Monthly report the progress and development of improved zirconium alloys for service in superheated water and steam. This report covers the period between April 1 to April 31, 1961 and was conducted by the United States and the European Atomic Energy Community (EURATOM).

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.

Report presenting an investigation of a model of the Republic F-105 airplane to determine the static longitudinal aerodynamic characteristics of a revised configuration. The revisions included a lengthened fuselage, a relocated canopy, a contoured fuselage afterbody, a ventral fin, and an enlarged vertical tail. Results regarding the effect of stores, effect of dive-brake flaps, effect of forebody modifications, gun blisters, and duct air bleed, and a comparison of the modified model with the original are provided.

With the construction of nuclear reactors, a great deal of emphasis has been placed upon studying the effects of radiation on the solid materials of construction. It has become necessary to consider radiation exposure as an environmental entity along with others so established such as temperature, electrical and mechanical stress, chemical resistance, weather, etc. Problems concerning the study of the behavior of materials that are thus increased when radiation exposure has to be evaluated singly or in combination with one or more of the other environments. This paper presents the general plan of attack being followed to solve such problems that arise when plastics and elastomers are placed in radiation fields. These studies were undertaken for two primary reasons: (1) to obtain engineering data for practical applications of the desirable properties of these materials for such devices as o-rings, gaskets, pipe, and electrical insulation; and (2) to use these data to enable a better understanding of the nature of radiation effects on these materials. The initial phase of the program is the screening of materials by subjecting them to various degrading environments and recording property changes. Thus, with data on how these materials performed, more comprehensive studies could be made …

Abstract: "A cylindrical coil has been designed for pulsed field operation suitable for use in a model thermonuclear reactor. The coil has an eight-inch inside diameter and a length of fifty-one inches. Magnetic mirrors at the ends consist of double-layer solenoids six and one-half inches long designed to slip over the main coil. Subsequent models of this coil have been fabricated which improved the electrical insulation provided by the bonding materials and the mechanical rigidity of the coil. Peak central fields of fifteen kilogauss and mirror fields of thirty kilogauss have been obtained."

Abstract: "Aluminum-clad nickel-plated uranium is corrosion resistant in boiling water. Samples with intentional defects in the aluminum-nickel clodding layers, after testing for more than 300 hr. showed no sign of rapid failure. The study of electroplated metals on uranium for aluminum cladding has defined the effects of several processing variables on the corrosion resistance. The quality of the uranium and the quality of the aluminum-nickel bond were important. Heat treatment and vacuum outgassing of the nickel-plated uranium prior to aluminum cladding were beneficial, and minimizing the amount of air present in the hot-press assembly was desirable. Variation in the steps for electroplating on uranium did not affect the corrosion resistance of aluminum-clad uranium."

Memorandum presenting pulse techniques applied to strain gages for increasing the output level and extending the usable range. Bonded and unbonded strain gages which normally operate with exciting potentials between 3.5 and 14 volts operated satisfactorily with 200-volt pulses of 1-microsecond duration and a repetition rate of 350 per second. Results regarding maximum allowable voltages, effective pulse duration, sensitivity, minimum readable signal, effects of cable capacitance and inductance, sensitivity to external noise, and linearity are provided.

Abstract: "A titrimetric method for the determination of fluoride in plutonium is reported. Prior to a steam distillation of the fluoride, the bulk of the plutonium is separated by precipitation of the sulfate. The fluoride in the distillate is titrated at a pH of 3.2 with 0.001 M thorium nitrate, using chrome azurol-S indicator. Applied to samples containing 1 to 15 parts per million fluoride, the recovery is 87% and the precision on the 95% confidence level is +/- 0.65 ppm."

Memorandum presenting an investigation of the effect of the addition of approximately 6 percent nickel, cobalt, or platinum on some properties of molybdenum disilicide. These additions resulted in appreciably lowering the modulus-of-rupture strength from that of unalloyed molybdenum disilicide. Results regarding density and particle-size analysis, chemical analysis of bars, metallographic and x-ray analysis, density and resistivity, modulus-of-rupture strengths, thermal shock tests, and oxidation resistance are provided.

