The reactivity lifetime of a water-moderated, thermal, power reactor using a low enrichment fuel is, in part, dependent upon the conversion ratio. The High Conversion Critical Experiment (Hi-C) was initiated at Argonne to extend the rage of investigations with light water moderated, slightly enriched, oxide-fueled cores. Bucklings were obtained from the clean critical core size and reflector savings values. The so-called "integral" technique was used to measure the disadvantage factor.

Abstract: Various mechanisms for the formation of point defects in ionic crystals are considered. Their probable importance as a function of the energy of the ionizing radiation and the temperature at which the irradiation takes place is discussed. Complex centers formed from aggregates of simple point defects are reviewed and their occurrence considered in terms of the expected spatial distribution of the point defects. The effect of high energy x rays and protons on the ionic conductivity is discussed in terms of a new interpretation of the conductivity curve as a function of temperature, and it is suggested that radiation-enhanced diffusion may be important in explaining the experimental data.

Abstract: the goal of research on elastic scattering of atomic (or molecular) beams is the elucidation of the interaction potential V(r). the present discussion is confined to thermal energy collisions ([less than]1 ev), sensitive primarily to the attractive part of the potential. Studies of the velocity dependence of the differential and total elastic scattering cross sections have yielded information as follows: (1) The functional form of the long-range attraction : V[tilde]-C/r6, from differential cross sections I(0), at low angles: I(0) oc 0-7/3. (2) The attractive potential constant C, from total cross sections: Q oc (C/v)2/5, (3) The depth of the potential well [epsilon], from the rainbow effect in I(0): 0r=f(1/2mv2/[epsilon). (4) The equilibrium separation rm, from de Broglie interference producing undulations in (I0). (5) the product [epsilon]rm, from extrema in Q(v), and thus rm (from absolute Q's). (6) Observations of m maxima in plots of vQ5/2 vx. v-1 (termed elastic impact spectra) implied the existence of at least m bound states (discrete vibrational levels of zero angular momentum for the composite system).

Abstract: the goal of research on elastic scattering of atomic (or molecular) beams is the elucidation of the interaction potential V(r). the present discussion is confined to thermal energy collisions ([less than]1 ev), sensitive primarily to the attractive part of the potential. Studies of the velocity dependence of the differential and total elastic scattering cross sections have yielded information as follows: (1) The functional form of the long-range attraction : V[tilde]-C/r6, from differential cross sections I(0), at low angles: I(0) oc 0-7/3. (2) The attractive potential constant C, from total cross sections: Q oc (C/v)2/5, (3) The depth of the potential well [epsilon], from the rainbow effect in I(0): 0r=f(1/2mv2/[epsilon). (4) The equilibrium separation rm, from de Broglie interference producing undulations in (I0). (5) the product [epsilon]rm, from extrema in Q(v), and thus rm (from absolute Q's). (6) Observations of m maxima in plots of vQ5/2 vx. v-1 (termed elastic impact spectra) implied the existence of at least m bound states (discrete vibrational levels of zero angular momentum for the composite system).

Abstract: This report is concerned with the application of an electronic data processing system to the unique combination of scientific and commercial data processing requirement of nuclear materials management. The organization and flow of data from the plant through the data processing equipment to the final report is the principle topic of the report. Included in the discussion, however, are topics concerned with the impact of conversion to electronic data processing on personnel, materials management costs, and on other plant organizations. Portions of the report are devoted to programming systems and decision-making abilities of data processing equipment which make these systems readily adaptable to nuclear materials management.

Abstract: The current-carrying capacity of Nb- Zr wire has been studied under conditions of swept magnetic field and fixed wire current and of fixed magnetic field and swept wire current. The effects of wire movement, thermal environment, copper coating of the wire, and rate of sweep of wire current or magnetic field have been determined for these conditions of test.

Diffusion coefficients and bucklings are measured for UO/sub 2/ fuel tube assemblies in D/sub 2/O moderated lattices. The effects of H/sub 2/O fogs and air in the coolant channels in place of D/sub 2/O are studied.

