"Experiments are continuing to determine the cleaning efficiency and rate of cleaning of fine size bituminous coals by the water fluidization method. By radio-tracing neutron activated pyrites, data were obtained on the rate of segregation of mineral impurities from the coal as a function of particle size and density in a 48 x 0 mesh hydraulic fluidized coal bed. Two methods of radio- tracing were demonstrated. The ultimate cleaning efficiency of the above size coal is also reported."

"The experimental technique was checked out and the equipment put in working order for the study of the capacity and efficiency of the hydraulic cleaning of coal by water fluidization. The method to determine operating capacity consists of determining the segregation rate by dynamic tracing of radioactive mineral impurities of various size and density ranges, that are injected into the fluidized bed of coal. The equilibrium position of the injected tracer in the fluidized bed of solids is also determined. Obtaining capacity and efficiency data, as needed for design of commercial units, is very much less expensive and much more rapid than operation of a continuous flow pilot plant to get the same data. The required tracer solids were prepared by neutron irradiation of selected fractions of mineral impurities and the experimental work with these tracers is now in progress."

"Results of molecular studies showed that, depending on the chemical composition, polyphosphates are either linear or branched flexible chain molecules. The branch points were easily destroyed by hydrolysis. Hydrolytic stability studies showed that the rate constants are much smaller for the splitting of internal bonds than for the hydrolysis near the chain ends, where both monomeric and trimeric rings are formed. The kinetic study of the degradation of sodium pentaphosphate was continued. Preliminary results indicated that, in the absence of calcium, the formation of each trimeric ring is accompanied by the formation of two orthophosphate rather than one pyrophosphate molecule. The influence of different univalent cations on the behavior of polyphosphates was studied by electrophoresis, conductivity, membrane equilibrium, and viscosity measurements. The effects of divalent ions were also studied."

"Gel contents can be obtained with polyethylene swollen with inhibitor- free allyl acrylate or inhibitor-free allyl methacrylate at a dose of only 0.05 Mrads Using Co/sup 60/ as the radiation source, allyl methacrylate gives higher gel content than allyl acrylate under similar conditions. icant and continues after Co/sup 60/ irradiation has been completed. Monomer desorption after a dose of 1.2 Mrads is less than after 0.05 Mrads, and does not continue after irradiation is stopped. Gel contents can be obtained without prior equilibrium swelling of polymer--monomer mixtures by irradiating the polymer in the presence of the monomer in a nitrogen atmosphere. By irradiating under these conditions with prior equilibrium swelling, gel fractions appear to be higher than those normally obtained. Gel contents of irradiated equilibrium-swollen polyethylene/ allyl acrylate and polyethylene/allyl methacrylate increase with increasing radiation dose from 0.05 to 1.2 Mrads. Gel contents of 1.2 Mrad irradiated polyethyleneallyl methacrylate systems containing various initial amounts of monomer, increase with increasing monomer content. Polypropylene can be radiation crosslinked to give over 40% gel by prior equilibrium swelling with allyl acrylate or allyl methacrylate. "

"Work accomplished in incorporating plutonium oxide in glass and glass fibers between July 1960 and March 1961 is summarized. The purpose of producing plutonium bearing glass and glass fibers was to eliminate or reduce the radiological and toxicological hazards associated with plutonium. Initial results using "wipe" tests showed no removable alpha contaminant in freshly prepared samples. Leaching studies were made using water, dilute HCl, and HNO/ sub 3/. The amount of PuO/sub 2/ leached from the glass can be greatly reduced by substituting Al/sub 2/O/sub 3/, CaO, and K/sub 2/O for much of the Na/sub 2/O component in the glass composition."

"Gel contents of irradiated polyethylene previously swollen with fourteen different di- and tri-functional monomers were accurately measured. Eight of these monomers are useful in reducing the radiation dose required to induce gelation. Allyl acrylate and allyl methacrylate produce the largest gel fractions (approximately -40%) after a dose of 1.2 mrads on the Co/sup 60/ source; these two monomers also swell polyethylene to a greater extent than the others. The degree of desorption of the above monomers from polyethylene during irradiation were measured. Machine irradiation of polyethylene-- allyl acrylate and polyethylene -- allyl methacrylate systems give higher gel contents (approximately -60%) than are obtained under Co/sup 60/ irradiation conditions. This is probably due to the fact that desorption of these monomers is less under machine irradiation conditions. Continuous reswelling and reirradiation of polyethylene-- allyl acrylate and polyethylene-- allyl methacrylate systems give gel contents of about 80% after four cycles. After each cycle, an increased amount of monomer is incorporated into the Polymer by swelling, while the increase in gel content becomes smaller. Swelling ratios of irradiated polyethylene-monomer combinations were also measured."

