An atomic-beam magnetic-resonance apparatus operating on the flop-in principle was used to measure the nuclear spins and hyperfine-structure separations of the /sup 2/S/sub 1/2, electronic ground state for several radioactive isotopes of silver and gold. The results of these experiments, together with calculated values of the nuclear magnetic-dipole moments, are given (auth)

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A manipulator or mechanical arm involves an upper and a lower arm, with a variable angle between them. Cables used to transmit motion and force from the upper to the lower arms pass over a pulley at the joint or elbow. A pulley, axiaily fixed with respect to the joint, imposes a change in length of the cable as the angle between the arms varies. Manipulation design requires a cable of constant length during this variation; this constant length may be achieved by guiding the center of the pulley along the proper path. Acceptable solutions were obtained in terms of variables such as the lengths of each arm, the radius of the pulley, and the angle between the arms. In one design the pulley center is moved along a straight line with respect to the lower arm, while in the other solution the pulley center is moved along a circular arc with respect to the upper amn. Practical and economical mechanisms based on these solutions were investigated for use in manipulator design. (auth)

The atomic-beam magnetic-resonance flop-in technique using radioactive detection was employed to measure the nuclear spins doff B/sup 206/ , Ti/sup 200/ , Tl/sup 201/ Tl/sup 202, In/sup 09. ln/sup 110m/ and In/sup 111/. In addition the magnetic-dipole and constatns of In/sup 109/, In/sup 110m/, ined. the signs of the In/sup 110m/ con-, stants were not determined. Results, theory, procedure, and data reduction are given. (auth)

The possibility of measuring the electromagnetic form factor of the pion by extrapolation of the cross section for e/sup -/ + p 1100 deg C are n + The effects of /sup +/ + e/sup -/ was investigated. The method is based on the existence of a pole in the electropionproduction scattering amplitude as a function of the invariant momentum-transfer of the nucleon. The residue of this pole is the pion form factor multiplied by a known coefficient. Since the pole lies slightly outside the physical region of the invariant momentum transfer, an extrapolation of the experimental data is required. An approximate calculation of the electropion-production cross section was made in order to estimate the experimental accuracy necessary for a significant extrapolation. Accuracy is required which is an order of magnitude better than that achieved at present in similar experiments. (auth)

The Cd/sup 115m/ and Cd/sup 115/ isomers produced in 12- to 340Mev proton bombardments of U/sup 238/ were isolated by radiochemical methods. The cumulative yield ratios of Cd/sup 115/Cd/sup 115m/Cd/ were determined. In the 45- Mev heliumion flssion of uranium, an estimation of the independentyield ratio of Pm/sup 148/ (5.3-day) to Pm/sup 148/ (43-day) was made. In the deuteron fission of uranium at about 20 Mevs an estimate of the independent-yield ratio of Nb/sup 95m/ to the total niobium of mass 95 was made. A literature survey on experimental isomer ratios from fission was made. The yield ratio of Sc/sup 44// Sc/sup 44/ was measured in Sc/sup 45/ ( alpha , alpha n)Sc/sup 44/ reactions with helium ions of energies between 20 and 43 Mev and at 320 Mev. The Sc/sup 44m/Sc/ sup 44/ ratio was measured in K/sup 41/( alpha ,n)Sc/sup 44/ reactions at 10 and 43 Mev. The compound-nucleus model was used to calcalate the Sc/sup 44m/Sc/sup 44/ ratios produced by the reactions /sup n44/ and Sc/sup 45/(p,pn)Sc/sup 44/ at energies 0.4 Mev above threshold. Agreement between the experimental and calculated Sc/sup 44m/Sc/sup 44/ ratio was obtained for the K/sup 41/(l0-Mev alpha ,n)Sc/sup 44/ reaction. A classical knock-on …

The products from the flssion of U induced by charged particles were studied in a mass spectrometer. Both U/sup 238/ and U/sup 235/ were bombarded with 45.7- and 24-Mev helium ions, and U/sup 238/ was also bombarded with 730-Mev protons and 100-Mev carbon ions. Tbe total chain-yields in the region of the rare-earth elemerts (mass 140 to mass 155) for most of the above bombardments and a thermal-neutron bombardment of U/sup 235/ were studied by using the isotopicdilution technique. Independent yields were measured for all the above bombardnnents for several shielded nuclides. (auth)

Submitted to Rensselaer Polytechnic Inst. The computation of reactor characteristics over a fuel cycle in a way suitable to the investigation of the control aspects of the reactor problem is considered. The dynamic problem including as independent variables the neutron energy, the spaces and time was studied. An additional condttion of versatility in the method used to obtain the solutions is necessary to explore the control aspects of the problem. The normal possibilities of the analog computers were surveyed, and a method was found to solve the reactor dynamic problem. The classical approach of considering the neutron energy dependency in groups and the spatial dependency in reactor regions is used. Only cases of regular symmetry are considered, so that the reactor three dimensional configuration is reduced by analytical methods to the study involving one space coordinate. Time is considered as a continuous variable. The Mighty Mouse Deactor is simulated, and the analog results are compared against published data. With the spatial dependency represented by three core and three reflector regions, the fast and slow flux distributions are within 5% of the digital computer solution of the same problem. At the end of the fuel cycles the flux distribution is essentially …

please delete the no. 17076<><DSN>13:017077<ABS>The P/sub 1/ multigroup code was written for the IBM-704 in order to determine the accuracy of the few- group diffusion scheme with various imposed conditions and also to provide an alternate computational method when this scheme fails to be sufficiently accurate. The code solves for the spatially dependent multigroup flux, taking into account such nuclear phenomena is slowing down of neutrons resulting from elastic and inelastic scattering, the removal of neutrons resulting from epithermal capture and fission resonances, and the regeneration of fist neutrons resulting from fissioning which may occur in any of as many as 80 fast multigroups or in the one thermal group. The code will accept as input a physical description of the reactor (that is: slab, cylindrical, or spherical geometry, number of points and regions, composition description group dependent boundary condition, transverse buckling, and mesh sizes) and a prepared library of nuclear properties of all the isotopes in each composition. The code will produce as output multigroup fluxes, currents, and isotopic slowing-down densities, in addition to pointwise and regionwise few-group macroscopic cross sections. (auth)