Abstract: A thermal K beam was velocity selected, and scattered by Ne, Ar, and Xe gases. The dependence of the total cross section on relative velocity is approximately v/sup -0.4/ for K--Ar and K--Xe, and v/sup 0.8/ for K--Ne. The average relative velocity ranges were 400 to 1430 m/sec for Ne, 480 to 1350 m/sec for Ar, and 380 to 1320 m/sec for Xe. The dependence of the cross section on relative velocity was obtained by removing the cross section from the collision frequency integral. For the v/sup -0.4/ dependences, this gives results correct to 3%. For the v/sup -0.8/ dependences, the error is most likely greater. Three gas temperatures were used: liquid air, room, and 200 deg C. The results for a given gas at different temperatures are consistent with kinetic theory predictions.

Abstract: Recent developments in techniques for low-voltage radiography have found application for the examination and evaluation of minute details in small or thin specimens. Utilization of x-ray tubes and helium chambers with thin windows for maximum transmission of soft x rays and bare film with dark-room exposure techniques have allowed very high contrast radiographs to be produced on low-contrast materials. These conditions, coupled with very high resolution photographic emulsion detectors, have resulted in the observation of detail approximately 1 {micron} in size. Useful examination of the plates and subsequent reproductions have been made at magnifications as high as 500X. This contact system offers the advantage of evaluation of a relatively large area, as compared to the restricted field of observation of projection microradiography. Included among the subjects have been graphite-coated UC₂ particles, graphite, beryllium, paper, and other organic specimens.

When a beam of X-rays penetrates through a layer of material, the intensity of the beam is reduced by absorption. some of the energy that has been absorbed may be re-emitted as X-ray quanta, by the atoms that absorbed it, at a wavelength characteristic of the emitting atom but longer than the quantum absorbed. Four methods of measuring thin films that use X-ray emission apparatus have been described, each of which is useful over a limited range of thickness, and for certain kinds of samples.

Abstract. the direct and inert-gas radiolysis, as well as the vacuum ultra-violet photolysis of CD3CH2CD3, CH3CD2CH3 and C3H2+C3D3 mixtures have been investigated in the presence of radical scavengers. The major conclusions are : (a) at atmospheric pressures, neutral propane decomposition contributes to the observed products although to a lesser extent than parent ion decompositions ; (b) a variation in pressure has a pronounced effect on the fragmentation of the parent ion ; (c) the hydrogen atoms in the ethyl ion are randomized in the direct as well as in the inert-gas sensitized radiolysis ; (d) rearrangement in the parent ion is of minor importance in the radiolysis ; (e) although the formation of propylene is related to the propyl ion, it is not necessarily produced by the neutralization of this ion.

Abstract. An a priori calculation of the radiolysis of oxygen gas in the pressure ; range 10-3 to 100 atm has been made. In the low background region (1- 100 atm) all track effects have been considered. The calculated G(O3) values seem to be in reasonable agreement with experiment if only one excited oxygen molecule is initially formed per ion pair. Effects of pressure, LET and dose rate have been discussed. The radiation-induced chain decomposition of O3 has not been considered.

Abstract. By means of the pulse radiolysis technique a short-lived transient species has been observed in irradiated de-aerated ethanol and methanol, exhibiting an optical absorption throughout the visible and near infra-red. This transient is suggested to be the solvated electron on the basis of the nature of the spectrum, the reactivity with hydrogen ion and with various organic electron acceptors, and the formation of mononegative ions of some of these acceptors. The absolute rate constants have been determined for the reactions of the solvated electron with hydrogen ion, oxygen and benzyl chloride in ethanol and methanol. The diphenylide ion was found to be short-lived in ethanol. The absolute rate constant for the first-order decay of the diphenylide ion has been determined.