"Mass spectrometer monitoring of peaks upon flashing the target in measurement of CO photodesorption from W indicates bulk heating to be a main contribution to desorption. Study of auger electron ejection from absorption of O on W yields good agreement between calculated and measured values for electron ejection. Values for O adsorption on W are compared with other determinations, and wide variations in sticking probabilities are noted. Measurements of the conversion of O incident on W ribbons to WO/sub 3/ are found to differ considerably from other determinations. Efforts to eliminate spurious effects in the studies are discussed, and the probability of Auger electron emission is determined not to exceed 1.3 x 10/sup -9/ electrons per molecule absorbed, 10/sup 5/ less than earlier estimates. Difficulties in obtaining clearly defined flash filament adsorption data for CO on W permit only determination of an upper limit of 10/sup -8/ electrons per molecule adsorbed for the maximum efficiency. Studies of inelastic electron collisions with N/sub 2/, H/sub 2/, CO, H/sub 2/O, and CO/sub 2/ gases on W surfaces reveal inelastic and superelastic peaks for water vapor, only an inelastic peak for H, and unexpected absence of inelastic peaks in N/sub 2/ and CO."

"The use of SiC in conjunction with an electron multiplier was found to offer good possibilities for a cold electron ion gage. A helium cryopump with 50 1/sec pumping speed was developed that is capable of maintaining a static system at pressures below approximates 5 x 10/sup -11/ torr with only about one liter of liquid helium every 8 hr. Additional results are reported in photon desorption experiments from tungsten and glass, hydrogen absorption on tungsten, and oxygen adsorption on tungsten. Studies were begun on photon desorption using a field emission microscope and on the interaction of electrons at surfaces. Studies are being continued on the outgassing characteristics of metal systems operating at elevated temperatures."

"Investigations were continued with zeolite traps. Results indicate that certain gases are not trapped by zeolite and must be removed by ion pumping. In experiments to obtain a cold electron source ion gage, output electron currents of several milliamperes were obtained using SiC in conjunction with an electron multiplier. Fundamental surface reaction studies were continued on photodesorption of CO from W, O adsorption on W, H solubility in W, and inelastic collisions of electrons at surfaces."

"Activities in an investigation of basic phenomena associated with particle interactions at surfaces are reported. Development of components, which may be of interest to others working in ultrahigh vacuum research, for use in the research program is described. Work in development of components and techniques was directed toward investigations of non-refrigerated traps, a cryogenic pump using liquid He, and development of electron sources. Research on interaction of particles at surfaces was devoted to photodesorption studies, O adsorption on W, and H interaction with system walls. The study of basic phenomena limiting the attainment of ultrahigh vacuums is being approached by mass spectrometric studies, negative ion formation in H and H/sub 2/O, and outgassing of stainless steel systems."

"Further experiments with the zeolite traps using both nude'' and tubulated ion gages indicates an appreciable amount of untrapped vapors passing through the unrefrigerated zeolite. The exact nature of this vapor was not determined. Investigations of the all stainless steel vacuum system indicate that the large source of desorbed H/sub 2/ is that adsorbed in the walls. Other work is reported on low temperature cathodes and construction of an ionization gage incorporating a SiC emitter and an electron multiplier. A system to give semi-quantitative data on the solution of H/sub 2/ in W, as a function of temperature, was assembled and is being tested."

"Investigations were continued on the characteristics of zeolite traps and on a small cryopump. Studies of an all metal vacuum system indicated that this system is superior to glass systems when operated at elevated temperatures. The major contribution to the gas evolution is hydrogen. The characteristics of an electron multiplier operating under ultrahigh vacuum procedures were studied. The desorption of gas by photons is being investigated."

"The photodesorption of gases from metals by uv photons has been studied with a high sensitivity mass spectrometer. A program to develop low-temperature cathodes is underway to study hydrogen interactions at various surfaces. Preliminary results on the degassing characteristics of an all metal system have been obtained."

"Dissociative attachment studies were made for the production of H/sup -/ and 0/sup -/ ions in the electron bombardment of water vapor with a cycloidal instrument to compare the results with previous data obtained with mass spectrometers and total ionization tubes. The peak heights were studied as a function of spectrometer operating conditions to obtain confidence in the present data with regard to the relative intensities. Graphical representations are included of the results along with a schematic of the apparatus used in the study."

"Electron emission during the adsorption of a monolayer of oxygen on a clean'' tungsten surface is reported. This emission is attributed to the excitation of conduction band electrons during adsorption, probably as the result of Auger transitions to the chemisorbed state. Calculations based on this model of chemisorption agree qualitatively with the experimental yield."

