystalline hexagonal Ag-Al intermetallic phase was investigated over the temperature range 77 to 775 K. It was found that the curve for yield stress vs temperature for both polycrystalline Ag-33 at .% Al specimens that were heavily cold worked prior to deformation and those that were recrystallized prior to deformation was parallel to that for prismatic slip in single crystals.

The problem of the natural convection of an electrically and thermally conducting fluid within a long, narrow, vertical toroidal channel centered in a large block of an electrically and thermally conducting solid is analyzed. A uniform horizontal magnetic field is applied to the fluid, and the bottom of the solid block is maintained at a higher fixed temperature than the top. The laminar steady-state single-cell convective motion of the fluid is considered and an approximate solution is found for the heat transfer rate between the bottom and top surfaces of the block in the limiting cases of small and large Hartmann number. A numerical example is given for liquid sodium in which the application of a magnetic field of a few hundred gauss is shown to significantly reduce the rate of heat transfer.

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 …

Based on the assumption that the noise contribution of a semiconductor detector is due solely to the bulk properties of the semiconductor, equations are presented which indicate the theoretical limits of noise in detector-amplifier combinations. These equations show that an optimum amplifier time constant and detector bias voltage exist for which condition the minimum noise is independent of the semiconductor resistivity. The optimum performance of a detector-amplifier system is shown to depend only upon detector area, input capacity (less detector capacity), semiconductor minority carrier lifetime, and the transconductance of the amplifier input tube. A new detector structure including a guard-ring electrode as an integral part of the detector structure is described which largely eliminates noise due to surface leakage. Experimental results for detector leakage and energy resolution are presented which agree well with theory.

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.

This paper reports the chemical and physical properties of the NTA film packet. It correlates with these properties the response of this packet to neutrons of various energies. In this correlation the concept of the track unit is introduced as a basic unit for reporting film-packet response.

The F-48 columbium base alloy maintains useful mechanical properties for structural application up to 2600 degree F. Short-time tensile and creep rupture strengths have been determined for four F-48 plates, each from a different heat and with a different work history. Flow testing in a high-temperature, high-pressure air stream has been conducted to study oxidation behavior of the bare meatal. Auto-ignition is found to occur at a stream temperature of 2600 degree F. The phenomenon appears to be temperature dependent only. Development of an oxidation protection coating, utilizing environmental flow test apparatus, is proceeding.

In previous letters we have reported a Av resonance, called Y*1, observed through the study of the interaction of 1.15-Bev/c K* mesons in hydrogen in the Lawrence Radiation Laboratory 15-in. bubble chamber. We now wish to report the results of the study of the three reactions [formula](1), [formula](2) and [formula](3).