Abstract. The rate constants for the reaction of the hydrated electron eaq with a number of solutes and with radicals formed in water radiolysis are reported. Hydrated electrons were formed in the electron pulse irradiated solutions at concentrations in the range from 1 to 10 pM. Their reaction was followed by the decay of the optical absorption of eaq at 5780 A. Generally a 04 psec pulse of 15 MeV electrons was used. In the absence of eaq scavengers, second-order kinetics prevailed owing to the dominance of the reactions,eaq+eaq, eaq+H, and eaq+H202 when OH radical scavengers were present in alkaline solution. An analysis of the decay curves leads to values for keaq+eaq and keaq+H of 0.9~ 1010 and 3 x 1010 M-1 sec-1, respectively. With scavenger present in excess over [eaq], pseudo first-order kinetics were found and rate constants for a number of inorganic and organic compounds are reported. The agreement of these and other rate constants with diffusion-controlled reaction theory is discussed.

Abstract: The exhibit shows that colloidal aggregates (10 to 20 mu) of human serum albumin I131 may be used safely by intravenous injection to perform photoscans of the heart, liver, spleen, stomach, and salivary glands in man. Large particle size suspensions (10 to 50 mu) of the same material are being investigated experimentally in animals for scanning the lungs after intravenous injection and the brain following injection into an internal carotid artery. The advantages of this test material are the relatively low radiation exposure to the target organs and the number of organs that may be examined. Radiation exposure is low because of the rapid turnover in the target organs and removal from the body, mainly by urinary excretion, within 72 hours. The mechanism of liver-spleen localization with this organic colloid is the same as for inorganic colloidal radiogold198, namely, rapid removal from the blood by the phagocytic cells of the liver and spleen. However, in contrast to the inorganic colloid, which remains in the phagocytic cells permanently, albumin is digested by proteolytic enzymes and the I131 abel is set free to re-enter the general circulation. With the thyroid blocked, the I131 is excreted mainly in the urine as free …

Many measurement of neutron spectra have been made in water assemblies. In these system a large part of the spectrum is given by an essentially Maxwellian distribution at the moderator temperature which is insensitive to the scattering model. Hence, the test of the energy exchange scattering kernel is in the difference of the spectrum and the fundamental or Maxwellian component. The figure shows the spectrum for the Nelkin model. Once the fundamental has been subtracted neither theoretical model seems to fit the data extremely well. Below kT the Nelkin model is a closer fit than the gas model but it underestimates the deviation from the Maxwellian whereas in the joining region it overestimates the distortion.

Investigation of whether the multi-thousand psi pressure pulses that occurred in the BORAX-I and SPERT-I destructive power excursion could have been generated by thermal mechanisms in the geometries of unmolten reactor cores. These pressure pulses were "at least as high as 6,000 psi, and probably higher than 10,000 psi " in BORAX I, and "between 3,000 and 4,000 lb/in" in SPERT I. An experimental investigation was undertaken of pressure pulse generation by purely thermal means.

Abstract: The use of a high energy proton or electron beam, directed vertically to act as a probe for the study of atmospheric processes is proposed. An outstanding feature of such an atmospheric probe is its capability to ionize a column of air repeatedly in a few microseconds and in approximately the same place. Characteristics of a vertical proton beam which may be generated by the Zero Gradient Synchrotron at the Argonne National Laboratory are discussed and calculations are presented to provide an estimate of the ion concentration as a function of height in the atmosphere. The potential uses of an atmospheric ionized column for meteorological research are discussed such investigations include the artificial initiation of lightning, the production of atmospheric ozone resulting from lightning, and the line spectra associated wit the lightning channel. Also presented is a method whereby a combination of the igh energy particle beam and infrared techniques may be used to determine the air circulation within a thunderstorm. Brief mention is made of the possible uses of a high energy particle beam for aerospace sciences, such as the study of whistlers and elecro-magnetic radiation phenomenon associated with the aurora and airglow.