"The model seal test program was concluded during this Quarterly Report. The final test, 1014 hours in duration, was conducted at a sea1ing pressure of between 2100 to 2300 psig and at a leakage rate of 2.14 gph. The seal face materials evaluated were an aluminum oxide rotor running against a stator face made of tungsten carbide for the high pressure seal and Graphitiar 39 for the low pressure element. Optical examination of the faces after the test showed no measurable wear. Nine unscheduled shutdowns were made during the test without damaging the seal faces or affecting the performance of the seal after each startup. The shutdowns were automatically accomplished in a predetermined sequence through a control system which was calibrated to monitor the test and stop it in the advent of equipment failure. The manufacture of the full size seal (51/2-inch shaft diameter) is 50% complete. All of the test equipment and instrumentation for the full size test rig has been received and assembled. The full size seal is scheduled for assembly by mid August 1963."

"The model seal test program was continued throughout the period covered by this report. Of notable mention, a test, 507 hours in duration, was conducted at 2000 psig and 2.75 GPH leakage. Examination of the seal faces after the test showed that there was no measurable wear within the limits of an optical inspection. The full size seal (5-1/2" shaft diameter) and the related test strand are in the manufacturing phase. The instrumentation and associated equipment for the full size seal test are on order."

"The full size seal (5 1/2" shaft diameter) was redesigned to incorporate the latest seal geometry which was developed as a result of the model seal test program. A number of compatible seal face material combinations, which performed satisfactorily during the model seal test program, was also selected for evaluation in the full size seal. All the detail drawings of the seal and test stand were completed. A test program for the full size seal was prepared and approved."

"The potential of closed-cycle gas turbines for producing a highly efficient nuclear power plant is discussed. Such turbines are being developed for three applications: the HTRE program (Heat Transfer Reactor Experiment) for nuclear aircraft propulsion, the MGCR program (Marine Gas Cooled Reactor) for nuclear marine propulsion, and the ML-1 (Mobile Low-Power Gas-Cooled Nuclear Power Plant) for nuclear electric power generation in an Army mobile power plant as part of the Army Gas-Cooled Reactor Systems Program (AGCRSP). Some characteristics of several non-nuclear gas turbines as well as gas turbine prime movers of 18 U.S. gas-cooled nuclear power plant projects were examined. Turbine and compressor performance, performance improvement, full-load and part load operation, maintenance, component life, and reliability are discussed. Consideration is given to factors affecting structural integrity of turbomachinery, such as choice of proper materials, vibrations, cooling, and construction features. The material reported is based on information obtained in part from the 155 references included and in part from the data requested from some 60 manufacturers."

"Various existing circulator types suitable for primary loops of gas- cooled nuclear power plants are discussed. Operating characteristics, drive systems, structural problems, and maintenance questions are analyzed. The present state of the art is established and requirements, availability, development areas, and limiting factors are indicated. Several existing test- loop gas circulators are included in the general discussion."

"The state-of-the-art of heat exchangers for gas-cooled reactor primary circuits is established by describing steam generators, primary heat exchangers, recuperators, and coolers of a number of gas-cooled nuclear projects, and by listing plant and exchanger main characteristics in three summery tables. Information is based in part on references indicated and in par+ on data from manufacturers. The availability of suitable heat exchangers is represented in the form of 35 Data Sheets submitted by manufacturers in response to our request. A list of manufacturers and their addresses is appended."

"Expressions were derived for cycle thermal efficiency, work ratio, related useful work, and relative temperatures, and pressures at significant stations, all for a representative direct closed gas-turbine cycle. A parametric study of this cycle was performed for He and N/sub-2/ as coolants. Results of this parametric study are given in tables and charts. Four different cycles, corresponding to the maximum cycle temperatures equal to 1300, 1500, 1700, and 2000 deg F, were established for each of the gases. On the basis of these cycles, consistent form sheets were prepared for inquiries to manufacturers regarding their capabilities and availability of components."

"Helium, nitrogen, carbon dioxide, and other gases suitable as reactor coolants were evaluated. It is shown that because of the helium conservation program, recently authorized by legislation, sufficient helium will become available for domestic power plants and for the requirements of the Euratom group. Tables of thermodynamic properties for helium and molecular nitrogen were computed from the Beattie-Bridgman equation of state. Specific enthalpy, specific entropy, isobaric specific heat, specific heat ratio, compressibility factor, specific volume, and acoustic velocity are tabulated over the range helium and molecular nitrogen are given."

"The natural exponential decay of a radioisotope used as a heat source for a thermoelectric generator makes the use of a power flattening'' device highly desirable, especially when the duration of the mission is large compared to the half-life of the radioisotope. Power-flattening devices are considered which either dump excess heat outside the thermoelectric generator or use the characteristics of the generator to absorb the excess heat and thereby regulate the hot junction temperature. A number of power-flattening devices were studied both analytically and experimentally with a view toward operability in space. The most promising concepts are (a) to utilize a secondary radiator of variable area; (b) to provide thermal shunts that are sequentially removed during the mission; (c) to use a secondary radiator coupled to the heat source through a slowly evaporating thermal connection."