A better understanding of the maximum operating characteristics that can be achieved with the use of UO2 as a reactor fuel is the primary purpose of this program for Euratom and the Atomic Energy Commission. During this program work will be undertaken in two areas that have been of concern to the reactor core designer for a long time, viz. fission gas release and central melting in fuel rods.

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.

It is shown that the annihilation rates of positrons in metals can be correlated to a good degree by a simple model of the annihilation process based on an assumption that the fractional number of electrons available for annihilation varies as the inverse of the atomic volume of the metal.

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.

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.

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 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.

"A series of glass compositions containing uranium oxide was investigated to determine fiberizability and physical properties of resultant fibers. The basic properties to be determined were the maximum U/sub 3/O/sub 8/ content in a fiberizable glass and the maximum service temperature of the fibers. Glasses containing 60 wt% U/sub 3/O/sib 8/ were fiberizable; the fibers had strengths of 100,000 psi at 1600 deg F. Fiber-forming equipment was installed at Moun Laboratory to produce glass fibers containing PuO/sub 2/. Fibers were successfully formed in the first trials. For additional work a series of base glasses were provided affording a wider range of both PuO/sub 2/ solubility and physical properties."

"The behavior of charged particles in a plasma-free cusp field, or in a cusp field where there is very little plasma, is studied. The numerical computations described may provide a valid picture of the behavior of particles outside such a body of plasma or in the early stages of creation of such a cusped plasma in the low- beta limit. The computations provide a striking illustration of orbits which neither have constant magnetic moment nor behave so irregularly as to defy explanation."

Single record data listings taken during aerial gamma-ray and magnetic surveys of the Brainerd quadrangle in Minnesota.

Average record data listings taken during aerial gamma-ray and magnetic surveys of the Brainerd quadrangle in Minnesota.

A report regarding an airborne gamma-ray spectrometer and magnetometer survey of the Brainerd Quadrangle, Minnesota

A guide for operators of the vehicle-mounted TU-5-A gamma-ray logging unit.

From abstract: "To investigate the deviation of the internal conversion coefficients of E2 transitions from theoretical computations and their dependence on nuclear deformation, the total internal conversion coefficient of the 121.8-kev 2+-0+ transition in ellipsoidal Sm152[over]90 was measured to be 1.135 ± 0.010 with a high accuracy coincidence-sum method. The K-shell to total internal conversion ratio was determined to be 0.588 ± 0.003 with a [beta] spectrometer...The experiment revealed no deviation from theory nor indications of strong dependence on nuclear deformation; it therefore did not confirm recent beliefs in this regard. The details of the coincidence-sum method were described. The K electron to total electron capture ratio, from Eu152 to the 1.53 Mev state in Sm152 was also measured to be 0.79±0.02."

From abstract: "The high temperature enthalpies of five rare-earth metals were measured from 0° to 1100°C using a Bunsen ice calorimeter. The enthalphy of yttrium metal was studied from 1100° to 1675°C using a modified high temperature vacuum Bunsen calorimeter. The data were fitted to empirical equations from which the heat of transition and fusion, the heat capacity, and the related thermodynamic quantities were calculated. These results confirmed indications from other properties that europium and ytterbium metals are primarily in the divalent state.Small anomalies observed in europium were attributed to transitions between electronic states when some trivalent ions occur in these metals. The entropy of the fcc-bcc transition for ytterbium was found to be approximately two-thirds that of the other rare-earth metals for which a close-paced to body-centered cubic transformation has been observed."

Technical report. From Abstract : "Several hundred long, thin-walled uranium tubes were extruded to close dimensional tolerance by a potentially low cost fabrication process in commercial facilities. The principal process steps were; forging uranium ingots, machining the forged ingots into billets, and extruding the billets into tubes. Some 750 tubes (maximum dimensions: 3.5 inches in diameter and 15 feet long) were fabricated by this process. Dimensional control was excellent in that 88% of the tubes were within +/- 0.010 inch of average dimensions over their entire length."

Technical report. From Abstract : "Optimum conditions were determined for the precipitation of neptunium (IV) peroxide from nitric acid solutions. The results indicate that the precipitation could be applied successfully on a plant scale. ... Two crystalline modifications of the peroxide were prepared; these two crystalline structures were similar to structures previously reported for plutonium peroxide."

Abstract: Hydrodynamic flow studies were conducted on a full scale model of the SM-2 reactor vessel and core. Test fluid was water at 200 psi and 200 degree F. Test facilities, model, and instrumentation design are discussed. Flow distribution in the stationary fuel elements, lattices, and control rods of the second pass was investigated. Pressure losses through the various core components were measured and are compared with calculated values. Observed over-all pressure drop was 71 feet of water at 200 degree F, 31% higher than predicted, part of which was due to presence of instrument leads. Element to element flow distribution varied approximately +-8% from pass average. Channel-to-channel stationary element flow distribution varied approximately +-10% from element average and control rod flow distribution varied from +-8.9% to +-6.4 and -11.6% depending upon rod locations. These variations exceed the original goals of a +-10% and +-12% combined deviation for stationary and control rod elements respectively, but are satisfactory in relation to thermal design. There was no indication of unsatisfactory structural performance of any components under hydrodynamic loadings up to 130% of design values. The test program was terminated after determining flow distribution in the reference core design, omitting any work on …

Quarterly report documenting progress on a project to determine an improved zirconium alloy for service in superheated water and steam. This report describes the results of approximately 75 compositions that were prepared prior, and presently are being arc-melted and fabricated into corrosion specimens, continuing the investigations of the effect of zirconium purity and heat treatment on corrosion and resistance.

The following report summarizes the known information to date of June 1961 on the Sand Range as it pertains to the Shoal experiments.

Abstract: "Weights of linear high-explosive charges fired on the Yucca Lake playa of the Nevada Test Site varied from 0.23 to 42.7 pounds per foot. Crater and ditch dimensions and volumes resulting from these shots, fired during the fall of 1959 and spring of 1960, are presented here as a function of charge burst depths. Scaling relationships determined are as expected; i.e., square-root scaling of linear-charge weight per foot for ditch width and depth and a direct linear-charge weight relationship to ditch volume are obtained. Permanent ground surface displacement varies as the -3.22 power of the scaled distance from the charge. Detonation effects, charge shape effects, ditch erosion, and ditch cross sections are discussed. The appendixes present Toboggan data, results of soil investigation, and mathematical treatment given the data."

From introduction: This report summarizes the work that was done at the wells and brings together the available data on depth to bottom, depth to water level, discharge rate, and draw-down for each well, together with coefficients of transmissibility determined in aquifer tests.

From abstract: This report describes analytical and development work in connection with the Pebble Bed Reactor concept. The principle involved in the reactor is the heating of graphite pebbles by the fission of contained uranium and transfer of the heat generated to helium which is circulated through the permeable bed.

From abstract: In this report a consistent set of U-235 partial cross sections for use in the analysis of thermal or intermediate reactor systems has been provided.