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 …

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.

Use of that portion of the characteristic curve of photographic film in which transmission is linear with log exposure eliminates the distributional error and thus makes possible the assessment of total mass of an inhomogeneously distributed cell consistent without scanning or measuring the cell's projected area. Measurement consists of obtaining the difference in output of a photocell receiving the total light transmitted by a photomicrograph of the cell, and a photomicrograph of the microscope field illumination against which the cell was photographed. A method of making such measurements is given, and its basis is described.

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.

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.

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.

The neutron-deficient yttrium isotopes Y82, Y83, and Y84 have been produced by irradiations with the Berkeley heavy-ion linear accelerator. Where possible, identifications were made by establishing genetic relationships with known daughter or granddaughter activities. The half-life of Y84 determined by direct decay is 39+-1 min. By a series of timed chemical separations, the following half-lives have been established: Y82, 9+-3 min; Y83, 8+-2 min. No information pertaining to the radiations emitted in the decay of three yttrium isotopes, other than Y84, has been obtained. The gamma-ray spectra of Y84 and Sr83 are shown.

Two types of apparatus are described for measuring the absorption spectra of metal-ammonia solutions with the Gary Model 14 Spectrophotometer. One apparatus was used for dilute solutions at -70'; the other was used for more concentrated solutions and had provision for holding the solutions at any temperature between their boiling points and -70'.

The power of nuclear track research emulsion as a fast neutron dosimeter is examined in the exposure of a human phantom to PuBe neutrons. Semiautomatic track scanning and high-speed data analysis obviate the major disadvantages of this dosimeter, and allow the following basic information to be obtained without a serious cost in time: the rulative proton recoil energy spectrum, the absolute differential proton track den sity spectrum, and the average proton recoil energy at various locations in the phantom. From this are calculated the total absorbed local tissue doze due is proton recoils, the local thermal neutron intensity, and that portion of the tissue doze due to thermal [formula] tracks.

Recoil ranges of C11 from the reaction C12(p,pn)C11 are presented for incident proton energies from 0.25 to 6.2 Gev. From these data it is concluded that a neutron evaporation mechanism cannot be the major mechanism. The result for incident energies of 3 and 6.2 Gev are consistent with a fast reaction consisting of a single inelastic nucleon-nucleon collision. Assuming this mechanism, an average kinetic energy of 19 Mev can be deduced for the struck neutron (before the collision) in the C12 nucleus.

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.

Of the saturated hydrocarbons, isobutane represents the simplest case where specificity in radiolytic behavior owing to structural configuration should be apparent. The hydrogen bonded to the tertiary carbon atoms should, on the basis of bond strengths alone, be expected to be more reactive than other hydrogen atoms in the molecule. In order to investigate such specificity, liquid isobutane has been irradiated at 20' and an attempt made to identify and measure all products through the C8 (C<sub>8) hydrocarbons.

Several investigators have found that the resistance to heat transfer at certain metal-metal interfaces is dependent upon the direction of heat flow across these interfaces. This paper shows that such a phenomenon can be explained by application of the theory of heat conduction in the solid state.

The second and third law methods of thermodynamics are used to obtain the enthalpies of vaporization of the halides of Be, Mg, Ca, Sr, Ba, Zn, Cd, Hg, Sn, Pb, Ti, V, Cr, Mn, Fe, Co, Ni and Cu. Molecular and free energy data necessary for such calculations are presented. The structure of bonding in these molecules is briefly discussed.

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.

The increasing popularity of liquid-hydrogen targets in physics research has emphasized the need for containers with maximum beam transparency (i.e., thin walls and low Z) and suitable strength at cryogenic temperatures. Fabrication of a Mylar container satisfying these requirements is described here.

A need for a small vertical cylinder-type furnace arises frequently in the Chemistry Department at the Lawrence Radiation Laboratory (LRL). Adequate heat is the major requirement; close control or calibration is not usually necessary. A heating unit of this type can either be used for quickly concentrating solutions in centrifuge cones or, by the addition of a refractory pedestal--can be made into a crucible furnace for size 0 and 00 crucibles. Because much of the chemistry done at LRL is with radioisotopes, disposal of contaminated equipment is an important consideration. In general, furnaces are difficult to decontaminate, hence there was a need for a disposable type. Because nothing meeting the requirements seemed to be commercially available, the Health Chemistry Department made up a simple furnace that has proved useful.

A system for scintillations from nuclear events has been developed and is presently in use at the Lawrence Radiation Laboratory. This paper primarily describes the pulsed light source used to simulate nuclear events; it also describes the necessary nanosecond pulse techniques to measure the light source parameters and to operate large numbers of lamps. Considerations concerning distribution networks are shown. Use of the light source as a spark gap trigger is also discussed.

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.

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.

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.

This system presents a method for making remote sealed-bag passouts from a multicurie-level chemistry processing enclosure. In addition, the polyethylene bags are changed remotely without exposing contaminated surfaces while always maintaining a low leak-rate seal. Our system employs an interchange box (the Passout Box) attached to the chemistry enclosure. Integrated with the box is a hydraulically operated jack that raises and lowers the bags, and a welder-cutter for sealing them. A single master-slave manipulator teamed with the above units handles all operations.

The purpose of this Note is to point out the advantages of the sideband technique over the derivative method in wideline NMR spectroscopy. In the sideband technique the absorption spectrum is recorded directly and the modulation amplitude is no longer a determining factor in the resolution.

It is shown that under very simple and general assumptions the existence of an antiunitary reflection transformation and the charge gauge group implies the existence of an antiparticle corresponding to a given charged particle. Similar consequences follow on replacing the charge gauge group by the baryon gauge group. No assumptions as to specific wave equations, or indeed the existence of local fields, are made.