The determination of the specific radioactivities of the chlorophylls and carotenoids of algae after photosynthesis with C/sup 14/O/sub 2/ is a formidable task, due to the extreme lability of these compounds. The whole success of the method depends on adequate chromatographic separations of the pigments from the colorless contaminants which are closely associated with them, and yet the time involved for such separations is sufficient for marked decomposition of the pigments to occur. It is suggested that the techniques of column chromatography, followed by centrifugallyaccelerated paper chromatography of the spectroscopically pure pigments, may resolve this problem. In an investigation of the action of cyanide on photosynthesis, green algae have been treated with radioactive cyanide. A multitude of products have been found to be formed in very short exposure times. One of these was identified with a material formed when algae are given radioactive CO/sub 2/ and nonradioactive KCN. This material has been identified as the cyanide addition product of ribulose-1,5- diphosphate. Upon hydrolysis it gives a branched-chain sugar acid (or mixture of isomers) closely related to hamamelonic acid. Perhaps the most important aspect of this work is the demonstration of the chemlcal role of cyanide. (auth)

The dynamic behavior of a fast reactor, when the neutron flux is considered as a function of time, is considered. The kinetics of a fast reactor can be grouped into three distinct areas of interest; the first being the normal operating conditions where all the changes are brought about in a slow manner. and the resulting flux changes being small in comparison with the steady stuff flux. Since the available reactivity and the power density of most large thermal reactors is so small, and the heat capacity is so large, nothing but small deviations from design conditions would occur before the control rods were inserted. Thus reactor kinetics traditionally has meant linear kinetics, which in the mathematical interpretation leads to linearized kinetic equations. The second area is where there is much stronger coupling between reactivity and geometrical changes in the core. A fast reactor has a much higher power density than a thermal reactor and geometrical changes will therefore be more effective on reactivity. A fast reactor needs a greater total amount of U-235 because the fission cross section of U-235 is several hundred times smaller at neutron energies of the order of 0.1 Mev as compared to thermal energies. …

BS>Results of a study of thermodynamic properties of aqueous hydrochloric acid solutions are presented. A hydrogen electrode was used against a silver-silver chloride electrode at 25 to 275 deg C using hydrogen pressure of about 1 atm. and hydrochloric acid concentrations of 0.005 to 1.0 M. Electromotive measurement techniques are described and resulting data are tabulated. (J.R.D.)

A study concerned with the determination of the limiting hydrodynamic conditions which characterize nucleate and transitional boiling was conducted. The critical heat flux and the minimum heat flux are derived from these hydrodynamic limits. Results of investigations of nucleate boilin g are discussed and the theory of bubble growth is extended to include the effect of non-uniform temperature fields. An equation is derived for the product bubble diameter times frequency of bubble emission, and data showing that the diameter of nucleating cavities can he related to the heat flux density and superheat difference are presented. (J.R.D.)

Atomic-beam magnetic resonance techniques were used to measure the nuclear spins of I/sup 123/, I/sup 124/, I/sup 126/, I/sup 130/, I/sup 132/, I/ sup 133/, I/sup 135/, and At/sup 211/. Also, measurements of the magnetic-dipole interaction constant, and the electroquadrupole interaction constant, and the electroquadrupole interaction constant for I/sup 131/ and I/sup 132/ are reported. The design of the atomic-beam apparatus is described. Experimental methods and sample preparation are discussed and results are interpreted in the light of the single particle shell-model theory of nuclear structure. (J.R.D.)

Foliar absorption rates for phosphorus-32 and calcium-45 in beam plants were determined. (C.H.)

The range and range straggling of 96.8-kev Ra/sup 224/ recoil atoms produced by alpha decay of Th/sup 228/ have been measured in H/sub 2/, D/sub 2/, He, N/sub 2/, Ne, and Ar by a charged, parallelplate, collection technique. The range and range straggling of 725-kev Th/sup 226/ recoii atoms produced by bombardments of Ra/sup 226/ with 41.6-Mev helium ions have been measured in D/sub 2/, He, N/sub 2/, and Ar by this same technique. Experimental results seem to indicate that the range-energy relation for the stopping of heavy recoils by nuclear collisions is not linear, as is theoretically predicted by Bohr. The distribution of ranges about the mean range appears to be Gaussian. Various factors contributing errors to the measured range stragglings are discussed in detail P coil efflciencies of the heavy recoils produced in the (d,) (d,2n), (d,3n), and (d,p) reactions of Bi/sup 209/ have been measured at incident deuteron energies of 15 0 to 23.6 Mev for Bi/sup 209/ targets of 0 6 to 42.5 mu g/cm. The recoil effic encies of the different reaction products have been compared on the basis of probable nuclear-reaction mechanism by which they are produced. Mean ranges for Po/sup 208/ in Bi/sup …

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