Report presenting an investigation of a silicone-diester blend (SD-17) in various bench studies and in a turbopropeller engine to determine its suitability as a lubricant for aircraft engines. The performance of the fluid was satisfactory during more than 17 hours of operation in a T-38 engine with power levels from 1745 to 2400 horsepower. Results regarding bench studies and turbopropeller engine study are provided.

A survey of experimental data at supersonic speed indicated that shock-induced separation of a turbulent boundary layer will result for Mach numbers of approximately 1.33 or greater when a theoretical stream static-pressure-rise ratio of approximately 1.89 occurs across a shock interacting with the boundary layer. The significance of this tentative criterion for turbulent boundary-layer separation is discussed with respect to the design of supersonic diffusers.

Report presenting the ignition delays of propane-oxygen-nitrogen mixtures as a function of temperature and composition in a flow system. Results regarding the effect of apparatus parameters, effect of propane concentration, effect of oxygen concentration, effect of temperature, and interpretation in terms of slow reaction kinetics are provided.

This technical report is a summary of unclassified theoretical work on propagation of one-dimensional shock waves and on the propagation of spherical shock waves in gases.

Two xenon extraction runs were made this month. It appears that a small design change in Trap #2 will be necessary so that a dry ice-trichloroethylene slurry can be used for coolant rather than liquid freon. For each of the runs this month the enriched generator was exposed for four hours in the est pile operating at 100 watts. A period of eight hours for cooling and xenon builidup was allowed before the collection and separation runs were started.

"A description of the two swept propellers investigated in the Langley 8-foot high-speed tunnel is presented, together with the discussions of the numerous assumptions and analyses on which the designs of these propellers are based. The blades are swept considerably along the entire blade radius and, in order to allow for reductions in the maximum stresses, are swept forward inboard and backward outboard. The blades have been designed on the basis of the blade-element method primarily to have subcritical efficiencies at the highest possible forward speed. The designs have been controlled primarily by the stresses in the blades" (p. 1).

This report covers an investigation meant to find the feasibility of producing corrosion resistant zirconium from sponge by special melting techniques. The zirconium metal has certain required specifications, such as: the metal must be free from bafnium, and it must be free from other impurities of undesirable neutron cross section.

"An investigation has been made of a partial-span model of the tail surface designed for use on the Hughes Falcon (MX-904) missile to determine the aerodynamic characteristics of the tail and elevator including elevator hinge moment. Data obtained at Mach numbers of 1.62 and 1.96 in the Langley 9- by 12-inch supersonic blowdown tunnel are presented for the condition where the tail was attached to a segment of the foreshortened body" (p. 1).

This report contains a selected list of Government sponsored research projects on related aircraft materials in effect during the calendar year 1947. Information is contained on titles, description, sponsoring and conducting agencies.

A general representation of fan and turbine arrangements on a single classification chart is presented that is made possible by a particular definition of the stage of an axial-flow fan or turbine. Several unconventional fan and turbine arrangements are indicated and the applications of these arrangements are discussed.

The importance of fast neutron fission (i.e., fission caused by neutrons before being slowed down) was recognized by Szilard, and calculations similar to the present one have already been carried out by him, Feld, Ashkin, Wheeler, Wigner and others. The purpose of the present paper is to give a general formula for the contribution of fast fission to the multiplication constant, which will include all the cases already considered and will be applicable to more complicated geometries than those considered by the previous writers.

Formulas are given for the propelling or drag force experience in a uniform air stream by an airfoil or an airfoil-aileron combination, oscillating in any of three degrees of freedom; vertical flapping, torsional oscillations about a fixed axis parallel to the span, and angular oscillations of the aileron about a hinge.

"The tests discussed in this report were conducted to determine whether or not there is appreciable vaporization of the fuel injected into a high-speed compression-ignition engine during the time available for injection and combustion. The effects of injection advance angle and fuel boiling temperature were investigated. The results show that an appreciable amount of the fuel is vaporized during injection even though the temperature and pressure conditions in the engine are not sufficient to cause ignition either during or after injection, and that when the conditions are such as to cause ignition the vaporization process affects the combustion. The results are compared with those of several other investigators in the same field" (p. 629).