"The ion source used for hydrogen and deuterium ions in the variable energy cyclotron at the University of Rochester is of the hooded arc type. For the past year it has been operating with a new feature which has greatly improved its performance. The new feature is a magnetic mirror built into the upper end of the arc hood by a simple insertion of a steel bearing ball 1/8" in diameter. The magnetic field gradient near the ball provides a magnetic mirror action on electrons moving up the arc channel toward the ball, reflecting may of them."

Startup accident and pump run-down on the ORR have been simulated on the Reactor Controls Analog Facility. At full flow the 150% level scram (45 Mv) easily terminates the startup accident before the metal temperature gets above 180°F. For very low flows typical of criticality runs, temperature coefficients turn the excursion before it reaches 150% of full power, and temperatures climb to boiling, a potentially hazardous condition. (This same behavior can occur at full flow is the power is increased to the point where the level scram must be set above 50 Mw).

A generalization of Wigner's simple model for the distribution of nuclear level spacings is studied. It is based on a stochastic process which reproduces the correct joing probability distribution of N enerfy levels for small spacings. The case N=3, which includes the effect of the correlation between adjacent spacings, is discussed in detail. The resulting distribution and the correlation coefficient are compared with experimental data. No definite conclusion can be drawn except to say that the effect of the correlations on the spacing distributions on the spacing distribution is very small.

Report providing detail measurements and percentages in charts, using three statistical parameters, for amplitude-probability distributions of atmospheric radio noise.

This report is a working document of the UB AEC Nuclear Cross Sections Advisory Group and is issued about twice a year for the purpose of stimulating important cross section measurements. The requests listed in this report have originated from various Atomic Energy Commission contractors, the Advisory Committee on Reactor Physics, and the Nuclear Cross Sections Advisory Group. The distribution is limited to members of the US Nuclear Cross Sections Advisory Group (NCSAG), the US Advisory Committee on Reactor Physics (ACRP), the Tripartite Nuclear Cross Sections Committee (TNCC), the European-American Nuclear Data Committee (EANDC), to US AEC off-site contractors, and to the requestors and measurers of the cross sections listed in this report. The contents of this document are not to be republished in part or in full without special permission of the chairman of the NCSAG, The unpublished data which appear in this report must not be quoted in publications without permission of the experimenter.

An experiment was performed at the ORR in order to find a good fission chamber location. Two locations on the pool side of the reactor tank were explored with a one inch diameter fission chamber. The thermal neutron flux attention was found to vary nearly exponentially with distance, and no shadowing effect could be seen during a reactor startup. The fission products high gamma flux could be discriminated without difficulties. Both positions seem to be adequate to locate a reactor control fission channel.

The relative yield of neutral photopions from various elements was determined as a function of the quantum limit energy of the Berkeley synchrotron. Single decay photons from neutral pions were observed at 45, 90, and 135 deg to the incident bremsstrahlung in the laboratory system. Mean free paths for neutral pions in nuclear matter were obtained, an optical model prediction of the photopion yields based upon pion-nucleus scattering data was confirmed, and the presence of coherent pion production in the forward direction was detected.

The calculation of concentration transients caused by mixing in the interconnected three-body system of the fuel dump tanks, core and blanket has been coded for the IBM-704. The system of equations includes material balances, the dependence of critical temperature on core and blanket concentrations, and the effect of temperature (density) changes on flow rates. The controllable flow rates, the fuel dump tank weight and the initial conditions are input variables. Outputs include core and blanket concentrations, critical temperature, concentration ratio and power ratio. The code has been used to compute transients during a number of operating situations.

Experimental determination of heat-transfer coefficients, burnout heat fluxes, and friction factors have been made for swirl flow of low-and moderate-pressure water through electrically heated aluminum, nickel, and copper tubes containing full-length Inconel twisted tapes. For nonboiling conditions, swirl-flow heat-transfer coefficient were successfully correlated with both the Froude modulus (the ratio of inertial to centrifugal forces) and a grouping of the Grashof and Reynolds moduli (ratio of buoyant to inertial forces).

The development of a miniature probe was desired for measuring approximate single nuclide beta dose rate in solution and in various animal organs. This probe designed for biological experiments, was to have maximum possible sensitivity to detect low levels of nuclide concentrations. The desired dimensions of the light pipe were to be approximately one-fourth-inch diameter with lengths of three to twelve inches.

In order to prevent dangerous concentrations of combustible gases such as hydrogen and ammonia in Redox dissolvers, a continuous analysis of the off-gases is needed. Hydrogen is evolved from most fuel element dissolution processes now used or planned for use at Redox. Ammonia is also released from ammonium fluoride dissolution of zirconium and caustic dissolution of aluminum cladding. Oxides of nitrogen and hydrogen are formed during nitric acid dissolution of uranium or plutonium-aluminum alloys. Since no fixed ratio exists between the concentrations of any two of these gases, the determination of combustible gases in complex mixtures is not possible with a single bulk property analyzer.

This bibliography contains 145 references on radiation effects on aluminum, elastomers, and lubricants. Also included are references on radiation units and conversion factors. The bibliography is limited to the period 1950 through 1959, with the references arranged alphabetically by title in five categories. An author index is provided. Sources used in compiling this bibliography are: Abstracts of Classified Reports, Bibliographies of Interest to the Atomic Energy Program: Classified and Unclassified Versions, Monthly List of Bibliographies in the Atomic Energy Program. U.S.A.E.C. Technical Information Service Extension, Nuclear Science Abstracts.

The multi-purpose dissolver was designed to provide: 1. A critically safe vessel for dissolving uranium metal of enrichments up to one percent U-235. 2. A vessel which can be charged with fuel elements up to 10 feet long. 3. An off-gas arrangement which will eliminate return of ammonia to the dissolver during the Zirflex decladding process. 4. A vessel in which small charges can be dissolved without using extra chemicals. 5. A by-pass routing around the silver reactor during cladding removal.

Abstract. A systematic procedure for preparing purchase specification on electronic instrumentation or control systems has been developed. This procedure results in preparation of specifications which: 1) make it possible to find any particular specification requirement quickly; and 2) insure that no important requirement has been omitted. Details of this systematic specification preparing procedure presented.