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.

Presented at session S-1 of the Tenth Annual International Conference on High-Energy Physics, Rochester, New York, August 25- September 1, 1960. The analysis of the latest experiments on p-p scattering at 210 Mev makes it probable that there is a unique set of phase shifts at this energy. Under reasonable assumptions about continuity of the phase shifts and the behavior of the higher partial waves, it is possible to pick a unique solution also at 310 and 95 Mev. This opens a new era in the analysis of nucleon-nucleon scattering, which should lead to a unique model for the scattering matrix up to 400 Mev. Theoretical attempts to calculate a "meson potential" from field theory have not been successful, and the semi-phenomenological potential models, although now in good qualitative agreement with experiment, are not quantitatively reliable. Instead of using these models as a basis for an energy-dependent parameterization of the scattering matrix, as was done by Breit and his collaborators, it is here argued that the Mandelstam representation offers a more reliable starting point. A formalism is developed which allows the one and two pion exchange interaction to be included exactly and gives a Lorentz-invariant description of the rest of …

The cross sections for coherent and incoherent scattering of neutrons from polycrystalline materials are discussed. It is shown that the incoherent elastic, incoherent inelastic, and coherent elastic cross sections may be calculated with negligible error using a simple Debye model to give the phonon spectrum. the criterion determining the correct Debye parameter to use is discussed, and it is emphasized that it is important to allow a temperature dependence in this parameter in order to take account of the temperature dependence of the phonon spectrum. The Debye model is not really adequate to calculate the coherent inelastic cross section and gives results which may be in error by about 15% at very low incident energies.

The present studies are carried out in order to elucidate the effect on enzyme activity of different kinds of radiation. Beams of protons and alpha particles from the Berkeley 60-inch cyclotron and beams of accelerated nuclei of helium, carbon 12, oxygen 16, and neon 20 from the Berkeley Heavy Ion Linear Accelerator (HILAC) have been used. With this variety of particles it has been possible to cover a range of LET 10 times greater than previously utilized in similar studies. The unattenuated energy of the different particles is exactly 10 MeV per nucleon for the HILAC radiation and approximately this value for the cyclotron radiation.

A general method is suggested for analyzing the scattering of particle A by particle B, leading to three or more final particles, in order to obtain the cross section for the interaction of A with a particle which is virtually contained in B. Binding complications are absent if a plausible assumption about the location and residues of poles in the S-matrix is accepted. The method is useful for unstable particles from which free targets cannot be made; the special examples of pion and neutron targets are discussed in detail.

The writer has initiated a comprehensive program of equipment development designed to give the maximum practical aid to the physicists and technicians who are carrying out track measurements. Some attention has also been given to developing systems of data handling using International Business Machine (IBM) equipment and Keysort cards. In addition, some of the steps to insure the accuracy of the emulsion data are taken long before the emulsion is studied under the microscope.

FLOSS III is a third-generation version of a digital computer program which solves a one-dimensional difference representation of the momentum, energy, continuity, and state equations for turbulent, compressible gas flow in equivalent hydraulic channels. Extensive use of this program has been employed in the design and performance analyses of Pluto-type nuclear heat exchangers, and in the specific case of the Tory II-A test series, agreement was obtained to better than 5% for all experimentally measured parameters. The NOMAC and DASH-N programs combine the effects of up to thirty varieties of channels with the dependent boundary conditions imposed by a common inlet diffuser and exit nozzle. The resulting calculations yield performance information for blow-down facility and ramjet flight condition application of the heat exchanger.

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.

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.

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.

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.

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.

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.

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.

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 calculation method has been developed in order to correlate continuous-flow extraction results in mixer-settlers with rate data for batch experiments. This correlation utilizes dynamic extraction coefficients (E's) that are calculated from the rate data and the equilibrium extraction coefficients. The dynamic coefficients may then be used in stage-by-stage calculations, or their average values used in equations derived herein from the overall performance of center-fed columns.

Recent studies on the separation of cobalt and nickel and on the behavior of iron in hydrochloric acid on Dowex-1 resin in relation to the selective adsorption of chloride complexes of these elements have suggested the use of resin for the separation of iron and cobalt.

This report describes the design and testing of a 1.17-Bev/c separated K{sup -} beam designed in the fall of 1958 in connection with a 15-in. hydrogen bubble chamber experiment.