Abstract. A brief review of the development of the subject of lattice defects in solids is given. The relation of this problem to field theory methodology is discussed; the defect is regarded as a particle imbedded in the phonon field. One may then discuss scattering states in the field, or “dressed” states of the particle. Specific application is then made to a defect in a simple cubic crystal including interactions between the defect site and its six nearest neighbors. Scattering solutions and scattering cross-sections are calculated and show that vacancies can cause strong resonant scattering, or pseudo-localized modes, at frequencies well below the Debye frequency. Applications to thermal conductivity and other experiments are discussed briefly.

Abstract. Some diffusion parameters of water are computed with various thermal-neutron scattering laws. It is found that the diffusion cooling coefficient, in particular, is reasonably sensitive to the scattering law, but that the diffusion cooling coefficients predicted by the Radkowsky and Nelkin kernels are in fortuitious agreement. The coefficients computed for the Nelkin kernel, when treated in a manner consistent with the way in which experimental data are treated, are in reasonable agreement with the results of a recent experiment.

Summary: The use of dimensionless-parameter frequency response diagrams to determine accuracies of lumped-parameter approximations is demonstrated by two examples: calculation of the heat flux at the surface of a semi-infinite solid due to temperature fluctuations of an adjacent fluid; and the response of a counterflow heat exchanger to inlet fluid temperature perturbations. Dimensionless system parameters make it possible to use general-purpose plots to find the error in particular approximations as a function of the frequency of perturbation. Such plots are directly applicable to control-system stability problems, where the highest frequency of interest is usually apparent.

Abstract: A pilot plant facility for recovering Pu238 and unconverted neptunium from irradiated neptunium target elements was operated for 17 months at the Savannah River Laboratory. The process required that the irradiated target elements be dissolved and the solution be processed through three anion exchange cycles for removal of undesirable fission products and cations, recovery of unconverted neptunium, and concentration of Pu238 solution. The process equipment was enclosed in three stainless steel boxes that were installed in two general-purpose cells of a ten-cell complex. The basic cells were not modified. The two cells were not separated from from the adjacent 8 cells. Containment of the high-specific-activity alpha emitters was accomplished by ventilation, development of handling techniques, use of procedures, and close Radiation Control coverage. The facility was dismantled, and the cells were decontaminated and returned to normal use. With the exception of an accidental overexposure, all personnel exposures were kept below the administrative level of 3 R/yr. None of the personnel assimilated detectable amounts of he material handled.

Montgomery and Chandrasekhar and Hulm suggested models for predicting Im and Hm of high-field superconducting solenoids. Montgomery's model for predicting the degradation effect of superconducting solenoids leads to a unique coil quenching characteristics if geometrically similar solenoids are considered. Experiments do not verify these predicted results. Chandrasekhar and Hulm's model leads to one unique coil quenching characteristic for all solenoids with identical wire type and turn distance; coils with identical load factor should display identical values im and Hm. An analysis of the surface currents in an ideal superconducting infinitely long solenoid demonstrated possible forms of shielding currents. Experiments with Pb coils with and without NbZr and compensation agree with results expected from this analysis, but contradict Chandrasekhar and Hulm's model. Measurements of individual turn resistances show behavior of a soft superconductor solenoid in the intermediate state.

Abstract. The kangaroo rat is readily tamed and has certain characteristics that make it unique and of interest in highly specialized research programs. Studies were conducted on its ability to exist on a dried diet with only a bare minimum of water and that obtained from succulent plants. Hematological studies indicate that the kangaroo rat exhibits a different hematological distribution of cells than the mouse or rat. The lymphocyte constitutes 81.4% of the total leuokocytes. The hematocrit has a value of 46 to 48 in spite of the high degree of water conservation practiced by the animal. The response to ionizing radiation of this species does not differ from that reported for the mouse or rat. Behavior studies indicate that the digging characteristics of the kangaroo rat are similar to those of the gerbil. Furthermore, the animal shows definite psychotic tendencies under the influence of psychotomimetics like LSD-25 and psilocybin. An evaluation of the physiological responses of isolated tissues from this animal as well as its responses to anesthetics is being undertaken to evaluate its further usefulness in the laboratory.